Determinate versus indeterminate fecundity in horse mackerel
Gordo, L. ; Costa, A. ; Abaunza, P. ; Lucio, P. ; Eltink, A.T.G.W. ; Figueiredo, I. - \ 2008
Fisheries Research 89 (2008)2. - ISSN 0165-7836 - p. 181 - 185.
saronikos gulf greece - trachurus-trachurus l - maturity - growth
No consensus has been reached yet on the question whether horse mackerel has a determinate or an indeterminate fecundity. This problem has been discussed based on three main criteria: (a) oocyte size frequency distribution, (b) the number of yolked oocytes in the ovary and (c) atresia. The analysis of the oocyte size frequency distribution showed that no distinct hiatus could be observed between pre-vitellogenic and vitellogenic oocytes. The number of yolked oocytes in the ovary was found higher in imminent spawning ovaries than in the pre-spawing, while a greater number of late yolked oocytes was found in recently spawning ovaries than in the pre-spawning. High incidence of atresia was also found in recently spawning (6–22%) and spent ovaries (over 29%). Those findings indicate that horse mackerel has most probably an indeterminate fecundity
Egg and larval distributions of seven fish species in north-east Atlantic waters
Ibaibarriaga, L. ; Irigoien, X. ; Santos, M. ; Eltink, A.T.G.W. - \ 2007
Fisheries Oceanography 16 (2007)3. - ISSN 1054-6006 - p. 284 - 293.
gulf-stream - shelf-break - sea - mackerel - recruitment - abundance - climate - biscay - bay - connection
The distribution of egg and larvae of mackerel, horse mackerel, sardine, hake, megrim, blue whiting and anchovy along the European Atlantic waters (south Portugal to Scotland) during 1998 is described. Time of the year, sea surface temperature and bottom depth are used to define the spawning habitat of the different species. Mackerel, horse mackerel, and sardine eggs and larvae presented the widest distribution, whereas megrim and anchovy showed a limited distribution, restricted to the Celtic Sea and the Bay of Biscay respectively. Correspondingly mackerel, horse mackerel and sardine showed the highest aggregation indices. Blue whiting larvae were found at the lowest temperatures, whereas anchovy eggs and larvae were found in the warmest waters. The analysis is a basis for evaluation of ongoing changes in the pelagic ecosystem of the north-east Atlantic.
The spray technique: a new method for an efficient sepation of fish eggs from plankton
Eltink, A.T.G.W. - \ 2007
Journal of Plankton Research 29 (2007)10. - ISSN 0142-7873 - p. 871 - 880.
A fast automatic new method, the "spray technique", for the separation of fish eggs from plankton samples has been developed; each egg-sorting procedure requires less than 3 min (removal of zero up to hundreds of eggs). A targeted accuracy can be achieved by repeating the procedure. The spray method can be easily applied onboard research vessels and it appears to cope well with different plankton compositions. Tests suggest that the method is 25, 60 and 110 times faster than the traditional manual method when using samples with low, medium and high plankton content. Sorted egg fractions contain less contamination by plankton particles than with the manual method. This new method is much less prone to human error and can be standardised. However, as plankton samples vary, it is crucial to estimate regularly the accuracy of the sorting. The method should only be used with standard operating procedures and pre-determined accuracy targets. Accuracy can be estimated afterwards by sorting thoroughly; checking whether any eggs had been left.
|Handboek marktbemonstering (versie werkjaar 2006)
Verver, S.W. ; Eltink, A.T.G.W. ; Bolle, L.J. ; Beintema, J.J. ; Groeneveld, K. ; Os-Koomen, E. van; Rink, G.J. ; Schaap, L.A. ; Vries, M. de; Willigen, J.A. van - \ 2006
IJmuiden : RIVO (CVO rapport 06.001) - 83 p.
