April 9, 2021 — The following was released by NOAA Fisheries:
For a young Pacific cod, first feeding is a life-or-death moment. Cod larva are nourished by a yolk sac after they hatch. Once the yolk sac is depleted, they must find food within days in order to survive. If there is no prey available during that critical window for first feeding, young fish face starvation.
Warming Alaska waters are increasing the risk of prey mismatch and starvation for cod larvae, a new study finds.
NOAA Fisheries scientists collaborated with our partners to look at how temperature shifts affected first feeding Pacific cod larvae in two large ecosystems: the southeast Bering Sea and Gulf of Alaska. The models made predictions for 1998–2019, a period that encompassed warm and cool years, including a series of extreme heatwave events beginning in 2014.
“Warming can increase the metabolic demands of fish and shift the timing of their food production. So you have temperature unravelling the system, moving food around. And you have fish needing food now. When mismatched prey timing and increased metabolic demand line up, it can be pretty disastrous,” said Ben Laurel, NOAA Fisheries scientist at the Alaska Fisheries Science Center, who led the study. “The better we can understand and predict these effects, the more effectively we can manage them now and in the future.”