Ecological and economic impacts of ocean deoxygenation on Pacific halibut fisheries: A multidisciplinary assessment of projected losses

The ocean has lost oxygen content since the last century, accelerated by climate-induced warming, acidification, and anthropogenic nutrient loading. This deoxygenation alters marine ecosystems, threatening fishery-dependent human well-being. Marine fishes are highly sensitive to dissolved oxygen levels, which influence their mortality, growth, and abundance. Estimating the resulting economic impacts on fisheries is hampered by uncertain links between biogeochemical pathways and socio-economic outcomes. Thus, we applied a multidisciplinary model integrating ecological (metabolic rate index), biological (stock biomass dynamics), and economic (MSY-based rent) components to assess deoxygenation impacts (2020−2100) on the British Columbia Pacific halibut fishery. We find that under up to a 40% reduction in dissolved oxygen and a 30% temperature increase by 2100 (relative to 1994), Pacific halibut biomass could decrease by 66% to 89%. This could translate into an estimated cumulative economic loss of $100 million by 2100. Notably, the fishery may remain biologically resilient until 2050, followed by severe declines as deoxygenation accelerates. Supply chain ripple effects across secondary and tertiary industries could cause an additional $197 million loss by 2100. Therefore, it is crucial for the International Pacific Halibut Commission (IPHC) to incorporate adaptation and mitigation strategies to counteract ongoing deoxygenation and warming.