Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    New tuna regimes
    Yeeting, Agnes David - \ 2017
    Wageningen University. Promotor(en): S.R. Bush, co-promotor(en): H.P. Weikard; V. Ram-Bidesi; M. Bailey. - Wageningen : Wageningen University - ISBN 9789463438308 - 154
    fisheries - marine fisheries - tuna - sustainability - environmental policy - governance - economic policy - pacific ocean - environmental economics - visserij - zeevisserij - tonijn - duurzaamheid (sustainability) - milieubeleid - governance - economisch beleid - grote oceaan - milieueconomie
    governing sustainability and equity in the Western and Central Pacific Ocean
    Towards sustainable tuna fishing: understanding the role of private incentive mechanisms
    Tolentino-Zondervan, Frazen - \ 2017
    Wageningen University. Promotor(en): A.G.J.M. Oude Lansink; S.R. Bush, co-promotor(en): P.B.M. Berentsen. - Wageningen : Wageningen University - ISBN 9789463436236 - 205
    tuna - fishing - sustainability - sea fishing - marine fisheries - marine animals - environmental protection - value chain analysis - decision making - philippines - south east asia - business economics - tonijn - vis vangen - duurzaamheid (sustainability) - sportzeevisserij - zeevisserij - zeedieren - milieubescherming - waardeketenanalyse - besluitvorming - filippijnen - zuidoost-azië - bedrijfseconomie

    Unsustainable fishing practices, including the use of non-selective fishing methods and Illegal Unreported and Unregulated (IUU) fishing, contribute to the decline of tuna fish stocks in the Western and Central Pacific Ocean (WCPO). This has led to emergence of different public and private governance arrangements to foster the sustainable exploitation of tuna stocks. This thesis focuses on the performance of three innovative private incentive mechanisms: Fishery Improvement Projects (FIPs), International Seafood Sustainability Foundation’s Pro-active Vessel Register and eco-FADs, and Marine Stewardship Council (MSC) certification, to deliver economic incentives for improved production. The overall objective of this thesis is to evaluate the extent to which private incentive mechanisms influence Filipino fishers’ decision to improve their fishing practices.

    In order to address the overall objective, this thesis first analyses and compares the ways existing private incentive mechanisms influence the upgrading strategies of Filipino tuna fishers in the value chains (in chapter 2). Second, it evaluates the important determinants for small-scale handline fishers’ decisions to participate in two FIPs for yellowfin tuna in the Philippines (in chapter 3). Third, it examines the effect of MSC certification on the allocation of fishing days by Filipino purse seiners operating in Parties to Nauru Agreement (in chapter 4). And finally, it analyses the profitability of investments in measures needed to comply with private incentive mechanisms by Filipino purse seiners (in chapter 5).

    The findings show that overall, the incentive mechanisms are able to improve the practices of fishers, however only to a limited extent. The first two chapters (chapters 2 and 3) show that producers first need to have the capabilities to meet the requirements of private incentive mechanisms, so that they can be included in the value chain and that they can realise the incentives offered by these mechanisms. However, being capable does not guarantee that producers will improve their practices. As shown in the last two chapters (chapters 4 and 5), producers must also have the willingness to upgrade, based on their risk attitude and on the ability of the economic incentive to cover the additional costs and to compensate for the increase of the risks of participation of producers. Given that producers have the availability of capabilities to upgrade and that the benefit is sufficient to opt for participation, then producers may decide to improve their practices, which may contribute to the sustainability improvement goal of private incentive mechanisms. As a consequence of this finding, the incentives, inclusiveness, and improvements must be taken into account in both the design and implementation of private incentive mechanisms.

    Monitoring cod catches of the Dutch demersal fleet in 2016
    Hal, R. van; Machiels, M.A.M. - \ 2017
    IJmuiden : Wageningen Marine Research (Wageningen Marine Research Report C056/17) - 29
    monitoring - cod - beam trawling - pulse trawling - demersal fisheries - marine fisheries - fish catches - north sea - gadus morhua - monitoring - kabeljauw - boomkorvisserij - pulsvisserij - demersale visserij - zeevisserij - visvangsten - noordzee - gadus morhua
    This report presents the results of the cod monitoring program 2016. The research was commissioned by the Dutch Ministry of Economic Affairs within the EZ-program Beleidsondersteunend Onderzoek. Cod catches of the vessels in the fleet segments BT2 (beam trawl and pulse trawl) and TR (otter trawls and seines) need to be monitored yearly, due to the Dutch implementation of the European cod recovery plan. The European cod recovery plan restricts the fishing effort of European fleets catching cod. Fishing effort, based on historical track records, is allocated to different gear groups. Fishing effort can be transferred between gear groups by use of conversion factors. In the Netherlands fishing effort is transferred yearly from the BT2 gear group to the TR group, based on a national conversion factor of 1:3 (BT:TR) kWdays instead of the European conversion factor of 1:16. This is because the cod catches in the Dutch TR fleet are not as high as the European conversion factor implies. In order to substantiate for the national conversion factor, the Dutch government is obliged to report cod catches per unit of effort (CpUE) of the vessels in these gear groups to the European Commission. An overview is provided of the fishing activity, the cod landings and the cod landings per unit of effort of the various gear categories in the BT2 and the TR fleet segments during the year 2016. First the cod Catch per Unit of Effort (CpUE) transition ratio between the BT2 on the one hand and the TR1C plus TR2 fleet segments on the other hand was calculated. And secondly the percentage of cod avoidance trips – trips during which 5% or less cod was caught – in the TR-fleet were calculated. The TR fleet has a higher cod CpUE on average than the BT fleet. When the cod targeted fisheries (TR1AB) are not taken into account, the CpUE effort transition ratio (TR1C+TR2): BT2 of 2016 lies between 4.2:1 and 5.7:1, depending on whether the ratio is calculated on the basis of minimum or maximum cod discards estimation by the Scientific, Technical and Economic Committee for Fisheries (STECF) respectively whereby in the minimum calculation the vessels participating in the CCTV program are excluded. Based on average discards estimations including all vessels, the ratio is 5.1:1. The percentage of cod avoidance trips, fishing trips with 5% cod or less in the total catches, in the TR1C and the TR2 fleets were 94% and 96% in 2016 respectively. These percentages are based on average STECF cod discards estimations. When minimum or maximum discards estimations are used, the calculated percentages of cod avoidance trips does not vary more than 2 or 3% from the percentage based on average estimations.
    The KB WOT Fisheries Programme carried out in 2015
    Damme, C.J.G. van; Verver, S.W. - \ 2017
    IJmuiden : Stichting Wageningen Research, Centre for Fisheries Research (CVO) (CVO report / Centre for Fisheries Research 16.007) - 57
    visserijbeheer - zeevisserij - visserijbeleid - visbestand - schaal- en schelpdierenvisserij - discards - onderwaterakoestiek - visstand - vismethoden - fishery management - marine fisheries - fishery policy - fishery resources - shellfish fisheries - discards - underwater acoustics - fish stocks - fishing methods
    The KB WOT Fisheries programme is established to maintain and develop the expertise needed to carry out the statutory obligations of the Netherlands in fisheries monitoring and advice. It is also a flexible program which responds to changes over time in WOT requirements, fisheries management and policy needs. While maintaining the core expertise and flexibility, the KB WOT programme also strives to be innovative and participate in the development of fisheries science. The programme operates within the context of the Common Fisheries Policy (CFP), the EU Marine Strategy Framework Directive (MSFD) and the EU Maritime Policy. The KB WOT fisheries programme is established annually and positioned around a number of themes. In 2015 14 projects were originally awarded. However, one project could not meet all the original objectives and with the remaining budget a 15th project was started on the tool development for fish ageing and maturity staging. These 15 projects were successfully completed. The programme focused on the research into the impact of fisheries on the seafloor, development of tools for electronic monitoring, data storage and dissemination and method development for assessment of marine resources. As always the core element of the KB WOT Fisheries was maintaining and developing key expertise for the WOT programme. A large part of the budget was therefore used for projects that standardise fish ageing, provide quality control of discard, ichthyoplankton and shellfish monitoring and development of fisheries acoustics techniques and expertise. These topics are vital for the quality of fish stock assessments and management. Of the 15 projects funded in 2015, seven were carried out in collaboration with institutes outside the Netherlands. As resources and expertise from these other countries contribute to the KB WOT Fisheries programme, these collaborations provided a large amount of added value to the programme. Another large part of the KB WOT resources is specifically dedicated to international collaboration and exchange of science. This ensures that Wageningen Marine Research researchers remain at the centre of scientific developments and international fisheries research. The programme was also very productive in terms of publications, presentations and developing new methods or tools for fisheries research. Over 15 international presentations were given at meetings, workshops and symposia, and 22 international and national reports written. 8 new methods or models were developed, 3 peer reviewed publications published and 5 scientific publications prepared.
    KB WOT Fisheries 2017 : maintaining excellence and innovation in fisheries research
    Damme, C.J.G. van; Verver, S.W. - \ 2017
    IJmuiden : Stichting Wageningen Research, Centre for Fisheries Research (CVO) (CVO report / Centre for Fisheries Research 17.006) - 89
    remote sensing - schaal- en schelpdierenvisserij - visserijbeheer - landmeetapparatuur - discards - visvangsten - zeevisserij - remote sensing - shellfish fisheries - fishery management - surveying instruments - discards - fish catches - marine fisheries
    The KB WOT Fisheries programme is developed to maintain and advance the expertise needed to carry out the statutory obligations in fisheries monitoring and advice of The Netherlands. The contents of the KB WOT Fisheries programme for 2017 reflects the scientific and management needs of the WOT fisheries programme. The strength of KB WOT Fisheries lies in the top-down development of the programme while allowing bottom-up input, with calls for proposals, to secure innovation. To avoid missing research priorities relevant to WOT and EZ needs, the programme is built from a closed call for proposals to WOT Fisheries project leaders. To keep the innovation WOT project leaders are requested to seek input from other Wageningen Marine Research scientists. The KB WOT Fisheries programme will fund 13 projects in 2017 which will focus on remote sensing of fish and shell fish in the ecosystem, new methods and tools for surveys, discard and catch sampling and investigating the effects of fisheries. International exchange of new expertise and developments, as well as continuous quality assurance, forms a major part of the programme.
    The KB WOT Fisheries Programme carried out in 2016
    Damme, C.J.G. van; Verver, S.W. - \ 2017
    IJmuiden : Stichting Wageningen Research, Centre for Fisheries Research (CVO) (CVO report / Centre for Fisheries Research 17.007) - 63
    visserijbeheer - visbestand - visserijbeleid - zeevisserij - schaal- en schelpdierenvisserij - monitoring - onderwaterakoestiek - vis - fishery management - fishery resources - fishery policy - marine fisheries - shellfish fisheries - monitoring - underwater acoustics - fish
    Maintaining and developing the expertises needed to execute the Dutch fisheries monitoring and advice statutory obligations is the core of the KB WOT Fisheries programme. As fisheries management and policy needs, and thus the WOT requirements, change over time, the KB WOT programme needs to be flexible to respond to these changes. The KB WOT programme seeks to be inventive and participate in the fisheries science development, while maintaining the core expertises and flexibility. The programme operates within the context of the Common Fisheries Policy (CFP), the EU Marine Strategy Framework Directive (MSFD) and the EU Maritime Policy. The KB WOT fisheries programme is established annually and positioned around a number of themes. In 2016 17 projects were originally awarded. However, one project could not meet all the original objectives and with the remaining budget a new project was started on the tool development for monitoring catches on board commercial vessels. The 18 projects within the programme were successfully completed. The focus of the programme in 2016 was on research into mapping the seafloor, development of tools and framework for monitoring catches on board commercial vessels, data storage and accessibility and method development for assessment of marine resources. As the basis of the KB WOT Fisheries is maintaining and developing key expertise for the WOT programme, a considerable part of the funds was used for projects that standardise fish ageing, fish and shellfish monitoring and development of fisheries acoustics techniques and expertise. These subjects are essential for ensuring the high quality of fish stock assessments and management. Of the 18 projects funded in 2016, six were carried out in international collaboration with other institutes in- and outside Europe. These partnerships provide a large amount of added value, since resources and expertise from these other countries contribute to the outcomes of the KB WOT Fisheries programme. Also, a large part of the KB WOT resources is specifically dedicated to international collaboration and exchange of science. This ensures that Wageningen Marine Research researchers remain at the centre of scientific developments and international fisheries research. The programme was also very productive in terms of publications, presentations and developing new methods or tools for fisheries research. Over 20 international presentations were given at meetings, workshops and symposia, and 24 international and national reports were written. 9 new methods or models were developed, 4 peer reviewed publications published and 1 scientific publication prepared
    Mission report Kenya : scoping Mission Marine Fisheries Kenya
    Hoof, Luc van; Steins, Nathalie A. - \ 2017
    IJmuiden : Wageningen Marine Research (Wageningen Marine Research report C038/17) - 136
    marine fisheries - food security - aquaculture - seaweeds - trade - kenya - zeevisserij - voedselzekerheid - aquacultuur - zeewieren - handel - kenya
    Mission report Tanzania : scoping mission marine fisheries Tanzania
    Hoof, Luc van; Kraan, Marloes - \ 2017
    IJmuiden : Wageningen Marine Research (Wageningen Marine Research rapport C004/17) - 66
    zeevisserij - visserij - voedselzekerheid - zeewieren - samenwerking - handel - tanzania - marine fisheries - fisheries - food security - seaweeds - cooperation - trade - tanzania
    PMR Monitoring Natuurcompensatie Voordelta-bodemdieren : datarapport campagne bodemschaaf 2015-multivariate analyse 2004-2013
    Craeymeersch, J.A. ; Perdon, J. ; Jol, J. ; Brummelhuis, E.B.M. ; Asch, M. van - \ 2017
    IJmuiden : IMARES Wageningen UR (IMARES rapport C073.16) - 37
    voordelta - bodemarthropoden - bodeminvertebraten - monitoring - gegevensanalyse - zeevisserij - voordelta - soil arthropods - soil invertebrates - monitoring - data analysis - marine fisheries
    Het voorliggende rapport beschrijft de gewijzigde opzet van de monitoring, alsook de eerste monitoring-resultaten d.m.v. een korte beschrijving van de dataset verkregen met de bodemschaaf (omdat de monsters met de box-corer uit 2015 niet tijdig verwerkt waren om in dit rapport opgenomen te worden). Verder wordt de aanvullende studie nader besproken, qua opzet en resultaten van de multivariate analyses.
    Indicatieve impact maatregelen zeebaars : eerste indicatie van de mogelijke impact van zeebaarsbeschermende maatregelen op de Nederlandse zeevisserij
    Strietman, W.J. ; Weegh, J.B.M. op de - \ 2016
    Wageningen : LEI Wageningen UR (Nota / LEI Wageningen UR 2016-007) - 23
    zeebaars - zeevisserij - visserijbeheer - visbestand - bescherming - quota's - milieueffect - nederland - sea bass - marine fisheries - fishery management - fishery resources - protection - quotas - environmental impact - netherlands
    Zeebaars paaigebieden en opgroeigebieden in Nederlandse wateren
    Tulp, I.Y.M. ; Hal, R. van; Damme, C.J.G. van; Smith, S.R. - \ 2016
    IMARES (Rapport / IMARES C060/16) - 35
    visserijbeheer - zeevisserij - visserijbeleid - visbestand - habitatbeheer - nederland - het kanaal (english channel) - kuitschieten - waddenzee - zeeuwse eilanden - boomkorvisserij - zeebaars - noordzee - rijpen - fishery management - marine fisheries - fishery policy - fishery resources - habitat management - netherlands - english channel - spawning - wadden sea - zeeuwse eilanden - beam trawling - sea bass - north sea - maturation
    De zeebaarspopulatie neemt sinds 2010 sterk af door een hoge visserij-inspanning en een lage aanwas van jonge zeebaars sinds 2008. Zeebaars is een langlevende soort die zich pas op latere leeftijd gaat voortplanten. Op een leeftijd van ca 4 jaar en met een lengte vanaf ca 42 cm (vrouwtjes) en 32 cm (mannetjes) beginnen ze paairijp te worden. De huidige minimum aanlandingsmaat van 42 cm heeft als gevolg dat veel vrouwtjes al gevangen worden voordat ze voor het eerst hebben kunnen paaien. Naast vangstbeperkende maatregelen wordt gezocht naar maatregelen ter bescherming van paai- en opgroeigebieden. Hiervoor is ecologische kennis nodig, die voor de Nederlandse wateren nog grotendeels ontbreekt. Aanwezigheid van paaiende volwassen zeebaarzen is direct bewijs voor een paaigebied. Het alternatief is om aan paaigebieden vast te stellen aan de hand van de verspreiding van eieren in een vroeg ontwikkelstadium. Een relatief groot aantal larven en juveniele zeebaars kan wijzen op het belang van een gebied als opgroeigebied. Aanbevelingen voor beleid Gezien de huidige staat van onze kennis, kunnen we nu geen steekhoudende aanbevelingen voor maatregelen gericht op bescherming van gebieden of habitats te geven. De evidentie voor paaigebieden is nog erg dun, de opgroeigebieden zijn wel redelijk bekend, maar over het relatieve belang van elk gebied voor de populatie is nog geen inzicht. Het is duidelijk dat overbevissing een probleem is gezien de ontwikkelingen in de aanlandingen en de afname in gemiddelde lengte bij aanlanding. Het is ook duidelijk dat de zeebaars die in Nederland gevangen wordt in ieder geval voor een groot deel afkomstig is uit het Kanaal en dat de visserij daar in het vroege voorjaar van grote invloed is op de hoeveelheid zeebaars, die later in het jaar in onze wateren terechtkomt. Op basis van de huidige gegevens en inzichten is een verdere inperking van de vangsten door zowel commerciële als recreatieve vissers in ieder geval een effectieve maatregel om de zeebaarsstand te vergroten. Of er in aanvulling daarop ook noodzaak is om gericht gebieden of habitats te beschermen of te verbeteren is met de huidige kennis en gegevens niet vast te stellen en kan alleen met aanvullend onderzoek worden vastgesteld.
    Economic essays on marine invasive species and international fisheries agreements
    Walker, A.N. - \ 2016
    Wageningen University. Promotor(en): Ekko van Ierland, co-promotor(en): Rolf Groeneveld; Hans-Peter Weikard. - Wageningen : Wageningen University - ISBN 9789462576308 - 165
    fisheries - fisheries ecology - agreements - biodiversity - invasive species - europe - marine fisheries - marine fishes - visserij - visserij-ecologie - overeenkomsten - biodiversiteit - invasieve soorten - europa - zeevisserij - zeevissen

    This thesis is divided into two parts, as explained in Chapter 1, which focus on different aspects of marine ecological change. Part A considers marine Invasive Alien Species (IAS), which are taxa introduced outside of their native range. The detrimental consequences of invasions for human welfare necessitate management of IAS. There are two types of IAS management. These are (i) management of the risks that an invasion will become established, termed “prevention”, and (ii) management of already established invasions, termed “control”. Chapter 2 considers prevention of invasive species with Ballast Water Management (BWM). Vessels transport invasive species in their ballast water. BWM involves treating ballast water to reduce the risk of successful invasion establishment. Chapter 2 studies the determinants of optimal ballast water treatment standards from a theoretical perspective. Chapter 3 considers control of already established invasions from a spatial and dynamic perspective. We model a non-native habitat divided into patches, where each patch may contain a population of the invasive species, and where spread of the invasion between patches is a stochastic process. In this context, we derive optimal management policies.

