An Evaluation Of Recruitment Indices For Northeast Arctic Cod (Gadus Morhua L.) ...

No abstracts are to be cited without prior reference to the author.Indices of the abundance of Northeast Arctic cod (Gadus morhua L.) for various life stages were compared in order to determine the earliest stage at which year-class strength is established. The indices considered are: VP A estimates...

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Bibliographic Details
Main Authors: Helle, Kristin, Bogstad, Bjarte, Marshall, C. Tara, Michalsen, Kathrine, Ottersen, Geir, Pennington, Michael
Format: Conference Object
Language:unknown
Published: ASC 1999 2024
Subjects:
Online Access:https://dx.doi.org/10.17895/ices.pub.25637604
https://ices-library.figshare.com/articles/conference_contribution/An_Evaluation_Of_Recruitment_Indices_For_Northeast_Arctic_Cod_Gadus_Morhua_L_/25637604
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Summary:No abstracts are to be cited without prior reference to the author.Indices of the abundance of Northeast Arctic cod (Gadus morhua L.) for various life stages were compared in order to determine the earliest stage at which year-class strength is established. The indices considered are: VP A estimates of spawning stock biomass; an egg abundance index; an early juvenile (approximately three-months old) abundance index; 0-group (age four to five months) abundance indices; bottom trawl and acoustic survey abundance indices for one, two and three- year-old cod and VP A estimates of the abundance of three-year-old cod. Based on a regression analysis, the relative abundance of early juvenile cod was the first life stage that was correlated with their relative • abundance as three year olds. Since the correlation between the estimates of spawning stock biomass or total egg production and the relative abundance of three-year-old cod was weak, it is concluded that considerable yearly variation in mortality occurs ...