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.

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    We will mail you new results for this query: wurpublikatie/titelbeschrijving/classificatie/trefwoord/cab/engels==pleuronectiformes
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Fleet dynamics in a changing policy environment
Batsleer, J. - \ 2016
Wageningen University. Promotor(en): Adriaan Rijnsdorp, co-promotor(en): Jan Jaap Poos. - Wageningen : Wageningen University - ISBN 9789462579521 - 171
fleet dynamics - fisheries - fishery policy - fishery management - sustainability - pleuronectiformes - vlootdynamica - visserij - visserijbeleid - visserijbeheer - duurzaamheid (sustainability) - pleuronectiformes

The European Common Fisheries Policy has received much criticism. In the first place for failing to implement effective management measures aimed at rebuilding and maintaining fish stocks at a sustainable level. In addition, it is said current fisheries policy fails to integrate the wider ecosystem effects of fishing into policy making, such as reducing pressure on non-target species and habitats. Especially discarding (i.e. throwing back unwanted catches at sea) in commercial fisheries has received an increased amount of negative attention. Public campaigns stressed discarding is a wasteful and disruptive practice as natural resources are extracted from the ecosystem only to be thrown back to sea dead. In response, the European Commission agreed to enforce a discard ban for European fisheries, obliging all European fishing vessels to retain and land their entire catch, including small sized individuals, of all species subject to quota management.

This thesis explores how management measures can mitigate the adverse effects of fishing to support the development of an ecosystem-based approach to fisheries management. I evaluate how fleet dynamics, i.e. the decision of individual skippers on when and where to fish, while competing for similar resources, may influence the performance of management measures. In particular the thesis focusses on how location choice and discard decisions made by individual fishers in a mixed fishery are influenced by management, resource distribution and technological innovations. Using a generic dynamic state variable model (DSVM), specific applications are built to address the behavioural dynamics for the Dutch North Sea flatfish fisheries and the French mixed demersal fisheries in the Channel in response to new management regulations and economic opportunities.

The first research chapter of this thesis (Chapter 2) explores how a combination of quota management with a discard ban may improve the regulation of fishing mortality for a depleted stock that is exploited in a mixed fishery. Our finding show that under a discard ban, when properly enforced, individual fishers reallocate fishing effort away from areas and weeks with high catch rates of the quota constrained species, reducing over-quota discarding and thus contributes to the conservation of vulnerable species. However, discard reduction measures which coincide with a reduction in the economic performance of the fishery may jeopardise compliance as fishers may trade-off economic gains of non-compliance against the costs.

Fishers will discard marketable fish when quota are exhausted (over-quota discarding) or by trying to optimize their economic return by discarding size or age classes with the lowest economic value (high-grading). In chapter 3 observations of over-quota discarding and high-grading are reviewed to gain insight in the conditions under which discard decisions may occur. The review suggest that high-grading occurs under different management systems for a large variety of fisheries worldwide. In addition, outcomes of the simulation model illustrate fishers have the ability to strategically plan their fishing activities to optimize the composition of their catch taking account of the availability of quota and seasonal price variations. As a result, the size composition of the high-graded catch differs from the landed catch. Difficulties in accounting for this difference may undermine the accuracy of the stock assessments and quality of scientific advice.

Chapter 4 addresses the question how a ban on discarding may promote the transition towards more selective fishing gears. Model results suggest that under a discard ban, fishing activities are restricted and reallocated away from areas and weeks of high catches of small fish constrained by quota. Activities are allocated to areas and weeks where a maximum revenue can be realised landing other species and economically more valuable length classes of the quota restricted species. When using more selective fishing gear, fishing activities will be less restricted. Fewer small fish are landed which would otherwise be counted against the quota, fetching a low price and reduce the economic value of the landings. Hence, there is an economic advantage and fishers can continue fishing for a longer period of time, including areas where a higher density of small fish as well as more economically valuable fish co-occur. As such, if properly enforced, a discard ban can incentivise the use of more selective gear to reduce the catch of undersized fish.