    The second part of this thesis: Part B, considers International Fisheries Agreements (IFAs). IFAs facilitate cooperation in the management of fish stocks. Cooperation is necessary to ensure sustainable management. Part B focuses on two issues which may affect the stability of cooperation within IFAs. These are; in Chapter 4, changes in stock location, which may occur due to climate change, and in Chapter 5, the risk of stock collapse, which may exist due to overfishing. Part B uses game theory to analyse the effects of these two issues on the stability of the Grand Coalition, which is the state of affairs where all parties cooperate to maximize their joint benefit from the fish stock.

    The methods and findings of the thesis are summarized as follows: in Chapter 2 (Part A), we construct a model to study optimal BWM standards. The model is built around the assumption that invasions arriving via ballast water are irreversible, i.e. once an invasion has arrived, it is not possible to reduce the size of the invasive population to zero. The hazard rate of invasion establishment can be reduced by setting a BWM standard. The hazard rate is also affected by the Minimum Viable Population (MVPs) of the species and the possibility of an Allee effect. An MVP exists if there is some population size below which there is an insufficient number of invasive individuals to sustain a population. An Allee effect exists if the probability that a population survives increases at an increasing rate in the size of the population. Our analysis focuses on the conditions under which a BWM standard which aims to reduce invasive populations in ballast water to below their MVPs (as is aimed for by the BWM convention) can be optimal. We find that the current aim of the BWM convention can only be optimal in the case that the hazard function (which determines the hazard rate) is not continuously differentiable around the MVP. We find that Allee effects are a requirement for a continuously differentiable hazard function. Therefore, we find that whether or not an Allee effect exists fundamentally affects whether it is optimal to aim to reduce an invasive population in ballast water to marginally below its MVP.

    In Chapter 3 (Part A), we combine aspects of previous modelling approaches to provide new generalized management insights for controlling established invasions. We employ a metapopulation network consisting of patches which are arranged one-dimensionally (i.e. in a line), which is relevant, among other cases, for invasive species spreading along coastlines. We allow for the population size of the invasion within patches to be reduced, which we term “removal”, and we allow for the probability of spread between patches to be reduced without affecting the population sizes directly, which we term “containment”. We employ numerical stochastic dynamic programming to explore how these two interventions (removal and containment) can be optimally applied to minimize the sum of damages from the invasion and the costs of removing and containing the invasion. We find that allowing for varying stock sizes within patches facilitates optimal timing of the application of containment. We also identify two novel optimal policies: the combination of containment and removal to stop spread between patches and the application of up to four distinct policies for a single patch depending on the size of the invasion in that patch.

    Chapter 4 (Part B) considers how Grand Coalitions can be stabilized in the face of changing stock location. To do so, we employ the Gordon-Schaefer fisheries model. We consider farsightedness as a mechanism by which stability of the Grand Coalition can be increased in the face of changing stock location. Farsightedness allows players to respond to deviations of other players by deviating themselves. This reduces the incentives to leave the Grand Coalition. This is in contrast to shortsightedness, whereby players cannot decide to leave the Grand Coalition in response to such a choice by another player. We begin by modifying the farsightedness concept such that it can be used in games with asymmetric players and transfer payments. We proceed to analyse the modified farsightedness concept in the case where players are symmetric (stock location does not change) in order to identify the properties of the concept in the base case. We find that farsightedness increases Grand Coalition stability with respect to shortsightedness. We proceed to analyse the extent to which farsightedness increases Grand Coalition stability, relative to shortsightedness, as fish stock location changes, using sensitivity analysis. We find that farsightedness increases the stability of the Grand Coalition, but also increases the sensitivity of stability to changes in fish stock location. Thus, for any fish stock location, a Grand Coalition is more likely to be stable if players are farsighted, but shifts between a stable and an unstable Grand Coalition will occur more frequently if players are farsighted.

    In Chapter 5 (Part B), we analyse how the stability of Grand Coalitions is affected by an endogenously determined risk of stock collapse. We do so using the Levhari and Mirman (LM) fisheries model, which is adapted such that there is a risk of stock collapse which increases as the fish stock size decreases. We numerically solve the model and calculate the stability of the Grand Coalition. We find that the effect of an endogenously determined risk of stock collapse depends heavily on the assumptions made regarding how payoffs are determined. A common assumption in the literature is that payoffs are determined at the steady state fish stock. Under this assumption, endogenous risk means that for specific discount and growth rates, a Grand Coalition is stable for any number of players. This is a very different result from the original LM model whereby Grand Coalitions can never be sustained. This is because players can essentially follow two strategies in response to the risk. Firstly, they can attempt to maintain the fish stock by fishing less. In doing so they are running the risk of collapse. Secondly, they can avoid the risk by pre-emptively depleting the fish stock, i.e. harvesting the stock to zero immediately to avoid the risk. Grand Coalitions of any number of players are stable for parameterizations for which a Grand Coalition attempts to maintain a non-zero fish stock and if a deviation from the Grand Coalition would result in pre-emptive depletion. We proceed by relaxing the assumption that payoffs are determined in the steady state by allowing for deviators to obtain payoffs in the transition between steady states. In this case, only Grand Coalitions of two players are stable, and then only for certain parameterizations. The reason is that players can now gain payoffs in the process of pre-emptively depleting the stock, i.e. payoffs are received from the process of fishing the stock down to zero. This increases the benefit of deviating from the Grand Coalition. In this case, Grand Coalitions are only stable for two players for specific parameterizations.

    Chapter 6 summarises the research questions formulated in Chapter 1 and evaluates the work of the thesis. Regarding Chapter 2, we justify our theoretical approach with the following two points. Firstly, BWM management is a global and complex problem, which means that the information required to formally calculate an optimal standard is prohibitively burdensome. Secondly, we argue that the complexity of BWM necessitates a sound theoretical understanding of the problem in order to evaluate the current BWM standard, and also to aid in future policy formulation. Similarly, in Chapter 3, we focus on deriving generalized management insights which are applicable to a variety of real-world cases, as opposed to deriving an optimal management strategy for a specific case. In addition to the data requirements necessary to derive such a management strategy, the complexity of such applied cases leads to potentially excessive computational burden. Chapter 3 analyses systems of two and three patches, which are likely to be too simple to analyse specific real world cases, but are sufficient to derive generalized management insights.

    The game theoretic methodologies in Part B are evaluated principally in terms of the assumptions about changes in stock location in Chapter 4 and the numerical method in Chapter 5. In Chapter 4, the fish stock is conceptualised as existing at a single point in space. The location of this point is determined in relation to fishing nations, which are also conceptualised as single points in space. Changes in stock location result from rises in ocean temperatures due to climate change. Such rises in temperature are likely to lead to other changes in the fish stock such as the size of the area where the fish stock can be found and increases in the maximum fish stock size which the ecosystem can support. These other aspects of changing stock location need to be considered in evaluating Chapter 4, as well as in formulating more applied models. In Chapter 5, a numerical method is adopted to analyse the effects of an endogenous risk of stock collapse. To do so, the utility function in the LM model is adapted such that it can be used in a numerical model. In order to isolate the effect of endogenous risk from changes in the utility function, a validation procedure is carried out by comparing analytically derived results in the deterministic case (without endogenous risk of stock collapse) to numerically derived results in the deterministic case. This reveals that changes to the utility function have a negligible effect and thus the results, in terms of the stability of Grand Coalitions can be attributed solely to endogenous risk of stock collapse.

    Overall, Part A of this thesis presents new insights into the determinants of optimal BWM standards. These insights demonstrate the conditions under which the current BWM standard, which aims to eliminate the risk of invasion establishment, may or may not be optimal. Part A therefore provides a novel theoretical framework which aids in the evaluation of current, and the determination of future standards. Part A also provides new insights into the control of established invasions, by extending existing spatially explicit optimal control models. Specifically, dividing space into patches and allowing for varying invasive population sizes within patches facilitates the optimal timing of management interventions and, in general, more detailed, and thus more efficient, management strategies. Part B provides a novel analysis of the effects of changing stock location on Grand Coalitions by explicitly introducing fish stock location in the analysis, and shows how farsightedness can stabilize Grand Coalitions in the face of such changes. Part B also shows how the effects of an endogenous risk of stock collapse on the stability of Grand Coalitions depends vitally on whether transition payoffs are included. These results can form the basis for more interdisciplinary analyses, analyses of different types of marine ecological change, and analyses of these changes in different settings, such as non-European countries.

