As water temperatures rise, some fish are breeding earlier — and more often

Some small Alaska fish have made a big change in response to a warming climate — they are breeding earlier and, in some cases, twice a year, according to new research.

Five decades of monitoring at Lake Aleknagik in the Bristol Bay region revealed that, as ice breakup dates arrived earlier and water temperatures increased, the threespine stickleback living there produced their offspring earlier in the summer.