Trawl fisheries targeting demersal fish and shellfish cause mortality on target and non-target species, but impact benthic ecosystems. Fisheries managers mainly resort to technical management measures, such as gear restrictions or spatial measures to mitigate these impacts. Chapter 5 explores the potential of a habitat credit system as an alternative management approach to achieve sustainable exploitation of target species while minimizing the impact on the benthic ecosystem. Results show that a habitat credit system has the potential to reduce the benthic impact and maintain profitable fisheries as vessels can adjust their behaviour by reallocating fishing activities to make optimal use of the available credits.

Fishers can adapt and change their behaviour in relation to imposed constraints, which can lead to unintended and unexpected consequences of fisheries management. To date, the effect of behavioural adaptations of individual fishers on the success of fisheries management is often overlooked by policymakers. The models developed in this thesis provide a strong basis to explore possible unexpected effects of management measures resulting from the adaptive behaviour of fishers to these measures. Outcomes of this thesis draw attention to the importance of making fleet dynamics an integral part of fisheries management and the need to develop innovative analytical methodologies which deliver sufficiently robust insights into complex socioeconomic and ecosystem issues to improve the basis of decision making.

VIP Praktijknetwerk Netinnovatie Zuid
Marlen, B. van; Rink, G.J. ; Vandenberghe, C. - \ 2016
IJmuiden : IMARES (Rapport / IMARES C147/14) - 77 p.
visserij - duurzaamheid (sustainability) - pleuronectiformes - netten - noordzee - fisheries - sustainability - nets - north sea
Het VIP project Praktijknetwerk Netinnovatie Zuid beoogde een bijdrage te leveren aan een meer duurzame kottervisserij op platvis op zuidelijke bestekken in de Noordzee door het ontwikkelen van nieuwe netten met een lager brandstofverbruik, en minder netslijtage, bijvangsten en discards.
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 p.
pleuronectiformes - overleving - discards - zeevisserij - visserijbeheer - nederland - survival - marine fisheries - fishery management - netherlands
Vissen in de 12-mijlszone : inzetverandering visserij na introductie puls
Turenhout, M.N.J. ; Hamon, K.G. - \ 2015
Wageningen : LEI Wageningen UR (Nota / LEI 2015-100) - 12
pulsvisserij - pleuronectiformes - boomkorvisserij - visserijbeheer - kustwateren - noordzee - pulse trawling - beam trawling - fishery management - coastal water - north sea
Door de introductie van puls-techniek lijkt een ruimtelijke verplaatsing van de kottervisserij plaats te vinden (door economische overwegingen van vissers) naar de kustwateren (12-mijlszone). Door de efficiëntere tongvangsten lijkt het niet meer noodzakelijk om ver uit de kust te vissen. Deze verschuiving kan mogelijke risico’s met zich meebrengen door hogere visintensiteit in het kustgebied. Door het Ministerie van EZ is aan LEI Wageningen UR gevraagd om een eventuele verschuiving van de platvisvisserij naar de kustzone (12-mijlszone) in beeld te brengen aan de hand van een QuickScan. Het doel van dit onderzoek is: Een goed beeld geven van de mogelijke toename van inzet (en de daarbij behorende consequenties) van de platvisvisserij in de 12-mijlszone bij de introductie van visserij met puls-techniek.
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 - 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.
Flatfish pulse fishing: Research results and knowledge gaps II
Quirijns, F.J. ; Strietman, W.J. ; Marlen, B. van; Rasenberg, M.M.M. ; Smith, S.R. - \ 2015
IJmuiden : IMARES (Report / IMARES Wageningen UR C091/15) - 39
pulsvisserij - vismethoden - elektrische behandeling - visvangsten - kennismodellering - pleuronectiformes - pulse trawling - fishing methods - electrical treatment - fish catches - knowledge modeling