Market Sampling of Landings of Commercial fish Species in The Netherlands in 2003
Verver, S.W. ; Eltink, A.T.G.W. ; Poos, J.J. - \ 2006
IJmuiden : RIVO (CVO report 06.002) - 11
visserij - visserijbeheer - visstand - visbestand - bemonsteren - monitoring - visvangsten - fisheries - fishery management - fish stocks - fishery resources - sampling - monitoring - fish catches
The biological market-sampling programme for marine fish species provides, together with the information from the assessment surveys by research vessels, the information which is essential for relating changes in the fish stocks to changes in the fishery. The market sampling program in the Netherlands comprises the collection of fish samples from commercial catches, the analysis of these samples (estimation of length, weight, sex, sexual maturity and age), and the conversion of the national catches in tonnes to age compositions in numbers together with the additional information on mean weight at age, mean length at age. In a later stage, this information by country is combined to figures representative for the whole fish stock. These combined international data, collected over many years, form the basis for the analysis of population dynamics and for providing biological advice on fishery management.
Horse mackerel fecundity in relation to lipid content
Damme, C.J.G. van; Dransfeld, L. ; Eltink, A.T.G.W. ; Krueger-Johnsen, M. ; Perez, J.R. ; Ulleweit, J. ; Witthames, P.R. - \ 2005
Copenhagen : ICES (ICES CM 2005/Q:03) - 17 p.
During the 2004 mackerel and horse mackerel triennial egg survey fecundity of horse mackerel (Trachurus trachurus L.) was estimated using a new gravimetric and image analysis system. The fecundity estimates and mean oocyte diameters showed great variation between and within different institutes. Horse mackerel fecundity increased during the spawning season and showed no decline at the end of the spawning season. This indicates that this species is likely to be an indeterminate spawner. The lipid content was estimated from whole horse mackerel collected during the three months prior and during the spawning season. Lipid content rapidly decreased during the period of ovary development prior to the onset of spawning, but remained rather constant during spawning. A relationship between fecundity and lipid content could not be found. A time series of lipid content estimates collected annually or triennially might provide an index for changes in fecundity over time. Sampling needs to be carried out prior to the onset of spawning, when fat content is at its highest. Annual stomach content estimates collected in successive years might provide an index for food availability and feeding success. The stomach analysis carried out in 2004 indicated that horse mackerel was feeding only at a low level during the spawning period
|Handboek marktbemonstering versie 2004.1
Eltink, A.T.G.W. ; Bolle, L.J. ; Beintema, J.J. ; Groeneveld, K. ; Rink, G.J. ; Schaap, L.A. ; Verver, S.W. ; Vries, M. de; Willigen, J.A. van - \ 2004
RIVO Biologie en Ecologie (CVO rapport 04.027) - 85 p.
|Microverspreiding per maand van Nederlandse vangsten in Europese wateren: horsmakreel, haring, makreel, blauwe wijting en grote zilversmelt in 2000 - 2002
Eltink, A.T.G.W. ; Verver, S.W. - \ 2004
IJmuiden : RIVO (Rapport / RIVO 04.007) - 66 p.
Growth and reproduction of horse mackerel, Trachurus trachurus (carangidae)
Abaunza, P. ; Gordo, L. ; Karlou-Riga, C. ; Murta, A. ; Eltink, A.T.G.W. ; Garcia Santamaria, M.T. ; Zimmermann, C. - \ 2003
Reviews in Fish Biology and Fisheries 13 (2003)1. - ISSN 0960-3166 - p. 27 - 61.
