Rebuilding in the face of climate change

Decadal-scale climate variability and change can cause trends in oceanographic conditions that impact demographic rates. Rebuilding scenarios, therefore, developed assuming constant demographic rates may not be realistic. Winter flounder (Pseudopleuronectes americanus) is an important commercial and recreational species that has declined in the southern portion of its range despite reduced exploitation. Laboratory and mesocosm studies suggest that stock productivity is reduced under warmer conditions and that rebuilding to historical levels may not be possible. Our goal was to examine the rebuilding potential of winter flounder in the face of regional warming. We integrated winter temperature into a population model to estimate environmentally driven stock-recruitment parameters and projected the stock into the future under different climate and fishing scenarios. The inclusion of winter temperature had minor impacts on the estimates of current abundance, but provided greater understanding of the drivers of recruitment. Projections that included the environment suggest that rebuilding the stock to historical levels is unlikely. The integration of both fishing and the environment has the potential to provide more realistic expectations of future stock status. La variability et les changements climatiques decennaux peuvent produire des tendances dans les conditions oceanographiques qui influencent les taux demographiques. Aussi, les scenarios de reconstitution elabores en presumant des taux demographiques constants pourraient ne pas etre realistes. La plie rouge (Pseudopleuronectes americanus), une espece importante pour la peche commerciale et sportive, est en baisse dans la partie sud de son aire de repartition, malgre une reduction de son exploitation. Des etudes en laboratoire et en mesocosme donnent a penser que la productivity du stock diminue dans des conditions plus chaudes et que le retablissement des niveaux historiques pourrait ne pas etre possible. Notre objectif consistait a examiner le potentiel de reconstitution du stock de plie rouge etant donne le rechauffement regional. Nous avons incorpore la temperature hivernale dans un modele de population afin d'estimer les parametres de recrutement au stock modules par des facteurs ambiants et avons etabli des projections du stock pour differents scenarios climatiques et de peche. L'integration de la temperature hivernale a des effets mineurs sur les estimations de l'abondance actuelle, mais permet une meilleure comprehension des facteurs qui modulent le recrutement. Les projections qui integrent les conditions ambiantes indiqueraient que le retablissement des niveaux historiques du stock est improbable. L'integration de la peche et des conditions ambiantes pourrait produire des previsions plus realistes de l'etat futur du stock. [Traduit par la Redaction]
Introduction With the reauthorization of the Magnuson-Stevens Act, rebuilding plans were implemented in the United States to provide a legally binding time line to reduce overfishing (NOAA1996). For many species [...]