Behavioral responses of Atlantic cod to sea temperature changes

Ecology and Evolution

Carla Freitas¹  Esben Moland Olsen¹  Even Moland¹  Lorenzo Ciannelli² 

[1] Department of Natural Sciences, Faculty of Engineering and Science, University of Agder, Kristiansand, Norway;College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, Oregon

关键词: Acoustic telemetry;    climate change;    diel vertical migration;    Gadus morhua;    sea surface temperature;   

DOI  :  10.1002/ece3.1496

来源: Wiley

【 摘 要 】

Abstract

Understanding responses of marine species to temperature variability is essential to predict impacts of future climate change in the oceans. Most ectotherms are expected to adjust their behavior to avoid extreme temperatures and minimize acute changes in body temperature. However, measuring such behavioral plasticity in the wild is challenging. Combining 4 years of telemetry-derived behavioral data on juvenile and adult (30–80 cm) Atlantic cod (Gadus morhua), and in situ ocean temperature measurements, we found a significant effect of sea temperature on cod depth use and activity level in coastal Skagerrak. During summer, cod were found in deeper waters when sea surface temperature increased. Further, this effect of temperature was stronger on larger cod. Diel vertical migration, which consists in a nighttime rise to shallow feeding habitats, was stronger among smaller cod. As surface temperature increased beyond ~15°C, their vertical migration was limited to deeper waters. In addition to larger diel vertical migrations, smaller cod were more active and travelled larger distances compared to larger specimens. Cold temperatures during winter tended, however, to reduce the magnitude of diel vertical migrations, as well as the activity level and distance moved by those smaller individuals. Our findings suggest that future and ongoing rises in sea surface temperature may increasingly deprive cod in this region from shallow feeding areas during summer, which may be detrimental for local populations of the species.

【 授权许可】

CC BY   
© 2015 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.