Temperature increase cause decreased densities and smaller fish

BYSTRÖM, PÄR; HEDSTRÖM, PER; HOTCHKISS, ERIN; RODRÍGUEZ, PATRICIA; KARLSSON, JAN

Portland

Congreso; ASLO Joint Aquatic Sciences Meeting; 2014

ASLO (Association for the Sciences of Limnology and Oceanography)

Temperature impacts all biota and ecosystems through the direct effects of temperature on primary producer to top consumer organisms? vital rates. Still, how this translates from the individual to the population and ecosystem level are poorly understood. Here, we study the effects of a temperature increase during summer on all trophic levels in large scale pond ecosystem experiment over 16 month including two growth seasons and fish (three spine sticklebacks) recruitment events. Increased temperature had no effect on whole ecosystem primary production. Fish population density and maximum size decreased with temperature whereas proportion of young and smaller-sized fish increased most likely due to an increase in metabolic demands to resource production. Our results suggests that for fish populations, global warming may increase competition, favor young and small size classes which in turn may destabilize population and community dynamics.