    Overleving van discard platvis: vaststellen en verhogen
    Marlen, B. van; Molenaar, P. ; Reijden, K.J. van der; Goudswaard, P.C. ; Bol, R.A. ; Glorius, S.T. ; Theunynck, R. ; Uhlmann, S.S. - \ 2016
    IMARES (Rapport / IMARES C180/15) - 116
    pleuronectiformes - overleving - discards - zeevisserij - visserijbeheer - nederland - pleuronectiformes - survival - discards - marine fisheries - fishery management - netherlands
    On the possibility of RTCs in the Dutch demersal fishery
    Verkempynck, R. ; Machiels, M.A.M. - \ 2016
    IMARES (Report / IMARES C012/16) - 32
    marine fisheries - discards - monitoring - fishery management - netherlands - zeevisserij - discards - monitoring - visserijbeheer - nederland
    VISNED has asked IMARES to do conduct a short feasibility study on the possibility of Real time closures (RTCs) as a tool for the Dutch demersal fishery to cope with the landing obligation (EU regulation 1380/2013). This assignment is part of the EVF-project “Innovatieve discardvermindering in de praktijk” (Innovative discard reduction in practice). In this report we present a short overview of examples of (real time)-closures in Europe. Additionally, known advantages and disadvantages are listed. Next we present discard maps that are based on data from the yearly Dutch discard monitoring and ongoing VIP projects collecting discards. Two sources of data are currently available. We discuss the suitability of these maps and the information they deliver as a driver for a possible RTC system.
    VIP report "Use of new broadband echosounder" : Techniques for improved ocean imaging and selectivity in pelagic fisheries
    Fassler, S.M.M. ; Scoulding, B.C. ; Burggraaf, D. ; Haan, D. de; Quesson, Benoit ; Sande, Jeroen van de; Beerens, Peter - \ 2015
    IMARES (Report / IMARES C171/15) - 100
    pelagic fishery - marine fisheries - underwater acoustics - fish stocks - bycatch - fishery resources - fishery management - pelagische visserij - zeevisserij - onderwaterakoestiek - visstand - bijvangst - visbestand - visserijbeheer
    Impact Assessment of the Flyshoot fishery in Natura 2000 and MSFD areas of the Dutch continental shelf
    Rijnsdorp, A.D. ; Bos, O.G. ; Slijkerman, D.M.E. - \ 2015
    IJmuiden : IMARES (Report / IMARES C162/15) - 24
    marine fisheries - fishing methods - fishing gear - environmental impact - aquatic ecosystems - north sea - netherlands - zeevisserij - vismethoden - vistuig - milieueffect - aquatische ecosystemen - noordzee - nederland
    North Sea Herring and Pelagic Ecosystem Survey (HERAS) report for R/V "TRIDENS" 22 June - 17 July 2015
    Couperus, A.S. ; Fassler, S.M.M. ; Scoulding, B.C. - \ 2015
    IJmuiden : IMARES (Report / IMARES 15.015) - 30
    herrings - surveys - fish stocks - marine fisheries - acoustic tracking - fishery resources - north sea - haringen - karteringen - visstand - zeevisserij - akoestisch sporen - visbestand - noordzee
    Fisheries displacement effects related to closed areas : a literature review of relevant aspects
    Slijkerman, D.M.E. ; Tamis, J.E. - \ 2015
    Den Helder : IMARES (Report / IMARES C170/15) - 51
    marine fisheries - fishing grounds - displacement - environmental protection - socioeconomics - fishery management - north sea - netherlands - zeevisserij - visgronden - verplaatsing - milieubescherming - sociale economie - visserijbeheer - noordzee - nederland
    VIBEG Monitoring T1 in 2015 - Data Deelrapportage
    Goudswaard, P.C. ; Bakker, A.G. ; Asch, M. van; Smith, S.R. ; Weide, B.E. van der; Brummelhuis, E.B.M. ; Cuperus, J. - \ 2015
    Yerseke : IMARES (Rapport / IMARES C172/15) - 24
    natuurbescherming - zeevisserij - zonering - beschermde gebieden - kustgebieden - bemonsteren - noordzee - nederland - nature conservation - marine fisheries - zoning - reserved areas - coastal areas - sampling - north sea - netherlands
    Het ‘VIBEG (Visserij in Beschermde Gebieden) akkoord’ betreft twee Habitat- en Vogelrichtlijngebieden: ‘Noordzeekustzone’ en ‘Vlakte van de Raan’. Het doel van dit akkoord is om de instandhoudingsdoelen te realiseren voor habitattype H1110B en schelpdieretende vogels in het kader van Natura2000, in combinatie met een ecologisch verantwoorde en duurzame visserij in deze gebieden. Om dit doel te bereiken is voor de Noordzeekustzone in december 2011 een zonering ingesteld met verschillende toegangsregels voor de visserij. Om de mogelijke effecten van deze verschillende visserijregimes op het bodemleven te kunnen vaststellen is in 2013 een onderzoeksprogramma opgestart voor benthische organismen en vissen. Met drie verschillende en elkaar aanvullende technieken: boxcorer, bodemschaaf en garnalennet, is in 2013 een eerste bestandsopname (T0) gemaakt op twee locaties in de Noordzeekustzone: Petten en Ameland. In 2015 is een tweede bestandsopname (T1) gemaakt, wederom op de twee locaties in de Noordzeekustzone: Petten en Ameland. In dit rapport worden de resultaten van de bestandsopname in 2015 gepresenteerd. Een vergelijking tussen de data van 2015 en 2013, zoals die gerapporteerd zijn in Goudswaard et al. (2014), zal in een later stadium plaatsvinden.
    VIP Report Acoustic Data Collection
    Fassler, S.M.M. ; Brunel, T.P.A. ; Couperus, A.S. ; Gastauer, S. ; Burggraaf, D. - \ 2015
    IJmuiden : IMARES (Report / IMARES C178/15) - 121
    herrings - whiting - marine fisheries - fish stocks - fishery resources - fishery management - fishing vessels - acoustic tracking - surveys - haringen - wijting - zeevisserij - visstand - visbestand - visserijbeheer - vissersschepen - akoestisch sporen - karteringen
    De vormgeving van beleid in een Multi-level Governance setting - VIP Rapport : Analyse van bijeenkomsten tussen vissers en EZ over de omstreden aanlandplicht 2013, 2014 en 2015
    Trapman, B.K. ; Kraan, M.L. - \ 2015
    IJmuiden : IMARES (Rapport / IMARES C196/15) - 35
    zeevisserij - discards - vis vangen - visserijbeleid - governance - plichten - wetgeving - europa - marine fisheries - discards - fishing - fishery policy - governance - duties - legislation - europe
    VIP HydroRig II
    Marlen, B. van - \ 2015
    IJmuiden : IMARES (Rapport / IMARES C004/15) - 24
    fishing gear - marine fisheries - fishing methods - plaice - fish catches - netherlands - vistuig - zeevisserij - vismethoden - schol - visvangsten - nederland
    Als vervolg op het VIP-project HydroRig I waarbij een vistuig werd ontwikkeld als alternatief voor de boomkor met manipulatie van de waterstroming in het voortuig van het vistuig is in 2013 en 2014 een nieuwe variant HydroRig II beproefd door de firma Geertruida B.V. Dit vistuig had een breedte van 15 m waarvoor ontheffing was verkregen en wielen die de sloffen vervingen. De praktijkproeven lieten een goed vangstresultaat op schol zien in vergelijking met schepen in de buurt vissend met ca. 10% brandstofbesparing. Een gedetailleerde vangstvergelijking is nodig om ecologische voordelen beter te kwantificeren.
    Pelagic fish discards : technical report on opportunities for silage valorisation
    Rurangwa, E. ; Poelman, M. ; Broeze, J. ; Bosch, Heleen van den - \ 2015
    Yerseke : IMARES (Report / IMARES C197/15) - 30
    pelagic fishery - marine fisheries - discards - fish silage - livestock feeding - bioactive compounds - hydrolysis - feed industry - pelagische visserij - zeevisserij - discards - vissilage - veevoeding - bioactieve verbindingen - hydrolyse - veevoederindustrie
    Over het welzijn van in zee gevangen vis
    Jonge, F.H. de; Boon, N. ; Brauner, M. ; Dakriet, N. ; Kumar Ghosh, A. ; Jansen, J. ; Hamoen, J. ; Kok, J. de; Hürlimann, R. ; Laan, R. ; Marbus, S. ; Merema, P. ; Pijcke, N. ; Rooijen, K. van; Stolwijk, D. ; Vissia, S. ; Vrijenhoek, M. ; Willemsma, A. ; Zaalberg, R. ; Zagenia, F. - \ 2015
    Wageningen : Wetenschapswinkel Wageningen UR (Rapport / Wetenschapswinkel Wageningen UR 322) - 57
    dierenwelzijn - vis - wilde dieren - diergezondheid - visserij - zeevisserij - vismethoden - animal welfare - fish - wild animals - animal health - fisheries - marine fisheries - fishing methods
    De Stichting Vissenbescherming heeft de hulp van de wetenschapswinkel van Wageningen UR ingeroepen. Zij vraagt haar te ondersteunen met onderzoek dat een stap voorwaarts kan betekenen op weg naar een vissenwelzijnskeurmerk voor in het wild gevangen (zee)vis. In totaal 19 studenten (3 studententeams en 2 masterstudenten) deden voor de wetenschapswinkel (literatuur)onderzoek naar a) welzijn van vissen (met name platvis) in relatie tot de visserij en b) maatschappelijke agendering op het gebied van vissenwelzijn. Op grond van een literatuurstudie wordt geconcludeerd dat steeds meer wetenschappelijke argumenten erop wijzen dat ook vissen pijn lijden en emoties kunnen ervaren. Voor diegenen die deze argumenten in twijfel trekken wordt door Elder bepleit het “voorzorgsprincipe” te hanteren, waarbij ernaar gestreefd wordt het risico op pijn en leed bij vissen zoveel mogelijk te voorkomen.
    Teveel tong verspeeld, zoektocht gaat verder: IMARES presenteert tussentijdse resultaten project Netinnovatie kottervisserij (interview met Pieke Molenaar)
    Molenaar, P. - \ 2015
    Visserijnieuws 35 (2015)37. - ISSN 1380-5061 - p. 3 - 3.
    zeevisserij - tong (vis) - innovaties - vistuig - demersale visserij - visserijbeheer - marine fisheries - dover soles - innovations - fishing gear - demersal fisheries - fishery management
    Nederlandse kottervissers halen alles uit de kast om selectiever te vissen en zo met het oog op de aanlandplicht discards te sparen. Maar uit de praktijkproeven blijkt dat scheidingspanelen ook een verlies van zo'n tien procent van de tongvangst te betekenen. De zoektocht gaat verder.
    A food web model of invertebrate subtidal soft-bottom communities Part B: effects of fishery
    Schellekens, T. ; Kooten, T. van - \ 2015
    Yerseke : IMARES (Report / IMARES Wageningen UR C131/15) - 21
    zee-invertebraten - voedselwebben - modellen - aquatische gemeenschappen - zeevisserij - visserijbiologie - visserijbeheer - vistuig - natura 2000 - noordzee - marine invertebrates - food webs - models - aquatic communities - marine fisheries - fishery biology - fishery management - fishing gear - natura 2000 - north sea
    Om visserij in de Natura-2000 gebieden Noordzeekustzone en Vlakte van de Raan zodanig te reguleren, dat zij het behalen van de geformuleerde beleidsdoelen niet in de weg staat, is het VIBEG-akkoord gesloten. Kern van de afspraken vormt een ruimtelijke zonering waarmee wordt bepaald welke visserijtechnieken in welke gebieden wel of niet zijn toegestaan.
    A food web model of invertebrate subtidal soft-bottom communities Part A: model derivation and effects of productivity
    Kooten, T. van; Schellekens, T. - \ 2015
    IJmuiden : IMARES (Report / IMARES Wageningen UR C130/15) - 18
    zee-invertebraten - voedselwebben - modellen - aquatische gemeenschappen - zeevisserij - productiviteit - visserijbiologie - vistuig - natura 2000 - noordzee - marine invertebrates - food webs - models - aquatic communities - marine fisheries - productivity - fishery biology - fishing gear - natura 2000 - north sea
    Om visserij in de Natura-2000 gebieden Noordzeekustzone en Vlakte van de Raan zodanig te reguleren, dat zij het behalen van de geformuleerde beleidsdoelen niet in de weg staat, is het VIBEG-akkoord gesloten. Kern van de afspraken vormt een ruimtelijke zonering waarmee wordt bepaald welke visserijtechnieken in welke gebieden wel of niet zijn toegestaan.
    VIP Valorisatie Reststromen Vis (VRV)
    Poelman, M. ; Kals, J. ; Marlen, B. van; Amerongen, A. van; Bosch, H. van den - \ 2015
    IJmuiden : IMARES Wageningen UR (Rapport / IMARES Wageningen UR C005/15) - 67
    vercommercialisering - visresten - visproducten - zeevisserij - pleuronectiformes - visserijbeleid - kosten-batenanalyse - reststromen - commercialization - fish scrap - fish products - marine fisheries - pleuronectiformes - fishery policy - cost benefit analysis - residual streams
    In het kader van de komende aanlandingsplicht van ondermaatse vis is de sector geïnteresseerd in mogelijkheden om deze aanvoer te laten bijdragen tot het inkomen. De vraag werd gesteld welke producten zouden kunnen worden gemaakt uit visafval (snijafval als koppen en staarten en ingewanden en discards). Monsters van dergelijk visafval werden verzameld aan boord van de FD283 van de firma Geertruida B.V. en geanalyseerd in een verscheidenheid van mogelijke verwerkingsprocessen, zowel aan boord (continue en batch hydrolyse met toegevoegde enzymen) als aan de wal (productie van bioactieve peptiden door hydrolyse, productie van vismeel en visolie) door Food and Bio-based Research (FBR) van Wageningen UR en VFC/Lipromar te Cuxhaven.
    Ecosystem effects of bottom trawl fishing
    Denderen, P.D. van - \ 2015
    Wageningen University. Promotor(en): Adriaan Rijnsdorp, co-promotor(en): Tobias van Kooten. - Wageningen : Wageningen University - ISBN 9789462573468 - 182
    vis vangen - zeevisserij - boomkorvisserij - vismethoden - ecosystemen - milieueffect - visserijbeheer - benthos - soortenrijkdom - mariene ecologie - fishing - marine fisheries - beam trawling - fishing methods - ecosystems - environmental impact - fishery management - benthos - species richness - marine ecology - cum laude
    cum laude graduation
    Het kokkelbestand in de Nederlandse kustwateren in 2015
    Asch, M. van; Ende, D. van den; Brummelhuis, E.B.M. ; Zweeden, C. van; Troost, K. - \ 2015
    IJmuiden : IMARES Wageningen UR (Rapport / IMARES Wageningen UR C111/15) - 44
    kokkels - kustwateren - zeevisserij - visserijbeheer - visbestand - visstand - inventarisaties - nederland - natura 2000 - oosterschelde - westerschelde - waddenzee - clams - coastal water - marine fisheries - fishery management - fishery resources - fish stocks - inventories - netherlands - natura 2000 - eastern scheldt - western scheldt - wadden sea
    Onderzoeksinstituut IMARES heeft in opdracht van het ministerie van EZ in het voorjaar van 2015 het kokkelbestand (Cerastoderma edule) in de Waddenzee, de Oosterschelde en de Westerschelde geïnventariseerd. De inventarisatie wordt jaarlijks uitgevoerd om te kunnen bepalen hoeveel er gevist mag worden en is daarnaast ook van belang voor evaluatie van beheersmaatregelen en effectstudies in het kader van Natura 2000 en de natuurbeschermingswet. De kokkelbestandsopname wordt sinds 1990 uitgevoerd in de Oosterschelde en de Waddenzee, sinds 1992 in de Westerschelde en sinds 1993 in de Voordelta (als onderdeel van de bestandsopnamen van mesheften en halfgeknotte strandschelpen in de Nederlandse kustzone). Doel van deze inventarisaties ten behoeve van de visserij is het bepalen van de voorjaarsbestanden in deze gebieden, op basis waarvan een schatting wordt gemaakt van de oogstbare bestanden in september.
    An exploration of potential effects on fisheries and exploited stocks of a network of marine protected areas in the North Sea
    Kooten, T. van; Deerenberg, C.M. ; Jak, R.G. ; Hal, R. van; Machiels, M.A.M. - \ 2015
    IJmuiden : IMARES Wageningen UR (Report / IMARES Wageningen UR C093/14) - 52
    visserijbeleid - zeevisserij - zeereservaten - noordzee - visserijbeheer - fishery policy - marine fisheries - marine protected areas - north sea - fishery management
    WWF Netherlands has developed a proposal for a network of Marine Protected Areas (MPAs) in the North Sea. Most of the MPAs in this network are already protected under the Natura 2000 framework and/or the Marine Strategy Framework Directive. WWF Netherlands aims to engage with stakeholders and build support for this proposed MPA network. One of the most prominent of these stakeholders is the fishing industry. To provide input for the discussion with stakeholders, the current study investigates potential fishery effects of a total fishery ban in each of the marine protected areas. This represents a hypothetical choice to facilitate comparison with existing scientific literature and calculations of quantity and value of catches and does not reflect a proposal for a total fishery closure of the entire network by either IMARES or WWF Netherlands.
    Vallen en opstaan: update overlevingsprojecten ILVO en IMARES (interview met Karin van der Reijden)
    Reijden, K.J. van der - \ 2015
    Visserijnieuws 35 (2015)17. - ISSN 1380-5061 - p. 5 - 5.
    visserijbeleid - visserijbeheer - discards - zeevisserij - wetgeving - eu regelingen - visserij - mortaliteit - visstand - demersale visserij - dierenwelzijn - diergezondheid - fishery policy - fishery management - discards - marine fisheries - legislation - eu regulations - fisheries - mortality - fish stocks - demersal fisheries - animal welfare - animal health
    De Europese aanlandplicht is een feit. De visserijsector vreest een negatieve invloed op de bestanden door een hogere vissterfte. In de wetgeving is een uitzonderingsmaatregel voor de discardban opgenomen als vis een hoge overlevingskans heeft. Zowel in Nederland als België wordt daarom in de kottervisserij wetenschappelijk onderzocht hoe groot de overlevingskansen van gevangen vis zijn. Karin van der Reijden (WUR - IMARES) en Ruben Theunynck (ILVO) geven inzicht in de stand van zaken.
    Van Discards naar Bijvangst in de Pelagische Visserij
    Goudswaard, P.C. - \ 2015
    Yerseke : IMARES (Rapport / IMARES Wageningen UR C067/15) - 27
    visserij - pelagische visserij - discards - bijvangst - zeevisserij - eu regelingen - visserijbeleid - vangstsamenstelling - vis - fisheries - pelagic fishery - discards - bycatch - marine fisheries - eu regulations - fishery policy - catch composition - fish
    De pelagische diepvriestrawler visserij richt zich volledig op vis die geschikt is voor humane consumptie. Per 1 januari 2015 is de pelagische zeevisserij in de Europese wateren geconfronteerd met een verplichting om alle gevangen soorten waarvan een vangst quotum is vastgesteld, aan land te brengen en niets van deze vissoorten over boord te zetten. Dit is de eerste realisatie van een reeks aanlandverplichtingen van vis in het kader van het Europese Gemeenschappelijke Visserij Beleid. De aanlanding van deze visserij zal als gevolg van de aanlandplicht veranderen. In dit deelrapport wordt ingegaan op (i) de omvang en samenstelling van de hoeveelheid vis die onder het voormalige systeem als discards beschouwd wordt en (ii) in de hoeveelheid vis die als basis van mogelijke verwerkingsstappen voor valorisatie gebruikt kunnen worden. Daarnaast wordt een verwachting geschetst van de te verwachten hoeveelheid discards die aangeland moeten gaan worden onder de aanlandverplichting die vanaf 1 januari 2015 van kracht is. Dit geeft inzicht in de mogelijkheden voor industriële benutting van de “discards” die een waarde verhoging ten opzichte van laagwaardige verwerking tot vismeel meebrengt.
    Wettelijk Onderzoek Taken WOT-05 Visserijonderzoek: Beknopte jaarraaportage 2014
    Verver, S.W. - \ 2015
    IJmuiden : Centrum voor Visserijonderzoek (CVO rapport 15.007)
    visserijbeheer - visserijbeleid - visbestand - zeevisserij - aquacultuur - beleidsondersteuning - jaarverslagen - nederlandse wateren - economische evaluatie - fishery management - fishery policy - fishery resources - marine fisheries - aquaculture - policy support - annual reports - dutch waters - economic evaluation
    Deze jaarrapportage informeert het Ministerie van Economisch Zaken (EZ) over het onderzoek dat in 2014 is uitgevoerd binnen het programma WOT-05 Visserijonderzoek van DLO. In dit programma worden wettelijke onderzoekstaken uitgevoerd die betrekking hebben op het beheer van de visserij op zee, in Nederlandse kust- en binnenwateren en in de aquacultuur. De tabellen met financiële informatie in deze rapportage zijn een samenvatting van een uitgebreidere rapportage zoals deze afzonderlijk aan EZ verstrekt wordt door DLO.
    Wettelijk Onderzoek Taken WOT-05 Visserijonderzoek: jaarverslag 2014
    Verver, S.W. - \ 2015
    IJmuiden : Centrum voor Visserijonderzoek (CVO rapport 15.006) - 101
    visserijbeheer - visbestand - aquacultuur - zeevisserij - visserijbeleid - nederlandse wateren - jaarverslagen - beleidsondersteuning - fishery management - fishery resources - aquaculture - marine fisheries - fishery policy - dutch waters - annual reports - policy support
    The programme WOT-05 Fishery Research is carrying out statutory research tasks related to the management of the fishery and aquaculture in the Netherlands. The programme is developed in consultation with the Ministry of Economic Affairs (EZ). This report is a technical report and summarises the progress made in carrying out the work plan of 2014. Fisheries policy makers and managers are dependent on up-to-date information. The aim of this programme is to contribute to the collection of essential data needed for the management of fisheries, fish stocks and aquaculture through sampling programmes in as well marine and inshore areas.
    Methods for integrated use of fisheries research survey information in understanding marine fish population ecology and better management advice : improving methods for evaluation of research survey information under consideration of survey fish detection and catch efficiency
    Nielsen, J.R. - \ 2015
    Wageningen University. Promotor(en): Adriaan Rijnsdorp. - Wageningen : Wageningen University - ISBN 9789462572553 - 187
    zeevisserij - onderzoek - karteringen - visserijbeheer - zeevissen - populatie-ecologie - evaluatie - methodologie - visvangsten - visbestand - visserijbiologie - marine fisheries - research - surveys - fishery management - marine fishes - population ecology - evaluation - methodology - fish catches - fishery resources - fishery biology

    Summary

    The thesis developed and improved methods for the integrated analysis of different types of fishery independent research surveys (trawl surveys, acoustic surveys, hydrographical surveys, and gillnet surveys) to study the distribution, density, abundance, migration and biological population dynamic parameters of marine fish species. The topics in the thesis addressed different combinations of trawl, hydro-acoustic, gillnet, and hydrographical data and application of different survey data analysis methods under consideration of factors influencing the survey catch and detection efficiency. Each topic was investigated in one of more case studies.

    One thesis topic has been to provide more precise estimates of fish distribution and density patterns from survey data (Chapter 2). The 1st case study applied advanced statistical methods to Baltic trawl data and hydro-acoustic survey data in combination with survey sampled hydrographical data to estimate distri­bution and density patterns of juvenile 0-group Baltic cod. These patterns were largely unknown. In the 2nd case study new methodology was developed for analyzing trawl research survey data for Baltic cod and whiting including the corre­la­tion in distribution and density according to space, time, size, and species. The more precise density estimates improve the knowledge of the stock-recruitment relationship of Baltic cod and can improve the Baltic multi-species stock assessment. Furthermore, it will enable more precise marine management and spatial planning involving fish stocks and fisheries in the Baltic Sea. In context of Baltic cod stock assessment, the 3rd case study developed a new method for inter-calibration of trawl survey CPUE data by fish size group exemplified by Baltic cod (and flounder) where the concept of disturbance by one trawl haul in relation to the next have been developed and quantified when calibrating new research survey trawl gears with the former ones. These results have been based on introduction of a new international ICES BITS trawl research survey design.

    A second topic was to improve and develop hydroacoustic research survey methods for more precise detection and discrimination of fish species according to fish size and orientation in the water (Chapter 3). Here, the 4th case study focused on more precise acoustic target strength estimation of juvenile cod, while the 5th case study has focused on acoustic discrimination of juvenile gadoid fish in particular juvenile Baltic cod. This enables more efficient research survey estimation of juvenile cod (gadoid) density patterns to be used in stock recruitment estimates and stock assessment.

    The third topic was to estimate more precisely fish mortality, maturity, and growth parameters for small forage fish species using research survey information (Chapter 4). Associated to this, the 5th case study analysed these population dynamic parameters using trawl survey data taking into account spatial variation. This study provided more precise estimates and deeper understanding of Norway pout mortality, maturity, and growth dynamics. The more precise population dynamic parameters have been implemented in and improved the North Sea Norway pout stock assessment, management advice, management, and long term management plan evaluations.

    The fourth topic was to develop methodology to integrate hydroacoustic, gillnet, and hydro­gra­phi­cal research survey data to investigate pelagic fish migration patterns (Chapter 5). The methods were applied in the 6th case study to evaluate Western Baltic herring feeding and spawning migra­tion based on distribution and density estimates in a narrow over-wintering area of the stock. The more precise information on migration patterns gives better possibility for acoustic monitoring of the full stock abundance in different areas and seasons og the year to be used in stock assessment and marine spatial planning. Also, it increases knowledge on biological interactions and mixing with other stocks and species.  

    In the final synthesis Chapter 6, the thesis reviews relevant analysis methods of research survey data and underlying data distributions, survey design and stratification, trawl survey inter-calibration and standardization, as well as estimation procedures and data processing methods in context of the obtained results and methods developed in the thesis. This is done with focus on survey precision and uncertainty (bias, sources of errors) for trawl and acoustic surveys and factors affecting it.