saronikos gulf greece - fish otoliths - spawning frequency - north-sea - fundulus-heteroclitus - gastric evacuation - back-calculation - sexual-maturity - batch fecundity - oocyte growth
There is a broad knowledge of the growth and reproduction of Trachurus trachurus, although important gaps still exist. Horse mackerel are a long-lived species, reaching up to 40 years of age. They have isometric growth, although the alometric parameter b may vary throughout the year and in relation to latitude. Growth to age 3 is rapid compared to slower growth later in life. Phenomena of density dependent growth have been observed in the northeast Atlantic. Horse mackerel are an asynchronous species. The following stages of atresia have been validated in horse mackerel: alpha, beta, and delta. The transition in females from the spawning state to post spawning is very fast. The spawning fraction in horse mackerel is estimated to be between 8.3 nd 20.9&Eth;Horse mackerel have a long spawning season (up to 8 months), which varies according to geography. Length at first maturity is between 16 and 25 cm, most commonly around 21 cm. Males mature at a slightly smaller length than females. The age at first maturity for females has been estimated to range from 2 to 4 years, depending on the geography. Batch fecundity has been estimated to range between 172¿209 oocytes per gram-female-weight. Female spawning lasts between 65 and 94 days. An individual female can release from 5 to 16 batches during the spawning period. The estimated potential annual relative fecundity ranges from 1040 to 3280 oocytes per gram-female-weight
Market Sampling of Landings of Commercial Fish Species in the Netherlands in 2002
Vries, M. de; Rink, G.J. ; Groeneveld, K. ; Beintema, J.J. ; Poos, J.J. ; Eltink, A.T.G.W. - \ 2003
IJmuiden : RIVO (Internal RIVO report / Netherlands Institute for Fisheries Research no. 03.012) - 14
visserij - visserijbeheer - analyse - bemonsteren - biologie - monitoring - visvangsten - visstand - fisheries - fishery management - analysis - sampling - biology - monitoring - fish catches - fish stocks
This report contains information on the biological sampling for the market sampling program: which species are sampled, how they were caught, when and where the samples are taken (date and position), how many fish have been measured, how many fish have been aged, etc. The report gives an overview of all the biological sampling activities in 2002 by RIVO on the landings of the commercial important species of herring, mackerel, horse mackerel, blue whiting, greater argentine, sole, plaice, turbot, brill, dab, lemon sole, cod, whiting, Norway lobster and four different species of rays from all ICES areas. This biological sampling took place on landings by both the Dutch fleet as well as foreign fleets landing in the Netherlands. In addition this report contains information on the biological samples collected during research vessel surveys and discard trips both on commercial and non-commercial species.
Bolle, L. ; Eltink, G. ; Schaap, L. ; Vries, M. de; Bakker, K. ; Groot, P. de; Rink, G.J. - \ 2003
IJmuiden : RIVO (CVO rapport 03.010) - 73 p.
|Market Sampling of Dutch Landings of Commercial Species (MARSAM-3)sampling year 2001 - final report
Rink, G.J. ; Groeneveld, K. ; Beintema, J.J. ; Vries, M. de; Eltink, A.T.G.W. - \ 2002
IJmuiden : RIVO (RIVO report C011/02) - 17 p.
Improvements in the quality of the basic horse mackerel age data during the last 20 years
Eltink, A. - \ 2001
|Toestandsbeoordeling en biologische adviezen makreel en horsmakreel: TAC's uitbreiden over hele noordoost Atlantisch gebied
Eltink, A.T.G.W. - \ 2000
Visserijnieuws 20 (2000)49. - ISSN 1380-5061 - p. 8 - 8.
|Survey Tridens in de Noorse Zee: schatting bestand sloeharing
Eltink, A.T.G.W. - \ 2000
Visserijnieuws 20 (2000)17. - ISSN 1380-5061 - p. 5 - 5.
|Market Sampling of Dutch Landings of commercial Species (MARSAM -2).(sampling year 1998)
Groeneveld, K. ; Rink, G.J. ; Beitema, J.J. ; Boeek, F.A. van; Eltink, A.T.W.G. - \ 1999
Unknown Publisher (REPORT C005/99)
|Market sampling of Dutch landings of commercial species (MARSAM) final report
Eltink, G. - \ 1998
Unknown Publisher (RAPPORT C017/98)
|Echo Surveys for Herring in the North Sea and West of Scotland (ECHOHER) 95/074 Final report, Final report 1 January 1996 - 31 December 1997, Part 1, Part Annex 1-6
Eltink, G. - \ 1998
Unknown Publisher (REPORT C007/98)
|Market Sampling of Dutch Landings of Commercial Species (MARSAM) (sampling year 1996, Interim Report)
Beintema, J.J. ; Groeneveld, K. ; Rink, G.J. ; Eltink, A.T.W.G. ; Beek, F.A. van - \ 1997
Unknown Publisher (RIVO-DLO Report C047/97)
|Horse Mackerel Otolith Exchange in 1996
Eltink, A. - \ 1997