Reaction Norms For Age And Size At Maturation: Study Of The Long-Term Trend (1970-1998) For Georges Bank And Gulf Of Maine Cod Stocks ...

• Main Authors: Barot, S., Heino, M., O'brien, L., Dieckmann, U.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: ASC 2002 - Y - Theme session 2024
• Subjects: Fisheries and aquaculture; Pressures, impacts, conservation, and management; atlantic cod
• Online Access: https://dx.doi.org/10.17895/ices.pub.25443592.v1; https://ices-library.figshare.com/articles/conference_contribution/Reaction_Norms_For_Age_And_Size_At_Maturation_Study_Of_The_Long-Term_Trend_1970-1998_For_Georges_Bank_And_Gulf_Of_Maine_Cod_Stocks/25443592/1

No abstracts are to be cited without prior reference to the author.Average age and size at maturation have decreased in many commercially exploited fish stocks during the last few decades. This phenomenon could be either a direct phenotypic response to some environmental variation, or the evolutionary consequence of some selective pressure. Traditionally used maturation indices, i.e. the age and size at which 50% of individuals are mature, are not appropriate to assess the causes of changes in maturation because they are influenced, in addition to maturation per se, by growth and survival. To make up for this shortcoming, and to disentangle evolutionary changes and phenotypic plasticity, we use a reaction norm based approach. A method is presented to estimate the reaction norm for age and size at maturation from a type of data commonly gathered for the management of fisheries. This method is applied to data on Georges Bank and Gulf of Maine Atlantic cod stocks. Maturation reaction norms in these stocks have ...