     

     

     

     

    Dioxines en PCB's in Chinese wolhandkrab
    Kotterman, M.J.J. ; Leeuwen, S.P.J. van; Hoogenboom, L.A.P. - \ 2014
    IJmuiden : IMARES (Rapport / IMARES C120/14) - 36
    krabben (schaaldieren) - dioxinen - polychloorbifenylen - besmetting - toxinen - zeevisserij - crabs - dioxins - polychlorinated biphenyls - contamination - toxins - marine fisheries
    Factsheet: Pulsvisserij
    Quirijns, F.J. ; Turenhout, M.N.J. ; Paijmans, A.J. ; Taal, K. - \ 2014
    pulsvisserij - visserij-ecologie - discards - visvangsten - economische haalbaarheid - vismethoden - boomkorvisserij - zeevisserij - vangstsamenstelling - pulse trawling - fisheries ecology - discards - fish catches - economic viability - fishing methods - beam trawling - marine fisheries - catch composition
    De pulstechniek is relatief nieuw en roept veel vragen op over de mate van duurzaamheid en economische haalbaarheid. Daarom is er in de afgelopen decennia veel onderzoek gedaan naar deze visserijtechniek. Deze factsheet bevat de laatste gegevens over vangsten, discards, ecosysteem-effecten en economische haalbaarheid bij gebruik van puls in de platvisvisserij.
    Wettelijke Onderzoek Taken WOT-05 Visserijonderzoek: Werksafspraken en werkplan 2015
    Verver, S.W. - \ 2014
    IJmuiden : Centrum voor Visserijonderzoek (CVO rapport 14.006)
    visserijbeleid - visserij - zeevisserij - kustwateren - aquacultuur - binnenwateren - visserijbeheer - visstand - bijvangst - statistiek - monitoring - onderzoek - duurzaamheid (sustainability) - recreatieactiviteiten - palingen - schaaldieren - fishery policy - fisheries - marine fisheries - coastal water - aquaculture - inland waters - fishery management - fish stocks - bycatch - statistics - monitoring - research - sustainability - recreational activities - eels - shellfish
    Dit rapport beschrijft het werkplan voor 2015 van cluster WOT-05 Visserijonderzoek van Wageningen UR. Wageningen UR voert voor het Ministerie van Economische Zaken (EZ) een aantal programma’s met Wettelijke Onderzoek Taken (WOT) uit. Binnen WOT-05 worden Wettelijke Onderzoek Taken uitgevoerd die betrekking hebben op het beheer van de visserij op zee, in Nederlandse kust- en binnenwateren en de aquacultuur. Het werkplan is een uitwerking van de Uitvoeringsovereenkomst tussen het Ministerie van EZ en de Stichting Dienst Landbouwkundig Onderzoek (DLO), onderdeel van Wageningen UR, voor diensten vanwege wettelijke taken op het terrein van visserijonderzoek voor de periode 2011-2015. Bij deze uitvoerings-overeenkomst zijn voor deze periode werkafspraken gemaakt welke de basis vormen voor de jaarlijkse werkplannen. Daarnaast zijn in deze overeenkomst afspraken gemaakt over de KennisBasis (KBWOT) die specifiek aan dit programma is gekoppeld.
    Vangsten en discards van de pulsvissers GO48 & SL42
    Reijden, K. van der; Rasenberg, M.M.M. - \ 2014
    IJmuiden : IMARES (Rapport / IMARES 14.IMA0354) - 21
    visserij - zeevisserij - zeevissen - samenstelling - pulsvisserij - discards - monitoren - vangstsamenstelling - fisheries - marine fisheries - marine fishes - composition - pulse trawling - discards - monitors - catch composition
    C. Tanis Jaczn. en Zonen C.V. (GO48) en vof Visserijbedrijf C. en J. Brinkman (SL42) zijn in 2012 overgeschakeld naar de pulsvisserij. Vanuit de regeling ‘Duurzame Ontwikkeling Visserijgebieden’ is subsidie toegekend voor de innovatie van de pulskortuigen van beide schepen. Binnen dit project was afgesproken om een document op te leveren met de discard gegevens van beide schepen, deze notitie. Dit betroffen gegevens van twee rnemersreizen en gegevens van twee monitoringsprojecten, afkomstig uit andere projecten. Zo namen beide schepen deel aan het VIP project ‘Praktijknetwerk Netinnovatie’, waaronder de waarnemersreizen vielen. Daarnaast hebben beide schepen deelgenomen aan een monitorprogramma van IMARES; de SL42 nam deel aan de pulskormonitoring, de GO48 aan de discardmonitoring.
    Notitie over vangsten en discards van de pulsvisserij van de ARM25 / ARM33 / TH6
    Rasenberg, M.M.M. - \ 2014
    IJmuiden : IMARES (Rapport / IMARES 14.IMA0158) - 16
    zeevisserij - visserij - pulsvisserij - monitoring - vangstsamenstelling - benthos - marine fisheries - fisheries - pulse trawling - monitoring - catch composition - benthos
    In 2011 en 2012 zijn Vof Zeevisserijbedrijf C. Caljouw en Zn. (ARM25), Visserijbedrijf Van Belzen vof (ARM33) en Zeevisserijbedrijf Johanna Cornelia K.J. Bout en Zn. cv. (TH6) overgeschakeld naar de pulsvisserij. De drie chepen hebben deelgenomen aan de pulskormonitoring en in dit onderzoek gegevens verzameld over de vangsten en discards van de pulsvisserij. De schepen hebben gedurende het programma wekelijks één mand vangst van én trek op een vaste dag en tijd bemonsterd. De mand vangst werd uitgezocht op schol, tong, kabeljauw, en overige vis waarbij onderscheid werd gemaakt tussen maats en ondermaats en op benthos en debris.
    Governance innovation networks for sustainable tuna
    Miller, A.M.M. - \ 2014
    Wageningen University. Promotor(en): Arthur Mol, co-promotor(en): Simon Bush. - Wageningen : Wageningen University - ISBN 9789462570252 - 194
    tonijn - zeevisserij - governance - duurzaamheid (sustainability) - regelingen - netwerken - innovaties - milieubeleid - tuna - marine fisheries - governance - sustainability - regulations - networks - innovations - environmental policy

    Governance Innovation Networks for Sustainable Tuna

    Alice M.M. Miller

    Tuna fisheries are among the most highly capitalised and valuable fisheries in the world and their exploitation will continue for the foreseeable future. This means the sustainability of tuna stocks is a pressing global issue that has received attention from a wide range of societal actors. The analysis presented in this thesis investigates governance innovation networks to understand how interdependent governance arrangements for production and consumption in the tuna global production networks, steer and shape processes of sustainability innovation.

    The question this research seeks to answer is how do different market- and state-led governance innovations advance the governance of sustainable tuna? Using the analytical lens of global production networks, four different governance innovations for sustainability in tuna fisheries in the Western and Central Pacific Ocean, targeting European and North American markets are examined. More specifically: state-led governance innovations in the West and Central Pacific Ocean both through regional bodies and through the interaction between the EU and the Pacific Islands countries; and market-led innovations through the implementation of private standards for certifying tuna fisheries and the firm-NGO development and implementation of consumer-facing traceability systems.

    The cases in this thesis indicate that the state- and market-led distinction is inadequate for understanding sustainability governance in the tuna global production network. Instead, different efforts to both frame and deal with issues surrounding sustainability in the tuna global production network sees actors produce innovative instruments to influence production and consumption practices and that these instruments interact with each other and with different actors to form actor-instrument arrangements. This interaction leads to a reclassification of actor roles away from their assignation as standard state, market and NGO and in turn, this reclassification presents us with the need to form different concepts of power. Therefore, through governance innovation networks we can understand how the interaction between actors and instruments is reconfiguring global production networks when sustainability moves to the fore.

    Niet perfect, wel bruikbaar: de discardatlas voor de Noordzee komt eraan (interview met Martine Pastoors en Floor Quirijns)
    Pastoors, M.A. ; Quirijns, F.J. - \ 2014
    Visserijnieuws 34 (2014)23. - ISSN 1380-5061 - p. 4 - 4.
    discards - visserijbeheer - zeevisserij - noordzee - visserij - visvangsten - discards - fishery management - marine fisheries - north sea - fisheries - fish catches
    Over hoeveel discards hebben we het nu eigenlijk? Met de aanlandplicht in zicht is die vraag prangerder dan ooit. In 2013 besloten de landen rond de Noordzee om te werken aan een discardatlas voor de Noordzee, met daarin informatie over de discards per visserij en per gebied. Martin Pastoors van de PFA/Redersvereniging en Floor Quirijns van IMARES vertellen over de mogelijkheden en onmogelijkheden van de binnenkort te verschijnen discardatlas.
    Ontwikkeling zeebodemintegriteit op het Friese Front en de Centrale Oestergronden in relatie tot bodemberoerende visserij: Verslag expert workshop
    Jongbloed, R.H. ; Slijkerman, D.M.E. ; Witbaard, R. ; Lavaleye, M.S.S. - \ 2013
    Den Helder : IMARES (Rapport / IMARES Wageningen UR C212/13) - 55
    visserij - zeevisserij - mariene ecologie - bodemecologie - noordzee - kennisoverdracht - inventarisaties - fisheries - marine fisheries - marine ecology - soil ecology - north sea - knowledge transfer - inventories
    Het bodemecosysteem van het diepe, slibrijke, noordelijke deel van het NCP wordt momenteel nog niet beschermd. Dit type ecosysteem is aanwezig in de gebieden het Friese Front en de Centrale Oestergronden. Deze gebieden zijn door het Kabinet aangemerkt als zoekgebieden voor ruimtelijke beschermingsmaatregelen. In dit rapport richten we ons op de vraag: - Wat ontwikkelt zich aan habitatkarakteristieken, en vervolgens aan soorten, als je de gebieden sluit voor bodemberoerende visserij? Deze vraag is uitgediept middels een workshop met tien experts van zes Nederlandse organisaties met expertise op het gebied van o.a. mariene ecologie, geologie, morfologie, processen, taxonomie, Noordzee benthos, en impacts van menselijke activiteiten, waaronder visserij.
    Sea@shore: informational governance in marine spatial conflicts at the North Sea
    Toonen, H.M. - \ 2013
    Wageningen University. Promotor(en): Arthur Mol; Jan van Tatenhove; Han Lindeboom. - Wageningen UR : Wageningen UR - ISBN 9789461737748 - 199
    aquatische ecosystemen - mariene gebieden - natuurbescherming - zeereservaten - governance - noordzee - windenergie - zeevisserij - milieubeleid - aquatic ecosystems - marine areas - nature conservation - marine protected areas - governance - north sea - wind power - marine fisheries - environmental policy

    Oceans and seas seem to be an empty space and untouched wilderness, but are in fact heavily used and exploited by different economic activities which have, to greater or lesser extent, environmental impacts. Attention for marine environmental challenges has grown, and is nowadays captured by views on ecosystem-based management. This builds on the notion that the way forward in marine ecosystem protection is an integrated approach that is place- or area-based (so-called spatial turn) and should use the best available scientific information. This research focuses on this spatial turn in marine governance at the North Sea, one of the busiest seas in the world. More specifically, the emphasis on the informational governance of spatial tensions between nature conservation and economic activities at the North Sea.

    Informational governance points to the growing centrality of informational processes in decision-making around environmental challenges. Information is seen as an indispensable resource to use in resolving such challenges and serves as steering tool in governing sustainability. Information provision through all kind of (online) media means is deliberately aimed at influencing decision-making and fostering change of behaviour. In the marine context, informational governance seems to be a new and promising mode of governance. Facilitated by information and communication technologies, information can connect spatially distant environmental issues to people’s daily lives. However, information is not seen as an unproblematic and neutral object, it is at the centre of struggles and debates in decision-making on resolving spatial and environmental challenges at sea.

    This study analyzes how public and private actors through informational governance (try to) resolve spatial conflicts between economic activities and nature conservation at the North Sea, in order to better understand the centripetal force of information in marine governance. Three research questions are guiding the research:

    How can the centrality of information in the spatial turn in marine governance be conceptualized and analyzed? Which actors are involved in informational governance on marine ecosystem protection and use at the North Sea, and how do they (inter-) act in informational processes? How does informational governance contribute to the solving of spatial conflicts between economic activities and nature conservation at the North Sea?

    Chapter 2 gives an account of the research methodology that underpins the research. It explains that the study draws on a non-radical constructivist and critical realist perspective, and presents the research design used in the study: a qualitative case study approach. The selection of the cases has been based on two different rationales. Two cases were selected as they highlight the role of three main actor groups in informational governance at sea. Two other cases explore informational processes in governance arrangements with regard to a specific spatial conflict between marine ecosystem conservation and use(fisheries and offshore wind power development) . In the study, triangulated data gathering served to strengthen the validity and reliability of the research. The mix of methods employed included document review of research reports, policy documents and online information; semi-structured interviews; and participatory observation in several meetings and conferences. In data analysis, an iterative approach following the theoretical propositions of the research was used.

    In Chapter 3, the marine scaping framework is presented to analyse informational governance on marine ecosystem protection and use. Marine scaping through information follows the morphogenetic approach and combines a focus on conditions structuring informational processes with an agency-based approach. The framework distinguishes three scapes that together form the structure-side: seascape, humanscape and mindscape. Seascape represents the connection between the biophysical specifics of the marine ecosystem and the material features of economic activities that are emplaced in this ecosystem. Humanscape points to human organization in social, political and economic terms. Mindscape brings in the ideational dimension, and refers to discourses, ideas, norms, values and perceptions. In the interplay of humanscape with seascape and mindscape, the connection with agency is made, pointing to the initiatives and interactions between actors who, by means of information, strive for sustainability at the North Sea. To assess whether conditions have changed over time, so- called elaboration is added to the framework. In marine governance, the explicit aim is to strive for a balance between ecosystem protection and use, hence to foster elaboration.

    Chapter 3 illustrates the application of the marine scaping framework by a case study about informational initiatives of eNGO officials who want to push the development of a network of Marine Protected Areas (MPAs) at the North Sea forward, in order to achieve “ecological coherence” in marine conservation on the North Sea. It is indicated how and why officials from environmental non-gouvernmental organizations (eNGOs) carried out extensive science-based studies to inform policy-making. This information remains however footloose, because there was no institutional setting where the specific need for a MPA network was (high) on the agenda, and as such, eNGOs had no opportunity to tap their reports into existing informational processes. At the same time, this case study shows how eNGOs build up their so-called “informational capital”.

    The case study presented in Chapter 4 provides a historical understanding of informational interactions between science and policy in the Dutch MPA site selection. By establishing MPAs, nature conservation gains literally a place on the North Sea map. Following international regulations and treaties, North Sea countries are obliged to take the leading role in the designation process, and to use scientific criteria only, based on biological and ecological information. The chapter shows that information about vulnerable and pristine habitats and sea life that needs to be protected was merely lacking or contested. It becomes evident that ecological , socio-economic and political considerations cannot be easily separated. Scientists and policy-makers dealt with the entanglement of interests by sharing tasks in the informational processes, being both information providers and users. It is found that especially in cases of uncertainties and data gaps, judgment by scientists is best characterized as expert judgment and sometimes even gut feeling. However, it is also highlighted that it is necessary to keep science as impartial as possible, and to overtly communicate what and whose information is used.

    Chapter 5 analyses the role of information in incorporating the habitat impact of bottom touching gear in the certification scheme of the Marine Stewardship Council (MSC). This represents a spatial conflict between one of the oldest maritime activities at the North Sea, (plaice) fisheries, and marine conservation. The global MSC labeling program is probably the most famous example of informational governance on marine ecosystem protection and use, as it is almost 20 years old. It fits in neatly with the ideas of informational governance: scientific information to assess the environmental performance of a fishery clash with information derived from the fishery itself and stakeholders. And at the same time, information about the fisheries' performance (through the logo on a fish product) is brought to consumers who in turn can reward sustainable fisheries through their buying power. This case study indicates how eNGOs use informational capital in the informational struggles . This role became especially evident during the assessment of the first North Sea plaice fishery, when WWF started to negotiate information with fishermen beyond the formal MSC assessment procedure in order to creating so-called ‘no take-zones’. The eNGO made sure that informal interactions were not totally disconnected from the assessment process. According to this case study, the two fisheries who agreed on the spatial measure also tried to get most out of the additional spatial measure that became part of their certification. They took the spatial measure up in their message towards (potential) clients, stating their fisheries go even beyond the high sustainability standards of MSC.

    The case study in Chapter 6 concerns informational processes related to the ecological impacts of an economic newcomer at the North Sea, that is offshore wind energy. The chapter highlights how the sustainability promise of this renewable source appears to be ‘dark green’: offshore wind farms (OWFs) contribute to the mitigation of greenhouse gas emissions and to the protection of certain marine life (benthos, fish and some bird species). Remarkably, the ecological differentiation towards offshore wind power remains unexploited. Powerful actors related to this pro-wind discourse, such as the wind sector and large eNGOs, are hesitant to use the dark green message of offshore wind power. In onshore wind debates, their emphasis is on the dominant ‘pro-wind’ discourse about combating climate change which leaves no room for (nuanced) spatial and ecological concerns. It is however stated that including the ecological merits of OWFs in an (existing) informational governance design would not be very complicated, and allows actors to commonly strive for further differentiation in the European electricity market.

    The last chapter recapitulates the general findings of the research. The conclusions suggest that a broad array of actors is involved in informational processes that relate to marine governance and push for more sustainability at the North Sea. These actors can take up five distinctive roles in informational processes, that of information negotiator, information authority, information manager, information verifier and information mediator. This role division might be established in a formal way, although often there is room for actors to take up different roles, sometimes only temporally or informally. The conclusions also point to the theoretical contribution of this research to the theoretical development of informational governance, most notably the lessons learnt from its application to the marine context. The methodological reflections indicate the generalizability of the findings, which are in this research linked to the development of the marine scaping framework and the empirically informed distinction between the five roles of actors in informational governance. Finally, the concluding chapter highlights opportunities for future research, such as studies of informational governance related to other economic activities at the North Sea or in other parts of the world.


    Oceans and seas seem to be an empty space and untouched wilderness, but are in fact heavily used and exploited by different economic activities which have, to greater or lesser extent, environmental impacts. Attention for marine environmental challenges has grown, and is nowadays captured by views on ecosystem-based management. This builds on the notion that the way forward in marine ecosystem protection is an integrated approach that is place- or area-based (so-called spatial turn) and should use the best available scientific information. This research focuses on this spatial turn in marine governance at the North Sea, one of the busiest seas in the world. More specifically, the emphasis on the informational governance of spatial tensions between nature conservation and economic activities at the North Sea.

