An Ecosystem Approach to the Culture of Seaweed

Seaweeds are a significant component of current marine aquaculture production and will play an increasing role in global food security as the human population increases rapidly over the next 30 years. Seaweed farming is analogous to plant-based agriculture except that the crop is cultured in a marine environment. It also differs from agriculture in that seaweeds do not require tillable land, fertilization, or freshwater, which are resources that may ultimately constrain the expansion of agriculture. Seaweeds are converted into a variety of goods, such as food and nutritional supplements for humans and livestock, fertilizer, unique biochemicals, and biofuels. Wild and cultured seaweed also offer multiple ecosystem services, such as bioremediation for coastal pollution, localized control of ocean acidification, mitigation of climate change, and habitat for other marine organisms. Incorporation of seaweeds into marine aquaculture farms in the United States is, however, not without its challenges. Seaweed is an unconventional food which necessitates establishing product acceptability, creating a sustained market, and then balancing demand with a consistent supply for long term economic profitability. Seaweed farms also need to be developed in a manner that is compatible with wild capture fisheries, marine mammal migrations, and other users of the marine environment. A comprehensive understanding of the role that cultured seaweeds play in the marine ecosystem is necessary in order to determine not only the economic value of the goods produced but also the ecosystem services offered by marine farming activities. This will result in a better understanding of how an ecosystem approach to aquaculture incorporates the role and need for both the goods and services these macroalgae will provide.