Tuesday July 7, 2026
Global Seafood Alliance —
Over the past century, the ocean has been losing oxygen and the pace has picked up because of climate change-driven warming, ocean acidification and human activities like farming and wastewater that dump extra nutrients into the sea. This deoxygenation is changing marine ecosystems and putting real pressure on communities that rely on fishing for their income and way of life.
Fish are very sensitive to oxygen levels in the water. When oxygen drops, it can increase death rates, slow growth and reduce how many fish are available overall. However, turning these biological changes into clear economic numbers is difficult because the connections between ocean chemistry and actual financial impacts are still uncertain.
A study by Hongsik Kim and colleagues at the University of British Columbia in Canada focused specifically on the Pacific halibut (Hippoglossus stenolepis) fishery in British Columbia and looked ahead from 2020 to 2100. It involved the construction of a combined model that links three factors: how fish metabolism responds to lower oxygen and higher temperatures, how halibut populations (biomass) are likely to change over time, and the economic value of the fishery based on sustainable harvest levels.