    Informational governance points to the growing centrality of informational processes in decision-making around environmental challenges. Information is seen as an indispensable resource to use in resolving such challenges and serves as steering tool in governing sustainability. Information provision through all kind of (online) media means is deliberately aimed at influencing decision-making and fostering change of behaviour. In the marine context, informational governance seems to be a new and promising mode of governance. Facilitated by information and communication technologies, information can connect spatially distant environmental issues to people’s daily lives. However, information is not seen as an unproblematic and neutral object, it is at the centre of struggles and debates in decision-making on resolving spatial and environmental challenges at sea.

    This study analyzes how public and private actors through informational governance (try to) resolve spatial conflicts between economic activities and nature conservation at the North Sea, in order to better understand the centripetal force of information in marine governance. Three research questions are guiding the research:

    How can the centrality of information in the spatial turn in marine governance be conceptualized and analyzed? Which actors are involved in informational governance on marine ecosystem protection and use at the North Sea, and how do they (inter-) act in informational processes? How does informational governance contribute to the solving of spatial conflicts between economic activities and nature conservation at the North Sea?

    Chapter 2 gives an account of the research methodology that underpins the research. It explains that the study draws on a non-radical constructivist and critical realist perspective, and presents the research design used in the study: a qualitative case study approach. The selection of the cases has been based on two different rationales. Two cases were selected as they highlight the role of three main actor groups in informational governance at sea. Two other cases explore informational processes in governance arrangements with regard to a specific spatial conflict between marine ecosystem conservation and use(fisheries and offshore wind power development) . In the study, triangulated data gathering served to strengthen the validity and reliability of the research. The mix of methods employed included document review of research reports, policy documents and online information; semi-structured interviews; and participatory observation in several meetings and conferences. In data analysis, an iterative approach following the theoretical propositions of the research was used.

    In Chapter 3, the marine scaping framework is presented to analyse informational governance on marine ecosystem protection and use. Marine scaping through information follows the morphogenetic approach and combines a focus on conditions structuring informational processes with an agency-based approach. The framework distinguishes three scapes that together form the structure-side: seascape, humanscape and mindscape. Seascape represents the connection between the biophysical specifics of the marine ecosystem and the material features of economic activities that are emplaced in this ecosystem. Humanscape points to human organization in social, political and economic terms. Mindscape brings in the ideational dimension, and refers to discourses, ideas, norms, values and perceptions. In the interplay of humanscape with seascape and mindscape, the connection with agency is made, pointing to the initiatives and interactions between actors who, by means of information, strive for sustainability at the North Sea. To assess whether conditions have changed over time, so- called elaboration is added to the framework. In marine governance, the explicit aim is to strive for a balance between ecosystem protection and use, hence to foster elaboration.

    Chapter 3 illustrates the application of the marine scaping framework by a case study about informational initiatives of eNGO officials who want to push the development of a network of Marine Protected Areas (MPAs) at the North Sea forward, in order to achieve “ecological coherence” in marine conservation on the North Sea. It is indicated how and why officials from environmental non-gouvernmental organizations (eNGOs) carried out extensive science-based studies to inform policy-making. This information remains however footloose, because there was no institutional setting where the specific need for a MPA network was (high) on the agenda, and as such, eNGOs had no opportunity to tap their reports into existing informational processes. At the same time, this case study shows how eNGOs build up their so-called “informational capital”.

    The case study presented in Chapter 4 provides a historical understanding of informational interactions between science and policy in the Dutch MPA site selection. By establishing MPAs, nature conservation gains literally a place on the North Sea map. Following international regulations and treaties, North Sea countries are obliged to take the leading role in the designation process, and to use scientific criteria only, based on biological and ecological information. The chapter shows that information about vulnerable and pristine habitats and sea life that needs to be protected was merely lacking or contested. It becomes evident that ecological , socio-economic and political considerations cannot be easily separated. Scientists and policy-makers dealt with the entanglement of interests by sharing tasks in the informational processes, being both information providers and users. It is found that especially in cases of uncertainties and data gaps, judgment by scientists is best characterized as expert judgment and sometimes even gut feeling. However, it is also highlighted that it is necessary to keep science as impartial as possible, and to overtly communicate what and whose information is used.

    Chapter 5 analyses the role of information in incorporating the habitat impact of bottom touching gear in the certification scheme of the Marine Stewardship Council (MSC). This represents a spatial conflict between one of the oldest maritime activities at the North Sea, (plaice) fisheries, and marine conservation. The global MSC labeling program is probably the most famous example of informational governance on marine ecosystem protection and use, as it is almost 20 years old. It fits in neatly with the ideas of informational governance: scientific information to assess the environmental performance of a fishery clash with information derived from the fishery itself and stakeholders. And at the same time, information about the fisheries' performance (through the logo on a fish product) is brought to consumers who in turn can reward sustainable fisheries through their buying power. This case study indicates how eNGOs use informational capital in the informational struggles . This role became especially evident during the assessment of the first North Sea plaice fishery, when WWF started to negotiate information with fishermen beyond the formal MSC assessment procedure in order to creating so-called ‘no take-zones’. The eNGO made sure that informal interactions were not totally disconnected from the assessment process. According to this case study, the two fisheries who agreed on the spatial measure also tried to get most out of the additional spatial measure that became part of their certification. They took the spatial measure up in their message towards (potential) clients, stating their fisheries go even beyond the high sustainability standards of MSC.

    The case study in Chapter 6 concerns informational processes related to the ecological impacts of an economic newcomer at the North Sea, that is offshore wind energy. The chapter highlights how the sustainability promise of this renewable source appears to be ‘dark green’: offshore wind farms (OWFs) contribute to the mitigation of greenhouse gas emissions and to the protection of certain marine life (benthos, fish and some bird species). Remarkably, the ecological differentiation towards offshore wind power remains unexploited. Powerful actors related to this pro-wind discourse, such as the wind sector and large eNGOs, are hesitant to use the dark green message of offshore wind power. In onshore wind debates, their emphasis is on the dominant ‘pro-wind’ discourse about combating climate change which leaves no room for (nuanced) spatial and ecological concerns. It is however stated that including the ecological merits of OWFs in an (existing) informational governance design would not be very complicated, and allows actors to commonly strive for further differentiation in the European electricity market.

    The last chapter recapitulates the general findings of the research. The conclusions suggest that a broad array of actors is involved in informational processes that relate to marine governance and push for more sustainability at the North Sea. These actors can take up five distinctive roles in informational processes, that of information negotiator, information authority, information manager, information verifier and information mediator. This role division might be established in a formal way, although often there is room for actors to take up different roles, sometimes only temporally or informally. The conclusions also point to the theoretical contribution of this research to the theoretical development of informational governance, most notably the lessons learnt from its application to the marine context. The methodological reflections indicate the generalizability of the findings, which are in this research linked to the development of the marine scaping framework and the empirically informed distinction between the five roles of actors in informational governance. Finally, the concluding chapter highlights opportunities for future research, such as studies of informational governance related to other economic activities at the North Sea or in other parts of the world.

