Higher annual temperatures in Alaska’s Bristol Bay have caused lakes and rivers to warm up earlier in spring, enhancing the growth of plankton that Young sockeye salmon eat. This fattens up the young salmons much quicker than before, so that they now migrate to sea a year earlier.

This series of events, described in a new study, does not necessarily mean that sockeyes benefit from global warming, because in the ocean they have to compete with increasing number of cultured sockeyes, making them stay in the ocean a year longer before returning to freshwater to spawn. Also, as all young fish now migrate to the sea at the same age (one year), the population is at risk if ocean conditions happen to be poor that year.

This report shows an example of the complicated ecological effects of global warming.

Read the full story: University of Washington
Scientific publication: Nature Ecology & Evolution