These changes in the hatch cycle and early growth patterns persisted in years following the marine heat waves, which could have implications for the future of Gulf of Alaska Pacific cod, an economically and culturally significant species, said Jessica Miller of OSU's Coastal Oregon Marine Experiment Station at Hatfield Marine Science Center in Newport and the study's senior author.

Pacific cod, perhaps best known as the key ingredient in fish and chips, is the second largest commercial groundfish fishery off the coast of Alaska. The findings, which were just published in the journal Elementa: Science of the Anthropocene, could also have implications for future management of the fishery.

The researchers found that Pacific cod were hatching earlier during and after the 2014-2016 marine heat wave began, and those earlier hatches continued even when ocean temperatures cooled in 2017 and 2018. Monitoring programs in the future may also have to be redesigned, in terms of their timing or types of nets used, to account for changes in spawn timing and body size.