    Scheidingspaneel in platvisvisserij toont hoopvolle resultaten: pulskotter met paneel kan 65 procent minder discards vangen dan bokker met wekkerketting (interview met Bob van Marlen)
    Marlen, B. van - \ 2013
    Visserijnieuws 33 (2013)45. - ISSN 1380-5061 - p. 7 - 7.
    boomkorvisserij - pulsvisserij - zeevisserij - pleuronectiformes - discards - beam trawling - pulse trawling - marine fisheries - pleuronectiformes - discards
    Het aanbrengen van scheidingspanelen in boomkor- en pulskornetten biedt hoopvolle resultaten om de hoeveelheid discards te reduceren. Dat blijkt uit praktijkonderzoek afgelopen zomer op de TX 68 en UK 45. Vissers zelf spraken over discardreducties tot dertig procent. IMARES heeft de wetenschappelijke rapportage bijna afgerond en komt op verschillen van 15 procent bij de Texelse pulsvisser en 25 procent bij de Urker bokker. Een verslag van projectmanager Bob van Marlen (IMARES) in samenspraak met de schippers Cor Daalder, Pieter Aris van der Vis en Jelle Hakvoort. In vergelijking tot een bokker met wekkerketting noemt Van Marlen een reductie van circa 65 procent mogelijk met een pulskotter met panelen.
    Noordzeevissers verkopen hun vis zelf via internet : VersvandeVisser.nl
    Eijk, H. van; Wubben, R. ; Taal, C. - \ 2013
    Utrecht : InnovatieNetwerk (Rapport / Innovatienetwerk 13.2.318) - ISBN 9789050595025 - 71
    vis - markten - zeevisserij - zeevissen - handel - internet - logistiek - fish - markets - marine fisheries - marine fishes - trade - internet - logistics
    Vissers kunnen via internet, met een eigen ‘webmarket’, een aanzienlijk hogere omzet en een hogere marge per kilogram vis realiseren in vergelijking met de bestaande verkoopmethode via de visafslag. Met deze nieuwe afzetmogelijkheid in de keten voeren de vissers zelf de regie. De directe relatie met de klant die zo wordt gecreëerd, stelt de visser in staat om meer klantgericht te gaan opereren. De in dit rapport kort uitgewerkte businesscase, webmarket “VersvandeVisser.nl”, verschaft Nederlandse Noordzeevissers inzicht 2 in de rollen, kosten en opbrengsten per ketenschakel. Hiermee is inzichtelijk gemaakt waar mogelijkheden voor vissers liggen om zelf binnen de keten een grotere rol te spelen in het vermarkten van duurzaam gevangen vis, waardoor betere opbrengsten kunnen worden gerealiseerd. Door aan te sluiten op een al opgezette webmarkettool, ’VersvandeKweker.nl’, zou in samenwerking met de visafslag in Scheveningen (UFA, United Fish Auctions) en andere partijen, een pilot moeten worden gestart om rechtstreeks (via internet) verse vis en garnalen aan consumenten en zakelijke klanten te verkopen.
    Nederlanders discussiëren mee met Britten : grootschalige brainstormsessie in Brixham over duurzame visserijtoekomst
    Taal, C. - \ 2013
    Visserijnieuws 33 (2013)32. - ISSN 1380-5061 - p. 6 - 7.
    visserij - zeevisserij - duurzaamheid (sustainability) - kennisoverdracht - kennis - groot-brittannië - fisheries - marine fisheries - sustainability - knowledge transfer - knowledge - great britain
    Wat moet de Britse visserij doen en laten voor een duurzame visserijtoekomst? Het Britse Seafish organiseerde over deze vraag vorige maand in samenwerking met de Prince Charles Charity Foundation en de International Sustainability Unit (ISU) een nationale brainstormsessie. Vanuit Nederland waren Kees Taal (LEI, Wageningen UR), Pieter Louwe van Slooten (UK 153 en UK 148), Louwe de Boer (Ekofish Group) en Marieke Verweij (Prosea) uitgenodigd om mee te discussiëren. Taal schreef een verslag.
    Pilot:"collecting Marine ligtter during regular fish surveys
    Hal, R. van; Vries, M. de - \ 2013
    IJmuiden : IMARES (Report / IMARES Wageningen UR C112/13) - 30
    vaste afvalstoffen - zeevisserij - visserij - inventarisaties - noordzee - solid wastes - marine fisheries - fisheries - inventories - north sea
    This report presents the results of a pilot to monitor marine litter on the sea-floor using regular bottom trawl fish surveys. In the last years registration of marine litter became common practice on some international bottom trawl fish surveys, however it was implemented differently on the participating international vessels. The pilot study gave special attention to the registration of litter caught during the Dutch IBTS Q1 in 2013. This meant that the catch was searched with more detail, the net on the deck was inspected and cleaned, descriptions of each item were given and photos were taken.
    Discards monitoring in the Gillnet Sole Fishery
    Quirijns, F.J. - \ 2012
    [S.l.] : S.n. - 6
    tong (vis) - visserij - zeevisserij - vis vangen - netten - discards - bijvangst - monitoring - dover soles - fisheries - marine fisheries - fishing - nets - discards - bycatch - monitoring
    The Gillnet Sole Fishery Study Group monitored discards since 2011. This document describes results from the self-sampling. No observer trips in the Dutch Sole Gillnet Fishing have taken place under the EU data collection framework (DCF). Under the DCF The Netherlands are obliged to sample ten gill net fishing trips. However, it is not specified which type of gill net fishing trips should be sampled, i.e. no target species is specified. In 2011 observers only went on board gill net trips in which cod was targeted. In 2012, up to November 2012, no observer trips were carried out in these fisheries
    Options for delivering Ecoystem-based Marine Mangament. Identification and management of the main human activities that compromise the operational objectives
    Piet, G.J. ; Jongbloed, R.H. ; Paijmans, A.J. - \ 2012
    Brussel : European Commission (Report / European Commission )
    mariene ecologie - aquatische ecosystemen - strategisch management - beschermingsgebieden - menselijke activiteit - zeevisserij - databanken - regio's - noordoost atlantische oceaan - middellandse zee - zwarte zee - marine ecology - aquatic ecosystems - strategic management - conservation areas - human activity - marine fisheries - databases - regions - northeast atlantic - mediterranean sea - black sea
    Two aims of ODEMM WP4 , “Management Strategies” is to: - Develop a range of realistically feasible management strategies or options for these activities, using different types of measures and tools, to achieve regional Operational Objectives; - Apply a formal evaluation of these management strategies using a Management Strategy Evaluation (MSE) tool. The Marine Strategy Framework Directive (MSFD) identified the following marine regions: - the Baltic Sea; - North-east Atlantic Ocean; - Mediterranean Sea; - the Black Sea. This document combines Milestones 6, 7 and 8. Milestone 6 is a summary report showing the human activities revealed to be most likely to compromise the achievement of operational objectives in each region. Milestone 7 is a report detailing the indicators and management measures selected for each of the major issues highlighted in each regional sea. Milestone 8 comprises a list of possible management strategies for each of the selected operational objectives in each region. These milestones are reported together in this document because the work in these milestones is complementary and the combined reporting allows an overall synthesis of the work done so far.
    Haringbestand groter, visserijdruk lager : nieuw inzicht op omvang bestand noopt tot evaluatie beheerplan Noordzeeharing
    Hintzen, N.T. - \ 2012
    Visserijnieuws 32 (2012)25. - ISSN 1380-5061 - p. 4 - 4.
    haringen - visbestand - visstand - zeevisserij - visserijbeheer - wiskundige modellen - noordzee - europese unie - herrings - fishery resources - fish stocks - marine fisheries - fishery management - mathematical models - north sea - european union
    Het bestand Noordzeeharing blijkt substantieel groter dan gedacht, en de visserijdruk lager. Gezien de veranderingen in de perceptie van het Noordzeeharingbestand hebben onderzoekers van de ICES Haringwerkgroep geadviseerd om het Noordzeeharing-beheerplan te evalueren. Dit beheerplan wordt door de EU en Noorwegen gebruikt voor het beheer van de haringvisserij op de Noordzee. Niels Hintzen van Wageningen UR IMARES legt uit.
    GHG Emissions in aquatic production systems and marine fisheries
    Rasenberg, M.M.M. ; Poelman, M. ; Smith, S.R. ; Hoof, L.J.W. van - \ 2012
    IJmuiden : IMARES (Report / IMARES 13/IMA0525) - 12
    aquacultuur - zeevisserij - aquacultuursystemen - broeikasgassen - emissie - aquaculture - marine fisheries - aquaculture systems - greenhouse gases - emission
    In 2012, a total of 148 million tonnes of fish was supplied to the world by aquaculture and capture fisheries, of which 128 million tonnes of fish was used as food for people (FAO, 2012). Fish and fish products are an important source of protein and micronutrients in nutrition. These products accounted in 2009 for 16,6% of the world’s population intake of animal protein and 6,5% of all protein consumed (FAO, 2012a). Therefore, it is an important global food source for many people. Available knowledge on the emissions of greenhouse gases (GHG) released from aquaculture systems and capture fisheries is rather limited. In 2012, FAO organized an expert workshop on greenhouse gas emissions strategies and methods in seafood (FAO, 2012b). The conclusion of this workshop is that no sound estimation of global GHG emissions can be made as only few data and assessments are available for mainly large scale fish production (gadoids and salmonids) at company level in developed countries. Higher level assessments at industry group, national and global level requires generic approaches and filling of the data gap concerning GHG emissions related to fish production in Asia and Africa.
    Maatregelen voor de aanlandplicht. 4B: Incentives en disincentives
    Buisman, F.C. - \ 2012
    Den Haag : LEI, onderdeel van Wageningen UR - 10
    visserijbeleid - zeevisserij - bijvangst - discards - europese unie - scenario-analyse - fishery policy - marine fisheries - bycatch - discards - european union - scenario analysis
    In de Visserraad van juni 2012 door de EU ministers een principe akkoord bereikt over een “algemene benadering” (‘general approach’) ten aanzien van de herziening van het Gemeenschappelijk Visserijbeleid. Een van de onderdelen van de general approach is een aanlandplicht die geleidelijk ingevoerd zou moeten worden. Naar verwachting zal in het eerste semester van 2013 een akkoord worden gezocht over de aanlandplicht. In het Beleidsondersteunend Onderzoek voor het Ministerie van Economische Zaken, brengen IMARES en LEI in kaart wat de mogelijk impact zal zijn, zowel ecologisch als sociaal-economisch, van een aanlandplicht voor de verschillend Nederlandse visserij sectoren. Daarbij wordt gekeken naar drie verschillende scenario's: de general approach, het voorstel van de Nederlandse overheid en het voorstel van de Europese visserijsector.
    Gerichte visserij op Noordzeekrab
    Steenbergen, J. ; Rasenberg, M.M.M. ; Hammen, T. van der; Bierman, S.M. - \ 2012
    IJmuiden : IMARES (Rapport / IMARES Wageningen UR C153/12) - 27
    zeevisserij - krabben (schaaldieren) - schaal- en schelpdierenvisserij - visbestand - noordzee - marine fisheries - crabs - shellfish fisheries - fishery resources - north sea
    Gerichte visserij op Noordzeekrabben (Cancer pagarus) wordt hoofdzakelijk uitgevoerd in Engeland, Ierland en Frankrijk. Momenteel is de status van het bestand in de centrale Noordzee laag en rond het minimum. Dit blijkt uit Engelse bestandsschattingen. In Nederland zijn recentelijk twee vissers gericht gaan vissen op Noordzeekrab. Er is vrijwel geen beheer van visserij op Noordzeekrab in Nederland. Wanneer de visserij intensiteit toeneemt zonder beheer, bestaat het gevaar van overbevissing. Het is dan ook de vraag hoe het gesteld is met de Noordzeekrab voor en rondom de Nederlandse kust. Bestaande informatie over het Noordzeekrabbenbestand is in dit rapport toegankelijk gemaakt. Het gaat hierbij om gegevens die worden verzameld tijdens surveys en aanlandingsgegevens van alle vormen van visserij. Uit de surveys en de aanlandingsgegevens blijkt dat de meeste Noordzeekrabben voorkomen in de Duitse bocht. In dit gebied lijken de aantallen Noordzeekrabben te zijn toegenomen. De gebruikte surveygegevens geven een trend weer, maar zeggen nog niets over de toestand van het bestand. De meeste Noordzeekrabben worden in de zomer en het najaar aangeland. Om meer inzicht te krijgen in het vangstsucces van de gerichte visserij op Noordzeekrab zijn gegevens van 1 seizoen vissen door dhr. Kramer bijgehouden. Door een logboek bij te houden komt gedetailleerde informatie beschikbaar dat in de toekomst in combinatie met de survey gegevens kan worden gebruikt voor het inschatten van de toestand van de Noordzeekrab. Deze informatie dient als basis voor verdere invulling van een duurzame visserij op Noordzeekrab
    State of the Art Marien onderzoek
    Jak, R.G. ; Jongbloed, R.H. ; Lindeboom, H.J. - \ 2012
    Den Helder : IMARES (Rapport / IMARES Wageningen UR C158/12) - 93
    onderzoeksprojecten - wetenschappelijk onderzoek - onderzoeksinstituten - onderzoeksbeleid - coördinatie van onderzoek - kennismanagement - kennisniveau - mariene biologie - mariene ecologie - zeevisserij - nederland - noordzee - research projects - scientific research - research institutes - research policy - research coordination - knowledge management - knowledge level - marine biology - marine ecology - marine fisheries - netherlands - north sea
    In het kader van het kennisbasisonderzoek heeft IMARES op verzoek van EL&I de huidige kennis en de kennisbehoefte betreffende belangrijke mariene kennisvelden in beeld gebracht. Op verschillende terreinen vindt marien onderzoek plaats op voor EL&I relevante terreinen voor de Noordzee en de Delta. Een deel van dit onderzoek wordt (mede) door EL&I gefinancierd. Binnen dat onderzoek speelt IMARES (al dan niet in samenwerking met andere onderdelen van de WUR) een centrale rol in de coordinatie en kennisleverantie aan EL&I. Voor een tiental in overleg met EL&I gedefinieerde kennisvelden is een overzicht gemaakt van de status van het kennisveld m.b.t. de beantwoorde en nog niet beantwoorde kennisvragen. Voor elk kennisveld is door een team van betrokken IMARES-experts een beschrijving gegeven van het kennisveld, van het lopend onderzoek en de daaruit opgedane kennis, en van de nog resterende kennisvragen. Van 63 resterende kennisvragen is in een workshop de prioriteit vastgesteld voor EL&I, IMARES, IenM en bedrijfsleven.
    Wettelijke Onderzoek Taken WOT-05 Visserijonderzoek: Werkafspraken en werkplan 2013
    Beek, F.A. van - \ 2012
    IJmuiden : Centrum voor Visserijonderzoek (CVO rapport / Centrum voor Visserijonderzoek (CVO) 12.009) - 90
    visserij - binnenvisserij - zeevisserij - aquacultuur - fisheries - freshwater fisheries - marine fisheries - aquaculture
    Dit rapport beschrijft het werkplan 2013 van cluster WOT-05 Visserijonderzoek van Wageningen UR. In dit programma worden Wettelijke Onderzoek Taken uitgevoerd die betrekking hebben op het beheer van de visserij op zee, in Nederlandse kust- en binnenwateren en de aquacultuur.
    Evaluation of Proposed Amendments to the North Sea Flatfish Multiannual Plan
    Coers, A. ; Miller, D.C.M. ; Poos, J.J. - \ 2012
    IJmuiden : IMARES (Report / IMARES Wageningen UR C130/12) - 79
    zeevisserij - visstand - visserijbeleid - noordzee - nederland - marine fisheries - fish stocks - fishery policy - north sea - netherlands
    The evaluation of the multiannual plan is carried out using a numerical simulation model to study the interplay between the biological dynamics of the stocks and the dynamics of the fleet. The biological operating model consists of age structured population models of the ‘true’ plaice and sole stocks in the North Sea, following current stock delineations
    Van Noordzeevisser naar multipurpose maritiem ondernemer
    Taal, C. ; Bogaardt, M.J. - \ 2012
    Utrecht : InnovatieNetwerk (Rapport / InnovatieNetwerk nr. 12.2.309) - 58
    visserij - zeevisserij - ondernemerschap - visserijbeleid - nevenactiviteiten - noordzee - fisheries - marine fisheries - entrepreneurship - fishery policy - ancillary enterprises - north sea
    Voor visserijondernemers die hun activiteiten op zee willen verbreden liggen er vooral mogelijkheden op het gebied van inzet van schepen voor (bio)marien en maritiem onderzoek (zee- en visserijonderzoek), voor 'zeeboerderijen' tussen windmolens (vis- en zeewierkwekerijen), en voor het verzamelen van afval uit zee ('schoonvissen'). In deze relatief nieuwe (potentiële) markten kan de kottervisserijsector met betrekkelijk lage investeringen taken op zee naar zich toe trekken waardoor ondernemers hun kotters multifunctioneel kunnen inzetten met betere economische perspectieven.
    Masterplan Duurzame Visserij; Haalbaarheidsonderzoek 2e fase
    Taal, C. ; Hoefnagel, A. - \ 2012
    Den Haag : LEI, onderdeel van Wageningen UR (Nota / LEI : Natuurlijke hulpbronnen ) - 67
    visserij - visserijbeheer - vissersschepen - innovaties - duurzaamheid (sustainability) - zeevisserij - noordzee - fisheries - fishery management - fishing vessels - innovations - sustainability - marine fisheries - north sea
    De Stuurgroep Masterplan duurzame Visserij heeft samen met vijf specifieke werkgroepen (Techniek, Financiën, Bestuur en politiek, Aanwending bestaande schepen en Duurzaamheid) onderzoek verricht naar vernieuwingskansen voor de platvisvloot. Er is vooral gekeken naar effecten op economische en duurzaamheidsindicatoren bij rigoureus innoveren in de scheepsbouw en in visserijmethoden.
    Seminar: Fish traps in the North Sea : a viable option?
    Vos, B.I. de - \ 2011
    Kenniskringen Visserij
    zeevisserij - visserij - vis vangen - vistuig - vallen - noordzee - marine fisheries - fisheries - fishing - fishing gear - traps - north sea