The aim of this report is to present a simple and clear overview of the knowledge currently available about catches (landings and discards) of pulse fishing gears in comparison with conventional fishing gears and the effects of these new gears on the marine ecosystem and to identify gaps in knowledge. Comments are also made on management issues of electric pulse fishing. The pulse technique is applied in both the flatfish and shrimp fishery. This report focuses only on the pulse fishery targeting flatfish.
Industrial survey for associated species: Results of a pilot-year
Reijden, K.J. van der; Poos, J.J. ; Chen, C. ; Os-Koomen, E. van; Dijkman Dulkes, H.J.A. ; Pasterkamp, T.L. ; Rasenberg, M.M.M. - \ 2015
IJmuiden : IMARES (Report / IMARES Wageningen UR C036/15) - 25
visserijbeheer - visbestand - beoordeling - vergelijkend onderzoek - wetenschappelijk onderzoek - visserijbeleid - eu regelingen - noordzee - tarbot - scophthalmus rhombus - pleuronectiformes - boomkorvisserij - fishery management - fishery resources - assessment - comparative research - scientific research - fishery policy - eu regulations - north sea - turbot - beam trawling
To increase scientific knowledge and stimulate discussion on management of data-limited species, Ekofish Group B.V., the North Sea Foundation (NSF) and IMARES started a research project. This project consisted of two phases. In the first phase, IMARES and NSF performed a literature study on the constrains in management and biological knowledge for species selected by Ekofish. After phase one, Ekofish Group B.V. requested IMARES to set up an industrial survey to gather more information on turbot, brill and lemon sole. A pilot-survey was designed and performed for these species to test whether an industrial survey is feasible and valuable for biological knowledge and if so, how this survey should be designed. To test the design of the survey, research will be done on the haul duration and mesh size. To examine the added value of the pilot survey, results are compared with the BTS. In this report, the results of this pilot survey are presented and answer will be given to the following research question: “Is an industrial survey for turbot, bill and lemon sole feasible and does it increase knowledge with respect to scientific surveys?”
Pulswing. Ontwikkeling van een vistuig voor platvis waarin pulstechniek met de SumWing is gecombineerd
Taal, C. ; Klok, A.J. - \ 2014
Den Haag : LEI (Rapport / LEI 2014-039) - 46
pleuronectiformes - vissersschepen - vistuig - boomkorvisserij - pulsvisserij - innovaties - milieueffect - brandstofverbruik - kosten-batenanalyse - fishing vessels - fishing gear - beam trawling - pulse trawling - innovations - environmental impact - fuel consumption - cost benefit analysis
By integration of pulse-technique in SumWing gear (“flat beam”) a new, working and marketable pulsewing fishing gear model has been developed. This as an alternative gear for beam trawl, specifically suitable for catching sole. Economic results of pulsewing seems to be better than the results of using beam trawl and SumWing and impact on ecology is considerably less. Compared to beam trawl, less fish was landed and a lower revenues were realised per day at sea, but less fuel consumption and as a result of that lower costs shows better margins to pay other costs. Fuel consumption related to landed fish (per kilogram) shows also lower figures. In this report just calculations are made for fishing vessels of 2.000 hp. Till 2011 no smaller vessels (Eurocutters, 300 hp) were active with pulsewing fishing gear.
Data evaluation of data limited stocks: Horse mackerel, Seabass, Greater Silver Smelt, Turbot and Brill
Hammen, T. van der; Poos, J.J. ; Overzee, H.M.J. van; Heessen, H.J.L. ; Rijnsdorp, A.D. - \ 2014
IJmuiden : IMARES (Report / IMARES Wageningen UR C166/13) - 84
trachurus trachurus - osmerus - zeebaars - tarbot - scophthalmus rhombus - visbestand - pleuronectiformes - visstand - visserij - sea bass - turbot - fishery resources - fish stocks - fisheries
