July 24, 2025 — A newly released study by Oregon State University and NOAA Fisheries researchers shows that marine heat waves in increasing frequency are having an impact on the growth and maturation of black rockfish in Oregon and Washington.
“We do know that the occurrence of marine heatwaves is more often and more intense,” said Claire Rosemond, now a fisheries biologist at NOAA Fisheries’ Northwest Fisheries Science Center in Newport, Ore. “There are some monitored ocean indicators that can help us understand if the coming year would be warmer or cooler, but it is harder to predict how hot or how cold.”
Results of her dissertation while at OSU with fisheries biologist Melissa Head, also of the Northwest Fisheries Science Center, and Scott Heppell, a professor at OSU ‘s Department of Fisheries Wildlife and Conservation Sciences, were published on June 3 in the journal Ecological Applications.
The study investigated the impact of intense and less intense marine heatwaves on black rockfish reproduction and growth along the Pacific Coast between 2014 and 2021.
They found that while black rockfish exhibited elevated growth during intense marine heatwaves, their maturation was delayed. In fact, during intense marine heatwaves, maturation was postponed, reproductive success was lower by one third, and parasite prevalence in ovaries was nominally high.
Younger females were large at age during intense marine heatwaves, and throughout the last decade, growth rate coefficients were higher than what is typically expected for slower-growing fishes like rockfishes.