HMSC Research Seminar, Jan 19, 20231

Speaker: Zoe Almeida, Postdoctoral Scholar, COMES, Oregon State University’s Hatfield Marine Science Center

Topic: Warmer, earlier, faster: Cumulative effects of Gulf of Alaska heatwaves on the early life history of Pacific Cod 

Warming climates are creating unprecedented environmental conditions such as more frequent and intense marine heatwaves that directly impact individual phenology and growth. Understanding individual, in-situ phenological and growth responses to temperature is critical to predicting population and species responses to climate change. We quantified the relationships between temperature and hatch timing, size-at-age, and early-life growth in a population affected by recent marine heatwaves using daily otolith increments of Pacific Cod juveniles collected near Kodiak Island, Alaska, USA across 11 years "before" and "since" recent marine heatwaves. We found earlier hatching phenology since marine heatwaves, but only ~30% of the shift was due to the warmer temperatures experienced. Additionally, we found a change in temperature-dependent growth since marine heatwaves. Our results imply that factors other than just warmer temperatures such as other environmental conditions, previous experiences, and population composition likely contributed to the changes since marine heatwaves.