A Case for Seaweed Aquaculture Inclusion in U.S. Nutrient Pollution Management

This report, published in Marine Policy, examines the potential role of seaweed aquaculture in addressing nutrient pollution in the United States. Nutrient pollution, particularly from nitrogen and phosphorus, has led to the expansion of hypoxic zones in coastal waters, with the Gulf of Mexico being one of the most affected areas. Traditional pollution control methods have proven costly and often insufficient, prompting researchers to explore alternative approaches. This report argues that integrating seaweed aquaculture into nutrient management strategies could help mitigate the effects of eutrophication while supporting economic opportunities in the aquaculture sector.

The study highlights how seaweed absorbs nitrogen and phosphorus from water, effectively removing these excess nutrients when harvested. Using the Gulf of Mexico as a case study, the researchers assess the feasibility of large-scale seaweed farming in reducing nutrient loads and alleviating hypoxic conditions. The analysis suggests that cultivating native seaweed species could contribute to meeting pollution reduction targets set by the Hypoxia Task Force, which aims for a 20% decrease in nitrogen and phosphorus pollution by 2025. The findings indicate that only a small fraction of the U.S. Exclusive Economic Zone (EEZ) in the Gulf would be needed for seaweed farming to have a meaningful impact on nutrient reduction.

The report also explores the economic viability of seaweed aquaculture by considering potential revenue streams. Emerging markets for seaweed-based products, including food, biofuels, bioplastics, and fertilizers, present opportunities for financial sustainability. Additionally, water quality trading programs could incentivize seaweed cultivation by allowing polluters to purchase nutrient removal credits. These programs, which operate within watershed management frameworks, could make seaweed aquaculture a cost-effective alternative to traditional nutrient mitigation strategies.

However, the implementation of seaweed aquaculture faces several challenges. The report discusses the importance of proper site selection to avoid conflicts with existing marine industries, the need for regulatory frameworks to support industry growth, and potential ecological risks, such as altering local nutrient cycles. While policy developments, such as the AQUAA Act and NOAA's Aquaculture Opportunity Areas, indicate growing support for seaweed aquaculture, social acceptance, and industry regulations remain critical factors for success.

In conclusion, the report presents seaweed aquaculture as a viable and scalable solution for nutrient pollution management. It underscores the need for continued research, policy alignment, and market development to fully realize its potential. The findings suggest that if implemented strategically, seaweed farming could become an effective tool in reducing nutrient pollution while contributing to sustainable aquaculture practices in the U.S.