CLIMATE CHANGE LEADS TO EARLIER SEASONAL OCCURRENCE OF LARVAL FISHES IN THE SOUTHERN CALIFORNIA CURRENT

Abstract : Global warming has prompted an earlier arrival of spring in numerous ecosystems. It is uncertain whether such a change is occurring in the California Current Ecosystem, because this region is subject to decadal climate oscillations and regional climate models predict seasonal delays in upwelling. We investigated changes in larval phenology of 43 fish species sampled by California Cooperative Oceanic Fisheries Investigations between 1951-2008. Trends in monthly larval abundance were analyzed by decadally averaging data from quarterly surveys conducted in different months. Phenological shifts were quantified by anomalies in the central tendency (CT) of larval abundance. 39% of species displayed increasingly early peaks in larval abundance; 18% exhibited delayed phenology; the remainder did not show a secular trend. Species with offshore distributions that spawn during spring and summer were most likely to display advancing phenology. Myctophiformes, Stomiiformes, Perciformes, and Scorpaeniformes are spawning 10-20 days earlier on average than in the 1950s, while Pleuronectiformes and Argentiniformes are spawning 9-12 days later. An inverse relationship between year and SST CT indicated earlier warming of surface waters. A significant correlation was observed between SST CT and species exhibiting phenological changes. Species with a decadal trend towards earlier phenology also spawned early during El Niño. Species with delayed phenology or no decadal trend spawned later during El Niño possibly due to delayed upwelling. Fishes that are not adjusting their phenology were less likely to shift their geographic distribution in relation to environmental variables, implying they may have a reduced capacity to adapt to climate change.
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Communication dans un congrès
ClimECO2 International Summer School - Oceans, Marine Ecosystems, and Society facing Climate Change, Aug 2010, Brest, France
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http://hal.univ-brest.fr/hal-00502303
Contributeur : Ivo Grigorov <>
Soumis le : mardi 13 juillet 2010 - 17:00:01
Dernière modification le : mardi 13 juillet 2010 - 17:00:01

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  • HAL Id : hal-00502303, version 1

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Rebecca Asch, D. M. Jr. Checkley. CLIMATE CHANGE LEADS TO EARLIER SEASONAL OCCURRENCE OF LARVAL FISHES IN THE SOUTHERN CALIFORNIA CURRENT. ClimECO2 International Summer School - Oceans, Marine Ecosystems, and Society facing Climate Change, Aug 2010, Brest, France. 〈hal-00502303〉

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