dc.contributor.author | Kvalsund, Merete | |
dc.contributor.author | Marshall, C. Tara | |
dc.date.accessioned | 2012-10-10T21:20:50Z | |
dc.date.available | 2012-10-10T21:20:50Z | |
dc.date.issued | 1999 | |
dc.identifier.citation | This report is not to be cited without prior reference to the authors | no_NO |
dc.identifier.uri | http://hdl.handle.net/11250/105923 | |
dc.description.abstract | Spawner biomass (SB) is often assumed to be proportional to total egg production (TEP) by
fish stocks. Recent studies suggest that this assumption may not be valid, particularly when
the physiological condition of fish varies. This study used Monte Carlo techniques to simulate
the relationship between SB and TEP for Northcast Arctic cod (Gadus morhua). In the first
simulation exercise, reproductive traits reflecting condition (length-specific maturity, weight
and fecundity) were varied according to food abundance (capelin biomass) while the size
composition (numbers at length) was held constant. In the second exercise, the size
composition, as described by the modal length of spawners, was varied and condition was
held constant. In the final exercise, condition and size composition were varied
simultaneously. The first exercise indicated that variation in TEP was not constant but
increased as the SB increased. The second exercise showed that, for a given SB, TEP
increased with increasing modallength of spawners. Comparing the results of the first and
second exercise showed that food-dependent variation in condition introduced greater
variability into the relationship between SB and TEP than did shifting the size composition.
When condition and size composition were varied simultaneously, as would be expected in
wild stocks, TEP exhibited approximately 4-fold level of variation at any given SB. | no_NO |
dc.language.iso | eng | no_NO |
dc.publisher | ICES | no_NO |
dc.relation.ispartofseries | ICES CM Documents;1999/Y:6 | |
dc.subject | cod | no_NO |
dc.subject | torsk | no_NO |
dc.subject | biomass | no_NO |
dc.subject | biomasse | no_NO |
dc.subject | egg production | no_NO |
dc.subject | eggproduksjon | no_NO |
dc.title | Condition and size composition effects on the simulated relationship between spawner biomass and total egg production for Northeast Arctic cod (Gadus morhua L.) | no_NO |
dc.type | Working paper | no_NO |
dc.subject.nsi | VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 | no_NO |
dc.subject.nsi | VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Fish health: 923 | no_NO |
dc.source.pagenumber | 10 s. | no_NO |