Shellfish Aquaculture Complements Nutrient Reduction in Mitigating Climate-Exacerbated Coastal Hypoxia

Area of Science:

• Marine Biology
• Oceanography
• Environmental Science

Background:

• Coastal hypoxia, a severe threat to marine ecosystems, is driven by nutrient enrichment and global warming.
• Reducing land-derived nutrients is a primary strategy, but climate change impacts and rising costs pose challenges.

Purpose of the Study:

• To assess the effectiveness of land-based and alternative nutrient mitigation strategies under future climate change scenarios.
• To evaluate these strategies in a representative estuary-shelf system for near-term and long-term projections.

Main Methods:

• Combined field measurements with a coast-resolved physical-biogeochemical model.
• Assessed mitigation strategies under projected climate change scenarios (2016-2045 and 2071-2100).

Main Results:

• Stringent land-based nutrient reduction alone is insufficient to prevent deoxygenation under climate change.
• Climate warming and increased river discharge enhance stratification, limiting oxygen replenishment.
• Oyster aquaculture emerges as an effective complementary strategy for nutrient removal and hypoxia mitigation.

Conclusions:

• Climate change impacts, particularly stratification, undermine the sole reliance on land-based nutrient reduction for coastal hypoxia.
• Oyster aquaculture presents a viable, incentivizing supplementary solution aligned with global aquaculture trends.
• Integrated strategies are crucial for managing coastal nutrients and mitigating hypoxia globally.