Several commercially important fish stocks are classified by ICES (International Council for the Exploration of the Sea) as “data limited” stocks, which are stocks for which the data are insufficient to perform a full analytical assessment and forecast. In this report available data and literature on North Sea horse mackerel, greater silver smelt, seabass, turbot and brill are analysed. The data in this report may be used in future for catch advice by ICES.
Pulskor lucratief voor vissers
Marlen, Bob van - \ 2014
pulse trawling - beam trawling - pleuronectiformes - bycatch - fuel consumption
Resultaten boomkorsurvey 2013: BTS met onderzoeksvaartuigen Isis en Tridens (interview met Ingeborg de Boois)
Boois, I.J. de - \ 2013
Visserijnieuws 33 (2013)51/52. - ISSN 1380-5061 - p. 5 - 5.
boomkorvisserij - schol - tong (vis) - pleuronectiformes - visbestand - wetenschappelijk onderzoek - beam trawling - plaice - dover soles - fishery resources - scientific research
Van begin augustus tot half september heeft IMARES de boomkorsurvey (BTS) uitgevoerd met de onderzoeksschepen Isis en Tridens. Op 29 maart 2014 wordt een bijeenkomst georganiseerd voor geinteresseerden, waar de resultaten van zowel de BTS als de bedrijfssurvey gepresenteerd worden. De BTS wordt uitgevoerd door IMARES, de bedrijfssurvey samen met IMARES diir de kottersector. Ingeborg de Boois van IMARES geeft op basis van de jongste rapporten alvast inzicht in de BTS.
Staandwantvisserij op platvis en kabeljauw
Quirijns, F.J. - \ 2013
IMARES / Kenniskringen Visserij
tong (vis) - kabeljauw - pleuronectiformes - vismethoden - netten - visserij - duurzaamheid (sustainability) - dover soles - cod - fishing methods - nets - fisheries - sustainability
In de staandwantvisserij gebruiken vissers netten die verankerd zijn op de bodem. De staandwantvisserij is een passieve visserij; vissen worden gevangen doordat ze verstrikt raken als ze erdoorheen proberen te zwemmen. Deze informatiebrochure gaat over de staandwantvisserij gericht op tong en de staandwantvisserij met grotere mazen gericht op kabeljauw of platvis. Er zijn ongeveer 60 (kleine) vaartuigen die zich bezighouden met deze visserijen.
Platvis pulsvisserij: resultaten onderzoek en kennisleemtes
Quirijns, F.J. ; Strietman, W.J. ; Marlen, B. van; Rasenberg, M.M.M. - \ 2013
IJmuiden : IMARES (Rapport / IMARES C193/13) - 24
pulsvisserij - pleuronectiformes - visvangsten - discards - mariene ecologie - aquatische ecosystemen - kooldioxide - emissie - visserijbeheer - kennis - pulse trawling - fish catches - marine ecology - aquatic ecosystems - carbon dioxide - emission - fishery management - knowledge
Knowledge about the effects of pulse fishing is spread out over various reports and policy documents; a complete and accessible overview of knowledge is lacking. Pulse fishing is relatively new: in this fishery, fish are caught by means of electric pulses. Those pulses cause muscle contractions in the fish, resulting in them being released from the sea bottom and caught in the net. Because the pulse technique is relatively new and because electric fishing is not permitted in Europe, the development of this fishery brings up a lot of questions. the fishery study group Pulse and SumWing (part of the fishery study group Flatfish) asked IMARES and LEI to make a summary of the available knowledge on the effects of pulse fihing and lacking knowledge. This report summarises effects on landings and discards, effects on the ecosystem, management of the fishery and CO2 emission. At the end of the report, the authors give an overview of knowledge gaps.
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
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.
The KB WOT Fisheries Programme carried out in 2012
Damme, C.J.G. van; Beek, F.A. van - \ 2013
IJmuiden : Centrum voor Visserijonderzoek (CVO report 13.005) - 54
