New study paints gloomy picture of climate change's impact on commercial fishing (2025)

A new study of some of California’s most commercially significant aquatic species paints a grim picture for the future of the state’s fishing industry under the growing threat of climate change.

The study, compiled by a host of researchers including federal and state scientists as well as researchers from UC Santa Cruz and UC Davis, looked at 34 aquatic species in an attempt to gauge how each would fare under predicted climate change scenarios.

Among the species studied were Dungeness crab, red abalone, Pacific herring, Pismo clams, pink shrimp, Pacific bonito and California spiny lobster. The group ranked each by their level of vulnerability to changing environmental conditions.

“The most striking thing that we found is that among the species that were ranked as the most highly vulnerable happened to also be some of California’s economically valuable and culturally important species," said Mikaela Provost, assistant professor of fisheries ecology at UC Davis and co-author of the study.

California’s oceans are highly productive due to seasonal upwelling which keeps water temperatures cool and filled with nutrients. But models of future conditions forecast disruption through rising temperatures, deoxygenation and potential changes in circulation.

Some of the study’s most dire findings are especially concerning to Bay Area seafood lovers. Three of the species ranked as highly vulnerable were Dungeness crab, Pacific herring and red abalone.

In the case of Dungeness crab, the researchers found rising instances of ocean acidification — a rise in ocean acid levels due to carbon dioxide emissions — could eventually threaten their population, which contributes more than $80 million a year to the California seafood industry.

“They have this exoskeleton that makes them more vulnerable to ocean acidification, which is predicted to happen with climate change," Provost said.

Both Pacific herring and red abalone, which have faced crisis in recent years, also ranked as highly vulnerable. The San Francisco Bay’s once-bountiful Pacific herring fishery dropped off precipitously around 2015, an event blamed on overfishing and unfavorable ocean conditions. Their numbers have never fully rebounded.

The state closed the fishery for red abalone five years ago due to a population decline also blamed on overfishing but also because of the dwindling kelp forests which they rely. Scientists also connected their decline to climate change after starfish developed a fatal disease which in turn allowed the proliferation of purple sea urchins, which devastated abalone-friendly kelp beds along the North coast.

“So the overarching theme is that there will be big changes in California fisheries in the next 20 to 50 to 60 years,” Provost said.

Provost said the study was aimed at helping state and federal fishery managers determine which fisheries will remain viable and where to direct resources. She identified five species that will see big changes in 20 years, but when the models look 60 years ahead, half of the 34 species will experience significant changes.

As much as the study raised many concerns, Provost said there is room for some optimism. Species like Pacific bonito and hagfish showed low sensitivity to changing conditions. Provost said threatened species like red abalone might make a comeback if kelp beds are restored.

“We’re looking for solutions,” Provost said. “There’s a lot of hope in figuring out how to best adapt.”

The state’s fishing industry has struggled in recent years as many of its main fisheries have taken a hit. The commercial and recreational king salmon seasons have been closed an unprecedented two years in a row as the state’s drought caused a sharp population decline. Dungeness crab seasons have been limited as state officials seek to protect migrating whales.

“Seven or eight years ago I guess, we used to make a good living fishing,” said veteran fisherman John Mellor. “Now we’re just barely trying to survive.”

As a crab fisherman, Mellor traveled to Washington D.C. years ago to lobby Congress to devote more money toward studying ocean acidification and its effects on fisheries.

He hopes the new study will serve as a wakeup call to the challenges the state’s fishing industry faces now and in the future.

“If it helps us adapt to changing circumstances and it helps us keep making a living, then it’s a good thing," Mellor said.