    In several countries fishers use fish traps. In the Netherlands not many fishers have experience in using this kind of gear. The seminar aimed to stimulate exchange of international experiences and to inform Dutch fishermen (small scale, set net and rod & line fishermen) about this kind of gear. It was supposed to give an answer to the question whether fishing with fish traps is a viable option for Dutch fishers fishing in the North Sea. Finally, ideas on how to move forward should be generated.
    Notes and comments on the ex-post evaluation of the fisheries agreement EU-Morocco
    Brunel, T.P.A. - \ 2011
    IJmuiden : IMARES (Report / IMARES Wageningen UR C160/11) - 8
    zeevisserij - visserijbeleid - visserijbeheer - internationale verdragen - evaluatie - europese unie - marokko - marine fisheries - fishery policy - fishery management - international agreements - evaluation - european union - morocco
    This report presents a summary of the content of the ex-post evaluation of the fishing agreement between the EU and Morocco.
    Notes and comments on the ex-post evaluation of the fisheries agreement EU Mauritania
    Brunel, T.P.A. - \ 2011
    IJmuiden : IMARES (Report / IMARES Wageningen UR C096/11) - 16
    zeevisserij - visserijbeheer - visserijbeleid - evaluatie - internationale verdragen - europese unie - mauritanië - marine fisheries - fishery management - fishery policy - evaluation - international agreements - european union - mauritania
    This report presents a summary of the content of the ex-post evaluation of the fishing agreement between the EU and Mauritania.
    Discards monitoring in the Gillnet Sole Fishery
    Quirijns, F.J. ; Couperus, A.S. ; Helmond, A.T.M. van - \ 2011
    [S.l.] : S.n. - 12
    tong (vis) - visserij - zeevisserij - vis vangen - netten - discards - bijvangst - monitoring - dover soles - fisheries - marine fisheries - fishing - nets - discards - bycatch - monitoring
    The Gillnet Sole Fishery Study Group started discards monitoring. Data were supposed to be collected in three different ways: Self-sampling, catch monitoring by means of onboard cameras (CCTV) and monitoring under the Data Collection Regulation.
    Afzetmarkt van tong en andere vissoorten van staandwantvissers : uitwerking van een kennisvraag voor de Kenniskring Staandwantvisserij op tong
    Vos, B.I. de - \ 2011
    Den Haag : LEI Wageningen UR - 11
    tong (vis) - kabeljauw - limanda limanda - tarbot - scophthalmus rhombus - zeevisserij - bijvangst - duurzaamheid (sustainability) - certificering - visbestand - marketing - dover soles - cod - limanda limanda - turbot - scophthalmus rhombus - marine fisheries - bycatch - sustainability - certification - fishery resources - marketing
    Tong van staandwantvissers is nu ruim 1,5 jaar gecertificeerd met het MSC-keurmerk. Naast tong wordt er ook kabeljauw, schar, tarbot en griet gevangen door deze vissers. Vissers willen bekijken of de bij-soorten ook onder een duurzaamheidslabel verkocht kunnen worden. De vraag is echter welk label hiervoor het meest geschikt zou zijn. Een kanttekening bij MSC is bijvoorbeeld dat voor elke vissoort apart een certificeringstraject doorlopen moet worden. Dit is erg kostbaar en tijdrovend. Bovendien komt kabeljauw niet in aanmerking vanwege de onder druk staande bestanden. Om klantgericht te werken is het belangrijk uit te zoeken wat de afzetmarkt is van genoemde vissoorten en welk label daar het beste past. Idealiter zou de gehele vangst onder een label verkocht moeten worden. Vissers hebben de voorkeur om de MSC-certificering voor tong te behouden, omdat zij op dit moment de enige in Nederland zijn die het certificaat voor tong hebben en hier ook investeringen voor zijn gemaakt.
    Vangstvergelijking tussen pulskorschepen en een conventioneel boomkor-vaartuig
    Marlen, B. van; Wiegerinck, J.A.M. ; Os-Koomen, E. van; Barneveld, E. van; Bol, R.A. ; Groeneveld, K. ; Nijman, R.R. ; Buyvoets, E. ; Vandenberghe, C. ; Vanhalst, K. - \ 2011
    IJmuiden : IMARES (Rapport / IMARES Wageningen UR C122a/11) - 65
    pulsvisserij - zeevisserij - boomkorvisserij - vismethoden - visvangsten - pulse trawling - marine fisheries - beam trawling - fishing methods - fish catches
    In mei 2011 (week 19) werd een vergelijkende visserij uitgevoerd aan boord van de kotters GO4 (wekkerboomkorren), TX36 (HFK pulswings), en de toenmalige versie van DELMECO pulskorren gebruikt op de TX68. De schepen visten zoveel mogelijk giek-aan-giek in hetzelfde gebied. Tevens werd aandacht besteed aan mogelijk ruggengraatletsel van kabeljauw en wijting. De pulskarakteristieken waren als volgt: TX36: voltage 45 V0 tot piek, pulsfrequentie: 45 Hz, pulsduur 380 µs; elektrisch vermogen op één tuig: 7.0 kW; TX68: voltage 50 V0 tot piek, pulsfrequentie: 50 Hz, pulsduur 220 µs; elektrisch vermogen op één tuig: 8.5 kW. Het brandstofverbruik over de gehele visweek was aanzienlijk minder voor de TX36 (40%) en de TX68 (54%), dan de GO4. Voor de netto besomming (= bruto besomming – gasoliekosten) vonden we zelfs bijna een verdubbeling in efficiëntie voor de TX36 (186%), en een ruime toename voor de TX68 (155%). De schepen met pulstuigen vingen minder (65-69%) van de belangrijkste doelsoorten dan het schip met wekkerkorren op dit bestek en in deze periode, maar ook minder (30-50%) ondermaatse en niet-vermarktbare soorten vis (EN: ‘discards’) en minder bodemdieren (48-73%). De pulstuigen bleken minder (19-42%) maatse kabeljauw in kg/u te vangen dan de wekkerkor, maar de vangsten van deze soort waren voor alle schepen gering. Voor schol en schar waren de verschillen statistisch aantoonbaar, voor griet, tarbot wijting en kabeljauw niet. De pulskorschepen onderling lieten geen duidelijke verschillen in totale aanlanding zien. De TX68 bleek minder maatse tong te vangen, maar niet duidelijk minder ondermaatse tong dan de GO4. Bij de TX36 was het andersom: hier werd minder ondermaatse tong gevangen, maar het verschil in maatse vis was niet duidelijk. De vangsten van griet en tarbot waren zo gering, dat doorgaans geen statistisch onderbouwde conclusie kon worden getrokken. Alleen van ondermaatse tarbot ving de TX36 significant minder. Voor wijting vonden we wel een aanwijsbare vermindering van zowel maatse als ondermaatse vis voor de pulskorschepen. In aantal/u bleek de TX36 ook minder te vangen. Er was een redelijke overeenkomst tussen het vangstsucces (vangst per eenheid van inspanning of CPUE) berekend uit de afslaggegevens en het vangstsucces berekend uit de bemonsterde trekken voor soorten die talrijk voorkomen, zoals schol en tong. Voor minder voorkomende soorten, was de correlatie minder sterk. Dit zou voorkomen kunnen worden door meer en grotere monsters te nemen in toekomstige vangstvergelijkingen. Kabeljauw (ondermaatse en maatse vis) ondervond in de pulstuigen in beperkte mate breuk van de ruggengraat. Er is een indicatie, dat dit voor de TX68 iets meer (11%) optrad dan voor de TX36 (7%). Wijting leek nauwelijks schade te ondervinden.
    International survey blauwe wijting. Elke seconde een sample
    Faessler, S.M.M. - \ 2011
    Visserijnieuws 31 (2011)21. - ISSN 1380-5061 - p. 24 - 27.
    wijting - visbestand - visserijbiologie - akoestisch sporen - zeevissen - zeevisserij - whiting - fishery resources - fishery biology - acoustic tracking - marine fishes - marine fisheries
    IJMuiden- in 2011 wordt voor het eerst de jaarlijkse blauwe wijting survey gecoördineerd door Schascha Fässler, geboren Zwitser en sinds 2009 als 'fisheries acoustics' scientist' werkzaam bij IMARES in IJmuiden. In onderstaand artikel gaat Fässler nader in op acoustics in het algemeen en de survey van 2011 door samenwerkende Europese visserijbiologen in het bijzonder. "Het gebruik van onderwater acoustics' in het algemeen en de survey van 2011 door samenwerkende Europese visserijbiologen in het bijzonder. "Het gebruik van onderwater acoustics zal steeds belangrijker worden in de toekomst."
    Data availibility for the fisheries impact assessment of the FIMPAS project
    Hal, R. van; Teal, L.R. ; Asjes, J. ; Jak, R.G. ; Scheidat, M. ; Craeymeersch, J.A.M. ; Bemmelen, R.S.A. van; Quirijns, F.J. ; Polanen-Petel, T. van; Deerenberg, C.M. - \ 2010
    IJmuiden : IMARES (Report / IMARES Wageningen UR C052/10) - 119
    visserij - zeevisserij - natura 2000 - natuurbescherming - noordzee - fisheries - marine fisheries - natura 2000 - nature conservation - north sea
    The project Fisheries Measures in Protected Areas (FIMPAS) aims to introduce fisheries measures in the marine Natura 2000 sites within the Exclusive Economic Zone of the Dutch part of the North Sea by the end of 2011. The FIMPAS project covers three such areas, the Dogger Bank and the Cleaver Bank (both to be designated for protection under the Habitats Directive) and the Frisian Front (to be designated for protection under the Birds Directive). These sites are beyond the Dutch 12 nm zone and several EU Member States fish within these areas. Therefore fisheries measures must be implemented through the Common Fisheries Policy. These marine protected areas, as well as the potential fisheries measures, are a consequence of the implementation of the European Birds and Habitats Directives and will be proposed to the European Commission by the Dutch government. The Dutch Ministry for Agriculture, Nature and Food Quality (LNV), together with Dutch environmental NGOs and the Dutch fishing industry, are cooperating within the FIMPAS project to develop the necessary fisheries measures to achieve the conservation objectives for the Dutch Natura 2000 sites of the North Sea. LNV has asked the International Council for the Exploration of the Sea (ICES) to organize the necessary scientific processes and give advice on the desired fisheries measures involving the relevant stakeholders in this process.
    FIMPAS project - Pre - assessment of the impact of fisheries on the conservation objectives of Dutch marine protected areas
    Deerenberg, C.M. ; Teal, L.R. ; Beare, D.J. ; Wal, J.T. van der - \ 2010
    IJmuiden : IMARES (Report / Wageningen IMARES UR C071/10) - 82
    visserij - eu regelingen - kustgebieden - visserij-ecologie - zeevisserij - natuurbeleid - habitatrichtlijn - fisheries - eu regulations - coastal areas - fisheries ecology - marine fisheries - nature conservation policy - habitats directive
    The project Fisheries Measures in Protected Areas (FIMPAS) aims to introduce by the end of 2011 fisheries measures in the marine Natura 2000 sites within the Exclusive Economic Zone of the Dutch part of the North Sea. The FIMPAS project will deal with three such areas, the Dogger Bank and the Cleaver Bank (both to be designated for protection under the Habitats Directive) and the Frisian Front (to be designated for protection under the Birds Directive). These sites are located within the Exclusive Economic Zone of the Netherlands beyond the Dutch 12 nm coastal zone. Several EU Member States fish within these areas. Therefore fisheries measures must be implemented through the Common Fisheries Policy. These marine protected areas, as well as the potential fisheries measures, are a consequence of the implementation of the European Birds and Habitats Directives and will be proposed to the European Commission by the Dutch government. The Dutch Ministry for Agriculture, Nature and Food Quality (LNV), together with Dutch environmental NGOs and the Dutch fishing industry, are cooperating within the FIMPAS project to develop the necessary fisheries measures to achieve the conservation objectives for the Dutch Natura 2000 sites of the North Sea.
    Management challenges from technological development in commercial fisheries
    Eigaard, O.R. - \ 2010
    Wageningen University. Promotor(en): Adriaan Rijnsdorp, co-promotor(en): J.R. Nielsen. - [S.l. : S.n. - ISBN 9789085856801 - 113
    visserij - visserijbeheer - visbestand - vistuig - vissersschepen - technologie - duurzaamheid (sustainability) - europa - zeevisserij - visstand - visvangsten - fisheries - fishery management - fishery resources - fishing gear - fishing vessels - technology - sustainability - europe - marine fisheries - fish stocks - fish catches
    The major objective of this synthesis has been to throw light on how technological development in fisheries can complicate efforts to balance harvesting capacity and fish resources. The basis of achieving this objective has been the compilation of technological data from a selection of European fisheries, which cover some main principles of how technological development influences catch rates and fishing mortality. This work has been based largely on sociological approaches in the form of interviews with fishermen, gear manufacturers, ship yards, suppliers of electronic equipment, etc., as well as exploration of historical and commercial data from the same type of sources. That is, retrieval of technological data in very incompatible formats from a broad and heterogeneous set of sources and structuring the data in an operational manner.
    Building on this empirical material a bottom-up analytical framework embracing technical, economical, sociological and biological aspects was established, in which to understand the technological development in fisheries and its effects on the marine resources. Using this framework the concept of technological development was related to the main components and mechanisms of the European fisheries system. It was established i) how new fishing technology is developed in a bifurcated process of either radical or gradual nature, ii) how the speed and extent of technology spread is very uneven among the different vessel groups of the commercial fleet, iii) how catch increase is the main driver of technology uptake on board the vessels, iv) how this objective can be achieved through technologically mediated improvements of gear catchability, fish finding and navigation and effort utilisation at sea, and v) how both input and output oriented fisheries management is challenged by these bearings of technological development in commercial fisheries.
    The main message from this bottom-up approach was that irrespective of the management system in force technological development in commercial fisheries will take place with catch efficiency increases as the main driver and the main effect.
    Even though radical and gradual development of technology in fisheries is inevitable, and almost indifferent to the regulations in force, the sensitivity of the main management principles to the effects of technological development are far from uniform. This became evident as analyses of five European case study fleets demonstrated i) how technological development can complicate output control by adding uncertainty to standard stock assessment procedures, ii) how short-term input control (in terms of effort quotas) can be undermined by technologically induced efficiency increases, which decouple nominal effort from effective effort, and iii) how long-term input control (in terms of buy back schemes and other capacity control measures) are also undermined by efficiency changes from both temporal and structural technological development.
    The main shortcomings of both output and input oriented management strategies were explored further in relation to the undesired effects from technological development, as well as a multitude of other factors, which have been shown to influence catchability and the reliability of official catch and effort data (e.g. targeting behaviour, discards, high-grading, and environmental conditions). Following this exploration of advantages and disadvantages of the main type of management strategies available, the possibilities of integrating technological development to improve biological sustainability and achieve better agreement with policy objectives were identified and summarized as follows:
    i) The undesired effects of technological development are limited in output controlled fisheries and almost solely restricted to complicating the setting of appropriate TACs, if time series of commercial effort data are part of the underlying stock assessments. When this is the case, assessment procedures should be scrutinized for bias from efficiency trends on a regular basis and time series should be corrected accordingly. However, although insensitive to technological development, the inability of output control to cope with discards and misreporting are serious shortcomings, which in many fisheries have resulted in failure to meet management objectives.
    ii) In contrary, the undesired effects of technological development are comprehensive and difficult to counter in short-term input control systems (effort management). The problem of mismatch between nominal and effective effort can only be solved partly with improved descriptors and the remaining task of predicting and mitigating catchability trends in a system as complex as the commercial fishery is not feasible on a broad basis. Other factors such as targeting behaviour and skipper skills can also contribute substantially to a decoupling of nominal effort from effective effort and with that a mismatch between intended and realized fishing mortality. A great advantage of direct effort control as sole regulation in force is that it gives very little incentive to discard or misreport.
    iii) Fishing power increases from technological development also substantially undermine long-term input control (capacity management), but counteracting these effects with improved capacity descriptors and long-term efficiency projections by major vessel groups is relatively straight forward. However, the long-term perspective of capacity management does not fit well with the changeable character of biological systems, for which reason supplementing short-term regulations (i.e. elements of (i) or (ii) above) are required.
    Consequently, integration of technological development in fisheries management - and of other factors undermining policy objectives - is not a question of either input or output control, but of understanding the complexity of the fisheries system and of tailor making solutions from the mixed input and output regulation toolbox on as fine a scale as possible.