visserij - onderzoeksprojecten - monitoring - visserijbeheer - visstand - soorten - pleuronectiformes - mariene ecologie - kennisoverdracht - fisheries - research projects - fishery management - fish stocks - species - marine ecology - knowledge transfer
Het KennisBasis programma voor Visserijonderzoek onderhoudt en ontwikkelt de expertise, die nodig is om de wettelijke verplichtingen van Nederland op 't gebied van visserij monitoring en advies uit te voeren. Het KB WOT-programma wordt jaarlijks vastgesteld en gepositioneerd rond een aantal thema's In 2012 waren deze thema's: ecosysteembenadering van visserijbeheer en vis-descriptoren in de KRM, MSY beheersdoelstellingen voor Noordzee platvis, onderhoud van expertise en ontwikkeling en uitwisseling van kennis in internationaal verband. Er zijn 14 projecten uitgevoerd in 2012.
Tweede jaar bedrijfssurvey van start : UK 45 en OD 1 doen wetenschappelijke trekken
Rasenberg, M.M.M. - \ 2012
Visserijnieuws 32 (2012)32. - ISSN 1380-5061 - p. 2 - 2.
visstand - visbestand - vis vangen - boomkorvisserij - pulsvisserij - pleuronectiformes - wetenschappelijk onderzoek - fish stocks - fishery resources - fishing - beam trawling - pulse trawling - scientific research
In 2012 wordt voor de tweede keer de bedrijfssurvey uitgevoerd. Twee commerciele kotters (UK 45 en OD 1) zullen tijdens de jaarlijkse boomkorsurvey (BTS) in aanvulling op de onderzoeksschepen Isis en Tridens wetenschappelijke trekken doen om een beeld te krijgen van veranderingen in de tong- en scholstand.
Ontwikkelingen van vis en visserij in de Nederlandse Waddenzee
Tulp, I.Y.M. ; Walker, P. ; Bolle, L.J. - \ 2012
De Levende Natuur 113 (2012)3. - ISSN 0024-1520 - p. 89 - 95.
visbestand - visserij - demersale visserij - pleuronectiformes - visserijbeleid - garnalen - bodemfauna - waddenzee - fishery resources - fisheries - demersal fisheries - pleuronectiformes - fishery policy - shrimps - soil fauna - wadden sea
Voor veel vissoorten is de Waddenzee een belangrijk opgroeigebied. Voor veel andere soorten vormt de ondiepe, relatief voedselrijke Waddenzee een belangrijk leefgebied. Ze trekken er door heen, brengen er een deel van het jaar of hun hele leven door. Maar hoe is het eigenlijk gesteld met de vis in de Waddenzee? Een gebied dat tevens intensief gebruikt wordt door de visserij.
Pulsvissen rendabel en milieuvriendelijker
Taal, C. - \ 2012
Kennis Online 9 (2012)april. - p. 6 - 6.
pulsvisserij - vismethoden - visserij - pleuronectiformes - aquatisch milieu - pulse trawling - fishing methods - fisheries - aquatic environment
Onderzoek van IMARES, onderdeel van Wageningen UR, laat zien dat het vissen op platvis met pulsen in plaats van wekkerkettingen het bodemleven met de helft minder verstoort. Ook is het beter voor de portemonnee van de vissers.
Pulsvisserij overzicht onderzoek : platvis
Marlen, Bob van - \ 2012
pulse trawling - shrimps - pleuronectiformes - fish catches - fishing methods - research
Report of the Workshop on the identification of clupeoid, flatfish, gadoids and other fish larvae (WKIDFL)
Imares, - \ 2011
IJmuiden : IMARES (ICES WKIDFL report 2011)
conferenties - larven - vis - dieridentificatiesystemen - dieridentificatie - identificatie - overeenkomsten - pleuronectiformes - conferences - larvae - fish - animal identification systems - animal identification - identification - agreements
The Workshop on the Identification of clupeoid, flatfish, gadoid and other fish larvae (WKIDFL) met from 5 to 9 September 2011 in IJmuiden, The Netherlands, to calibrate fish larvae identification. The meeting was chaired by Cindy van Damme, The Neth-erlands, and Matthias Kloppmann, Germany. In total 17 persons representing 10 in-stitutes from 8 countries participated in the workshop. The majority of the time at the workshop was spent identifying fish larvae. The re-sults promoted discussion and highlighted specific problem areas. These discussions led to the further development of standard keys and larval identification characteris-tic tables.
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