Ecosystem-based fisheries management forestalls climate-driven collapse

Area of Science:

• Marine ecology
• Climate change science
• Fisheries management

Background:

• Climate change poses significant threats to global fisheries, impacting food and nutritional security.
• Fisheries in the eastern Bering Sea are particularly vulnerable to changing ocean conditions.
• Existing fisheries management strategies may not adequately address future climate impacts.

Purpose of the Study:

• To evaluate the effectiveness of Ecosystem-Based Fisheries Management (EBFM) compared to non-EBFM approaches in the eastern Bering Sea under climate change scenarios.
• To project the long-term impacts of climate change on key US fisheries, including pollock and Pacific cod.
• To identify potential tipping points in ocean temperature that could lead to rapid declines in fish biomass and catch.

Main Methods:

• Utilized management strategy evaluations (MSEs) for key US fisheries in the eastern Bering Sea.
• Modeled climate change impacts under different carbon emission scenarios (RCP 8.5 and RCP 4.5).
• Analyzed projected changes in species-specific fisheries, biomass, and catch in relation to modeled ocean temperatures.

Main Results:

• Ecosystem-Based Fisheries Management (EBFM) measures were found to forestall declines in fisheries compared to non-EBFM approaches in the near-term.
• Species-specific benefits of EBFM were observed, but these benefits markedly decrease after 2050.
• Under high-emission scenarios (RCP 8.5), pollock and Pacific cod fisheries face >70% and >35% collapse probability, respectively, by end-of-century.
• A modeled summer bottom temperature of 2.1-2.3°C was identified as a tipping point for rapid declines in gadid biomass and catch.
• Multiyear periods exceeding 2.1°C are projected to become common from ~2030 onward, particularly under RCP 8.5.

Conclusions:

• EBFM can ameliorate climate change impacts on fisheries in the near-term, offering a more resilient management approach.
• The long-term effectiveness of EBFM is constrained by the magnitude of anticipated climate change, highlighting the need for global carbon emission mitigation.
• Urgent action to reduce carbon emissions is critical to prevent severe, long-term declines in vital fisheries like pollock and Pacific cod.