    Kenniskring Puls- en SumWingvisserij op platvis
    Taal, C. - \ 2010
    visserij - vistuig - pleuronectiformes - vismethoden - pulsvisserij - zeevisserij - kennisoverdracht - fisheries - fishing gear - pleuronectiformes - fishing methods - pulse trawling - marine fisheries - knowledge transfer
    Kenniskringen zijn (studie-)groepen van vissers die zelf uitdagingen, vragen of problemen geformuleerd hebben. Samen met andere belanghebbenden en onderzoeksinstellingen zoeken zij naar oplossingen voor een duurzamere vangst en beter economisch perspectief. Dit document gaat over de kenniskring van de Puls- en SumWing-visserij op platvis. De Pulsvissers richten zich hoofdzakelijk op tong. Andere platvissoorten die op de zeebodem leven zoals schol, schar, tarbot en griet completerenvangst.
    IRMM HCB and HCBD in Blankvoorn (testmaterial for reference material)
    Hoek-van Nieuwenhuizen, M. van - \ 2010
    IJmuiden : IMARES (Report / IMARES Wageningen UR no. C113/10) - 7
    waterkwaliteit - rutilus rutilus - monitoring - toxische stoffen - referentienormen - biologische monitoring - ecotoxicologie - visserij-ecologie - zeevisserij - kaderrichtlijn water - water quality - rutilus rutilus - monitoring - toxic substances - reference standards - biomonitoring - ecotoxicology - fisheries ecology - marine fisheries - water framework directive
    Blankvoorn Nieuwe Merwede (Roach, Rutilus rultilus) has been tested as a reference material for the components HCBD and HCB for biota monitoring according to the Water Framework Directive. Both components in the blankvoorn are present at moderate levels (overall average levels of respectively HCBD 1.6 μg/kg and HCB 6.2 μg/kg). These concentrations are far above reporting limits (respectively 0.1 μg/kg for HCBD and 0.2 μg/kg for HCB) and should therefore be suitable for use in a reference material.
    Evolutionary effects of fishing and implications for sustainable management: a case study of North Seas plaice and sole
    Mollet, F.M. - \ 2010
    Wageningen University. Promotor(en): Adriaan Rijnsdorp. - [S.l. : S.n. - ISBN 9789085856139 - 202
    schol - tong (vis) - visserij - vis vangen - evolutie - rijpen - groei - voortplanting - levensgeschiedenis - kenmerken - adaptatie - visserijbeheer - duurzaamheid (sustainability) - zeevisserij - experimentele evolutie - plaice - dover soles - fisheries - fishing - evolution - maturation - growth - reproduction - life history - traits - adaptation - fishery management - sustainability - marine fisheries - experimental evolution
    Exploited resources might genetically evolve as a consequence of ex¬ploitation by adapting their life history to the imposed mortality re¬gime. Although evolution favors traits for survival and reproduction of the fittest, human-induced evolution might have negative consequences for the exploiter. In general, a shift towards lower growth rate, earlier maturation and increased reproductive investment might be expected from increased (unselective) mortality and these changes might lead to generally smaller exploited individuals. Hence, the evolution might ne¬gatively affect the productivity of the resource and thus the sustainable exploitation and furthermore, genetic changes might be slow to reverse. If selection forces are high, evolution might occur fast and be observa¬ble within a few decades. Fisheries provide a large scale experiment for fisheries-induced evolution (FIE) since fishing mortality rates, typically being size-selective, exceed natural mortality rates by a multiple and data samples are available for decadal time scales. This thesis aims to assess the potential importance of FIE for sustainable exploitation by empirical evidence as well as evolutionary modeling, illustrated for the North Sea flatfish plaice and sole.
    In empirical studies the problem of inferring on genetic changes from phenotypic observations lies in the disentangling of the phenotypic plasticity caused by environmental variations from the potential gene¬tic change. This is at least partly achieved by constructing norms of reaction that account for this environmental variation. The probabi¬listic maturation reaction norm for instance disentangles phenotypic plasticity in maturation caused by variation in growth. Because growth, maturation and reproductive investment are correlated due to tradeoffs on the individual level, a method was developed that fits an energy al¬location model to individual growth trajectories, obtained by the back-calculation of otoliths. This method provides size-specific estimates of the mechanistic individual life history tradeoffs and of the selection differentials imposed by the fishery. Because the correlation of esti¬mated life-history traits is captured, temporal changes could (for the first time) be analyzed conditionally on the correlation and on potenti¬al environmental effectors, thus disentangling not only environmental variability but also effects from changes in another trait. The results suggest that maturation shifted to occur earlier, surplus energy and reproductive investment increased partly due to environmental factors, but that all changes also bear a genetic component, indicative for FIE.
    Species-specific individual-based eco-genetic models were developed to explore the evolutionary causes of reverse sexual size dimorphism in the case of flatfish. The hypothesis that males are smaller than fe¬males because of an energy loss through behavioural reproductive in¬vestments has to be rejected in this evolutionary perspective, since a higher demand on reproductive investment is compensated by increased energy acquisition. In contrast, the results show that males are smaller because increasing reproductive investment pays off less in males than in females. The finding can likely be generalized to many cases where mating opportunities are limited in space and time. Since eco-genetic models include the inheritance of traits with frequency-dependent se¬lection, they are therefore a powerful tool to study FIE and the model is therefore fitted to the estimated evolution of plaice and the evolu¬tionary impact of different management scenarios is assessed. The so called maximum sustainable yield MSY and the corresponding maximal fishing mortality FMSY evolve along with the population life history and occur both at lower levels after a while. The currently estimated refe¬rence points are thus not sustainable but slipping targets. By a dome-shaped exploitation pattern being protective for larger fish the evolu¬tionary trends could be reversed and with it the negative evolutionary impact. However, the evolutionary impact trades off against the short term loss in yield: by protecting the large fish the evolutionary impact is minimized but the instantaneous yield is decreased too – the optimal strategy for a given time horizon is somewhere in between. In summary, the thesis provides evidence that FIE should be taken into account for sustainable management.
    Norwegian Sea Herring Stock Discrimination phase I (NORDISI)
    Overzee, H.M.J. van; Dickey-Collas, M. ; Pennock, I. ; Tribuhl, S.V. ; Bierman, S.M. ; Damme, C.J.G. van; Warmerdam, M.J.M. - \ 2009
    IJmuiden : IMARES (Report / MARES Wageningen UR no. C142/09) - 28
    visserij - haringen - morfometrie - soortverschillen - monitoring - zeevisserij - biologische monitoring - fisheries - herrings - morphometrics - species differences - monitoring - marine fisheries - biomonitoring
    There is growing concern among fishermen about the migration of North Sea herring into the Norwegian Sea. The Pelagic Freezer-trawler Association therefore commissioned IMARES to develop a technique to monitor possible catches of North Sea herring in the Norwegian Sea. This technique will use morphometric (shape) differences in herring to distinguish between Norwegian Sea spawning herring and North Sea herring. The results show that the model is able to distinguish Norwegian spring spawning herring from North Sea autumn or winter spawning herring. Overall we can conclude that even though we still have to overcome some methodological problems we are confident that this research constitutes a first step towards developing a technique to monitor catches of herring from the Norwegian Sea for Norwegian Spring spawning or other herring.
    Discard sampling of Plaice (Pleuronectes platessa) and Cod (Gadus morhua) in the North Sea by the Dutch demersal fleet from 2004 tot 2008
    Aarts, G.M. ; Helmond, A.T.M. van - \ 2009
    Texel : IMARES (Report / Wageningen IMARES C094/09) - 35
    visserij - pleuronectiformes - beoordeling - bemonsteren - monitoring - nederland - zeevisserij - discards - visstand - fisheries - pleuronectiformes - assessment - sampling - monitoring - netherlands - marine fisheries - discards - fish stocks
    The PVis discard data used in the analysis presented in this report clearly shows where and when most discarding takes place. Although previous analysis (Aarts & van Helmond 2007) and the latest Flatfish Benchmark Assessment (2009), indicate that the data cannot be incorporated into the ICES stock assessment, it still provides an important reference points that can be used to evaluate the current DCR discard estimates and methods used. In 2009 Wageningen IMARES started a new DCR sampling program. The most remarkable difference with the previous program is the integration of self-sampling next to a less intensive observer program. We encourage this initiative, since the increase of discard data available over space and time will be of great value, but strongly recommend clarity of sampling procedures, thorough training and intensive communication with fishermen. Hence, inaccurate data on discards will have a significant impact on future management strategies.
    Implications of fisheries during the spawning season for the sustainable management and recovery of depleted fish stocks: life history characteristics of several North Sea species
    Overzee, H.M.J. van; Rijnsdorp, A.D. - \ 2009
    IJmuiden : IMARES (Report / IMARES Wageningen UR no. C095/09) - 17
    visserij - haringen - kabeljauw - makrelen - schol - zeekreeften - zolen - limanda limanda - tarbot - visserij-ecologie - zeevisserij - fisheries - herrings - cod - mackerels - plaice - lobsters - soles - limanda limanda - turbot - fisheries ecology - marine fisheries
    Fish traders and NGOs have put the idea forward that in order to not disturb the spawning process and hence improve the reproductive success of a fish population one should stop fishing during the spawning period. This idea has resulted in the project “Vis & Seizoen”. Within this project a theoretical framework is being developed to examine the possible effect of fishing during the spawning season. This is the first report within the project. It presents a summary of the life history characteristics that are related to the reproduction of nine important commercial fish species.
    Boomkorvisserij in de Voordelta: Omvang en mogelijkheden tot verduurzaming
    Deerenberg, C.M. ; Mesel, I.G. de; Jak, R.G. ; Quirijns, F.J. - \ 2009
    IJmuiden : IMARES (Rapport / Wageningen IMARES C059/09) - 18
    zeevisserij - boomkorvisserij - vis vangen - natura 2000 - voordelta - duurzaamheid (sustainability) - nadelige gevolgen - aquatische ecosystemen - marine fisheries - beam trawling - fishing - natura 2000 - voordelta - sustainability - adverse effects - aquatic ecosystems
    In de Voordelta is alleen boomkorvisserij met zgn. Eurokotters, met een nominaal motorvermogen tot 300pk (221kW) toegestaan. Deze schepen vissen vooral op platvissoorten. De intensiteit van deze visserij is sinds 2001 met ongeveer een derde afgenomen en de omvang met ongeveer de helft. Binnen de Voordelta werd vooral buiten het bodembeschermingsgebied gevist. Mogelijke knelpunten tussen de boomkorvisserij en de natuurdoelen van de Voordelta komen voort uit de effecten van de visserij op de structuur van de bodem en de aanwezige ecosystemen, op de hoeveelheid en samenstelling van de bodemsoorten (inclusief vissen) door verwijdering van individuen (vangst), en door verstoring (vluchten van individuen uit de nabijheid van het schip). Deze effecten, met uitzondering van verwijdering van de (aangelande) vangst, zijn alleen in algemene zin bekend, namelijk afgeleid van studies met grote boomkorschepen (>300 pk, 221kW). Ook de mogelijke maatregelen om effecten te minimaliseren zijn van meer algemene aard: aanpassing van tuig en/of maaswijdte, mijden van gebieden in ruimte en tijd.
    The effect of pulse stimulation on biota - Research in relation to ICES advice - Progress report on the effect to cod
    Haan, D. de; Marlen, B. van; Kristiansen, T.S. ; Fosseidengen, J.E. - \ 2009
    IJmuiden : IMARES (Report / IMARES Wageningen UR C098/08) - 22
    pulsvisserij - boomkorvisserij - kabeljauw - mariene ecologie - zeevisserij - pulse trawling - beam trawling - cod - marine ecology - marine fisheries
    In response to questions asked by ICES on the effects of pulse stimulation in commercial beam trawling on components of the marine ecosystem a number of preliminary studies were undertaken in the period between 1 September 2008 and 1 March 2009. These activities involved the exposure of cod to a simulated electric pulse under laboratory conditions and observation of behaviour, including the foraging response, and monitoring mortality and possible internal injuries such as vertebral damage by X-ray photography.
    Overview of the Dutch recreational fisheries for ICES WGSMRF 2009
    Keeken, O.A. van - \ 2009
    IJmuiden : IMARES (Internal report / Wageningen IMARES 09.010) - 14
    visserij - hengelsport - vis vangen - waterrecreatie - monitoring - gegevens verzamelen - zeevisserij - vismethoden - fisheries - angling - fishing - water recreation - monitoring - data collection - marine fisheries - fishing methods
    The new European Union commission decision of 6 November 2008 adopts a multiannual Community programme pursuant to Council Regulation (EC) No 199/2008 establishing a Community framework for the collection, management and use of data in the fisheries sector and support for scientific advice regarding the common fisheries policy (2008/949/EC). This programme includes the collection of data for recreational fisheries.
    Duurzaamheid van de mechanische wadpierenvisserij in de Waddenzee
    Leopold, M.F. ; Bos, O.G. - \ 2009
    Texel : IMARES (Rapport / Wageningen IMARES nr. C013/09) - 42
    zeevisserij - aquatische wormen - zeeproducten - duurzaamheid (sustainability) - waddenzee - visbestand - visserijbeheer - marine fisheries - aquatic worms - marine products - sustainability - wadden sea - fishery resources - fishery management
    In de Waddenzee beoefenen vier bedrijven de mechanische wadpierenvisserij: drie bedrijven op het oostelijke Balgzand en één bedrijf bij Texel. Samen vissen zij momenteel jaarlijks rond de 11,5 miljoen wadpieren (Arenicola marina) op. De pieren dienen als aas in de sportvisserij. Het bedrijf bij Texel slaagt erin al jarenlang met eenzelfde visserijinspanning min of meer dezelfde vangsten te halen. Op het Balgzand is de pierenstand sterk teruggelopen, mogelijk door overbevissing, en zijn de vangsten ongeveer gehalveerd terwijl het brandstofgebruik min of meer hetzelfde is gebleven. Om tot uitspraken te komen over de mate van duurzaamheid van deze vorm van visserij zijn de bedrijfsgegevens geanalyseerd van de pierenwinbedrijven, uitgaande van de stelling: Een visserij is duurzaam, als over een lange reeks van jaren de opbrengst niet daalt, en de zogenaamde catch per unit effort (CPU) (pieren per liter brandstof) niet verandert. De ontwikkeling van het wadpierenbestand op het Balgzand is geanalyseerd aan de hand van NIOZ data (beviste/onbeviste delen). Tevens is in dit rapport literatuuronderzoek verricht naar de ecologie van de wadpier, de effecten van pierenvisserij op het bodemleven en naar beheer bij andere kleinschalige vormen van bodemvisserij. De resultaten van deze studie zijn van belang in het kader van de vergunningverlening en voor het (verder) verduurzamen van deze vorm van visserij.
    De lege zee: feit of fictie? Bespiegelingen over duurzaam visserijbeheer
    Rijnsdorp, A.D. - \ 2008
    Wageningen : Wageningen Universiteit - ISBN 9789085852650 - 32
    visserij - visbestand - visserijbeheer - ecosystemen - duurzaamheid (sustainability) - zeevisserij - visserijbiologie - visstand - overexploitatie - openbare redes - fisheries - fishery resources - fishery management - ecosystems - sustainability - marine fisheries - fishery biology - fish stocks - overexploitation - public speeches
    De centrale vragen bij deze rede zijn: Hoeveel vis kan de zee produceren en hoe kan deze vis op een duurzame manier worden geoogst. Een beschouwing over visserijdruk, ontwikkeling van de biomassa, ecosysteemeffecten van de visserij, visserijbeheer, uitmondend in de vraag: lege zee, feit of fictie en de betekenis voor onderwijs en onderzoek
    Achtergronddocument over de Nederlandse zeevisserij voor het Consumentenplatform Visserij
    Hoefnagel, E. ; Oostenbrugge, J.A.E. van; Smit, J.G.P. ; Schelvis-Smit, A.A.M. ; Bult, T.P. ; Overzee, H.M.J. van; Quirijns, F.J. - \ 2008
    Den Haag : LEI (LEI VR2008-009) - 32
    zeevisserij - marine fisheries
    PRODUS dp 3: Effecten van sublitorale mosselzaadvisserij in de westelijke Waddenzee: situatie in eerste jaar van sluiting onderzoekvakken (najaar 2006)
    Fey-Hofstede, F.E. ; Brinkman, A.G. ; Craeymeersch, J.A.M. ; Heessen, H.J.L. ; Stralen, M. van; Dekker, R. - \ 2007
    Texel-IJmuiden : IMARES (Rapport / Wageningen Imares 07.017) - 72
    mossels - mytilidae - visserij - biomassa - biodiversiteit - nederland - milieueffect - milieueffectrapportage - zeevisserij - waddenzee - mussels - mytilidae - fisheries - biomass - biodiversity - netherlands - environmental impact - environmental impact reporting - marine fisheries - wadden sea
    Wettelijke Onderzoek Taken Visserijonderzoek WOT-05 Visserijonderzoek : werkafspraken en werkplan 2008
    Beek, F.A. van - \ 2007
    IJmuiden : CVO (CVO rapport 07.008) - 94
    visserij - aquacultuur - schaal- en schelpdierenvisserij - visserijbeheer - visserijbeleid - visbestand - statistiek - monitoring - onderzoek - nederland - zeevisserij - fisheries - aquaculture - shellfish fisheries - fishery management - fishery policy - fishery resources - statistics - monitoring - research - netherlands - marine fisheries
    Dit rapport bevat het werkplan voor 2008 van cluster WOT-05-406 Visserijonderzoek van DLO. In dit programma worden Wettelijke Onderzoek Taken uitgevoerd die betrekking hebben op het beheer van de visserij op zee en Nederlandse kust- en binnenwateren en de aquacultuur. Het onderzoek omvat een aantal uiteenlopende onderwerpen; Toestandsbeoordeling en beleidsadviezen visserij, Marktbemonstering zeevisserij, Bestandsopnamen op zee, Monitoring bijvangsten, Vis- en visserijonderzoek Binnenwateren, Visserijstatistiek, Monitoring schelpdierbestanden en Vrije ruimte. Het huidige programma is begonnen in 2002 en bestrijkt de periode t/m 2009. De inhoud van het programma betreft de advisering van het visserijbeleid in bovengenoemde gebieden en het verzamelen van gegevens die daarvoor nodig zijn
    Designing a decision support system for marine reserves management: an economic analysis for the Dutch North Sea
    Ding, Hongyu ; Ruijs, A.J.W. ; Ierland, E.C. van - \ 2007
    Milano : Fondazione Eni Enrico Mattei (Working Papers / Fondazione Eni Enrico Mattei paper 47) - 27
    marien milieu - visserij - biodiversiteit - zeevissen - soortendiversiteit - milieubescherming - noordzee - nederland - milieueconomie - zeevisserij - beslissingsondersteunende systemen - marine environment - fisheries - biodiversity - marine fishes - species diversity - environmental protection - north sea - netherlands - environmental economics - marine fisheries - decision support systems
    The authors explore how a Decision Support System (DSS) for managing the marine environment can be set up. They use the Driving force-Pressure-State- Impact-Respond (DPSIR) framework to analyze which are the major driving forces impacting upon the marine environment in the North Sea. Moreover, a number of potential responses are identified. Furthermore, a preliminary and simplified optimization model has been set up and can be used in a DSS to decide on the best location of marine reserves for the protection of species. The model is based on a bio-economic metapopulation model that can be used to decide which parts of the sea should be opened for fisheries and which should be protected as marine reserve. It accounts for the dispersal of fish and considers both the economic returns from fisheries and the ecological value of marine biodiversity. A number of suggestions are given on how to extend and improve the DSS.
    Indicators for the 'Convention on biodiversity 2010'. Exploration of the usefulness of the Marine Trophic Index (MTI) as an indicator for sustainability of marine fisheries in the Dutch part of the North Sea
    Fey-Hofstede, F.E. ; Meesters, H.W.G. - \ 2007
    Wageningen : Wettelijke Onderzoekstaken Natuur & Milieu (WOt-werkdocument 53.8) - 42
    biodiversiteit - duurzaamheid (sustainability) - visserij - noordzee - trofische graden - biologische productie - biologische indicatoren - indicatoren - nederland - zeevisserij - duurzaamheidsindicatoren - biodiversity - sustainability - fisheries - north sea - trophic levels - biological production - biological indicators - indicators - netherlands - marine fisheries - sustainability indicators
    The Marine Trophic Index (MTI) is proposed by the CBD as an indicator for sustainable fisheries and ecosystem integrity. This report explores the usefulness of the Marine Trophic Index (MTI) as an indicator for sustainable fisheries and ecosystem integrity for the Dutch situation
    Reisverslag Atlanto-Skandische haring survey, FRV Dana 2 - 31 mei 2007
    Couperus, A.S. ; Beek, F.A. van - \ 2007
    IJmuiden : IMARES (Rapport / Wageningen IMARES nr. 07.014) - 8
    visserij - haringen - vangstsamenstelling - opbrengsten - vistuig - akoestisch sporen - populatiedynamica - bevolkingsspreiding - migratie - inventarisaties - zeevisserij - visvangsten - onderwaterakoestiek - noordelijke atlantische oceaan - fisheries - herrings - catch composition - yields - fishing gear - acoustic tracking - population dynamics - population distribution - migration - inventories - marine fisheries - fish catches - underwater acoustics - north atlantic
    Management recommendations for the sustainable exploitation of mussel seed in the Irish Sea
    Maguire, J.A. ; Knights, T. ; Burnell, G. ; Smaal, A.C. - \ 2007
    Galway : Marine Institute (Marine environment and health series no. 31) - 83
    mossels - zaden - vis vangen - schaal- en schelpdierenvisserij - visserijbeheer - hulpbronnengebruik - duurzaamheid (sustainability) - ierse zee - zeevisserij - mussels - seeds - fishing - shellfish fisheries - fishery management - resource utilization - sustainability - irish sea - marine fisheries
    Resultaten van het RWS-RIKZ JAMP 2007 monitoringprogramma van schar (Limanda limanda L.): Biologische gegevens van schar en milieukritische stoffen in schar
    Velzeboer, I. ; Kotterman, M.J.J. - \ 2007
    IJmuiden : IMARES (Rapport / Wageningen IMARES nr. C100/07) - 15
    vissen - limanda limanda - monitoring - toxische stoffen - nederland - biologische monitoring - ecotoxicologie - visserij-ecologie - zeevisserij - fishes - limanda limanda - monitoring - toxic substances - netherlands - biomonitoring - ecotoxicology - fisheries ecology - marine fisheries
    Resultaten van bemonstering van vissen voor: PAK, DNA, PCB en HCB en zware metalen
    Het verband tussen visserij-inspanning en visserijsterfte
    Kraak, S.B.M. - \ 2007
    IJmuiden : IMARES (Rapport / Wageningen IMARES nr. C083/07) - 18
    visserij - vis vangen - vissersschepen - motoren - mortaliteit - arbeid (werk) - nederland - zeevisserij - visserij-ecologie - visvangsten - fisheries - fishing - fishing vessels - engines - mortality - labour - netherlands - marine fisheries - fisheries ecology - fish catches
    Effort management in a mixed North Sea flatfish fishery
    Machiels, M.A.M. ; Kraak, S.B.M. ; Oostenbrugge, H. van; Rijnsdorp, A.D. - \ 2007
    IJmuiden : IMARES (Rapport / Wageningen IMARES nr. C072/07) - 27
    visserij - vangstsamenstelling - visserijbeheer - visserijbeleid - pleuronectiformes - noordzee - visserij-ecologie - zeevisserij - visvangsten - fisheries - catch composition - fishery management - fishery policy - pleuronectiformes - north sea - fisheries ecology - marine fisheries - fish catches
    Brandstofbesparing bij boomkorren: een verkenning van technische aanpassingen, uitgevoerd door vissers in het kader van het Advies van de "Task Force Duurzame Noordzeevisserij"
    Bult, T.P. - \ 2007
    IJmuiden : IMARES (Rapport / Wageningen IMARES nr. C060/07) - 29
    visserij - visserijbeheer - vistuig - netten - brandstofverbruik - reductie - noordzee - vismethoden - zeevisserij - boomkorvisserij - fisheries - fishery management - fishing gear - nets - fuel consumption - reduction - north sea - fishing methods - marine fisheries - beam trawling
    In het kader van het Task Force Advies Duurzame Noordzee Kottervisserij (Anonymous 2006) zijn een aantal schippers en ondernemers een traject gestart waarbij aanpassingen werden gedaan aan de boomkor met als doel een substantiële vermindering het brandstofverbruik. Wageningen IMARES is gevraagd om de opgedane ervaringen te rapporteren aan LNV, met dit rapport als resultaat. Deze rapportage beschrijft de ontwikkelingen tot april 2007. De aanpassingen betroffen de volgende vier varianten: 1 Cirkelslof – Vervanging van de sloffen door een cirkel/wielconstructie 2 Spoiler – Aanpassing van de boom door gebruik van (flexibele) spoilerconstructies 3 Fly-Beam – Vervanging van de boom door een vaste vleugelconstructie 4 Zweefkor - Vervanging van de boom door een flexibele vleugel waarmee, afhankelijk van het bodemcontact en instellingen, ook zwevend gevist kan worden De verwachting was dat de aanpassingen leiden tot een brandstofbesparing van 10-25%. De verschillende tuigaanpassingen zijn in eigen beheer ontwikkeld.
    Waar zit de mul tegenwoordig? : interactieve atlas voor de vissoorten op de Noordzee
    Heessen, H.J.L. - \ 2006
    Visserijnieuws 26 (2006)14. - ISSN 1380-5061 - p. 4 - 4.
    zeevissen - noordzee - databanken - zeevisserij - marine fishes - north sea - databases - marine fisheries
    ICES heeft een nieuwe Atlas of North Sea Fishes gemaakt als een nieuwe database op internet. Vanuit deze visatlas kunnen kaartjes gepresenteerd worden van het voorkomen in de Noordzee van 15 commercieel belangrijke vissoorten. Grote trekkers van dit project zijn medewerkers van IMARES. Zij willen ook de andere 150 vissoorten in de database gaan opnemen
    Internationale bestandsopname IBTS: uitstekende jaarklas schelvis en kever: Opnieuw weinig jonge haring
    Hofstede, R. ter - \ 2006
    Visserijnieuws 26 (2006)13. - ISSN 1380-5061 - p. 4 - 4.
    visbestand - zeevissen - onderzoek - noordzee - zeevisserij - fishery resources - marine fishes - research - north sea - marine fisheries
    Verslag van de jaarlijkse International Bottom Trawl Survey (IBTS) uitgevoerd eind januari- begin maart in de Noordzee, het Skagerrak en het Kattegat
    Aquacultuurproductie: trends en uitdagingen
    Verdegem, M.C.J. - \ 2005
    Aquacultuur 6 (2005). - ISSN 1382-2764 - p. 48 - 54.
    aquacultuur - visproductie - visteelt - sectorale analyse - zeevisserij - aquaculture - fish production - fish culture - sectoral analysis - marine fisheries
    Er worden enkele mondiale trends geschetst op het gebied van de productie van vis, schelp- en schaaldieren. Er is een groeiende vraag naar vis, schaal- en schelpdieren. De groei zit vooral in ontwikkelingslanden, waardoor het aandeel van de aquacultuurproductie in de ontwikkelde landen verder af zal nemen
    Discards sampling of the Dutch beam trawl fleet in 2004
    Keeken, O.A. van; Pastoors, M.A. - \ 2005
    IJmuiden : CVO (CVO report 05.006) - 56
    schol - solea - bemonsteren - visbestand - noordzee - boomkorvisserij - zeevisserij - visstand - bijvangst - discards - plaice - solea - sampling - fishery resources - north sea - beam trawling - marine fisheries - fish stocks - bycatch - discards
    Scepsis sector jegens innovatie onnodig: mosselkwekers als duurzame natuurbeheerders
    Smaal, A.C. - \ 2005
    Visserijnieuws 25 (2005)39. - ISSN 1380-5061 - p. 8 - 11.
    visserij - explosieven - detectie - vis vangen - netten - beroepsgevaren - vissers - zeevisserij - fisheries - explosives - detection - fishing - nets - occupational hazards - fishermen - marine fisheries
    Ervaringen van de bemanning van mijnenjagers bij het opsporen, verslepen, en vernietigen van de door vissersvaartuigen gemelde explosieven. Eerder dit jaar was er een dodelijk ongeluk met een opgeviste bom op een kotter
    Weinig aanwas rondvis: internationale bestandsopnames IBTS
    Hofstede, R. ter - \ 2005
    Visserijnieuws 25 (2005)13. - ISSN 1380-5061 - p. 6 - 6.
    visbestand - zeevissen - onderzoek - noordzee - zeevisserij - fishery resources - marine fishes - research - north sea - marine fisheries
    Resultaten van de International Bottom Trawl Survey in de Noordzee. Het onderzoeksvaartuig Tridens heeft hier voor Nederland aan deelgenomen. Een belangrijk doel is inzicht te verkrijgen in de toestand van éénjarige haring, sprot en rondvis. Een vergelijking van de gemiddelde vangst van haring, kabeljauw en wijting in 2004 in vergelijking tot 1980-2003
    Voortgangsrapportage van het WOT programma 406: Wettelijke Onderzoek Taken Visserijonderzoek voor LNV in 2003
    Beek, F.A. van - \ 2004
    IJmuiden : RIVO (CVO rapport / Stichting DLO, Centrum voor Visserijonderzoek (CVO) 04.006) - 74
    zeevisserij - marien milieu - mariene ecologie - visbestand - visserijbeleid - marine fisheries - marine environment - marine ecology - fishery resources - fishery policy
    Het WOT-programma 406 heeft betrekking op Wettelijke Onderzoeks Taken die betrekking hebben op het visserijonderzoek. Het onderzoeksprogramma WOT 406 loopt gedurende de periode 2002-2005 en is een voortzetting van WDT programma’s 212 en 339. Dit rapport bevat de rapportage en verantwoording van de activiteiten in 2003.
    Programma Wettelijke Onderzoek Taken Visserijonderzoek DLO-programma 406
    Beek, F.A. van - \ 2004
    IJmuiden : RIVO (CVO rapport / Stichting DLO, Centrum voor Visserijonderzoek (CVO) 04.026) - 62
    zeevisserij - visbestand - bijvangst - schaaldieren - monitoring - visserijbeleid - visserij - marine fisheries - fishery resources - bycatch - shellfish - monitoring - fishery policy - fisheries
    In het DLO-programma 406: “Wettelijke Onderzoek Taken Visserijonderzoek” worden een aantal taken uitgevoerd die betrekking hebben op de visserij. Het programma omvat een aantal uiteenlopende onderzoeksonderwerpen, met als belangrijkste gezamenlijk element “een vereist zijn op grond van enigerlei wettelijke regeling” en een daaruit voortvloeiende langjarige looptijd. Het programma bestrijkt de periode 2002-2005 en is een voortzetting van de DLO programma’s 212 (1994-1997) en 339 (1998-2001). In 2004 heeft een herijking van het programma plaatsgevonden door DWK.
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