Promise and Challenges of Open-Ocean Aquaculture

With demand for seafood tripling by 2025 according to the Department of Commerce, and fishing stock exploited or overly exploited in some species, an eye is turning toward open-ocean aquaculture. Open-ocean aquaculture involves the rearing of marine organisms in exposed areas beyond coastal influence. Due to open-ocean currents, winds and wave action, excess feed and waste can be naturally removed maintaining water quality. And offshore farming does not conflict with recreational use. Some researchers are concerned with the ecological and environmental impact including the impacts on existing wild populations. Natural stocks could be threatened by disease outbreaks that are commonly associated with high-density fish farms.

New technology is making open-ocean aquaculture more efficient, but a number of challenges remain including permitting processes, the development of federal regulatory systems, and identifying key species best suited for open-ocean aquaculture.  Both scientists and conservationists see possible threats and benefits of domesticated operations. Fish species such as Bluefin Tuna, Cod and Halibut have a large market value and are poised to play a large role in the future of the industry. Extensive research has been done with other carnivorous species such as Salmon. Those benefits have been challenged. The main species farmed in the marine environment are Atlantic salmon, shrimp, oysters, and hard clams; together they account for about one-quarter of total U.S. aquaculture production. Freshwater species, such as catfish, account for the majority of U.S. aquaculture output.

Most scientists and conservationists believe there is great potential, but with that comes great risk. A comprehensive structure would be needed, a framework that should integrate federal and state laws integrating regional ocean planning with management efforts. As part of a National Marine Aquaculture Initiative, the National Sea Grant College Program has initiated research throughout the United States on open ocean aquaculture. Many species are currently being studied, including halibut, haddock, and cod at the University of New Hampshire; black sea bass at the University of South Carolina; mutton snapper at Universities of Miami and North Carolina; cobia at the Universities of Virginia, South Carolina, Mississippi, and Texas; yellowtail snapper at the University of Texas; corvina at the University of California; and bay scallops at the National Oceanic and Atmospheric Administration (NOAA) Fisheries Milford Laboratory in Milford, CT, the University of South Florida. Other research initiatives include hatchery culture technologies; designs for automated feeders; culture of new species; identification and control of diseases; development of cages and husbandry technology for rough water environments; identification of alternative food sources; understanding of nutrition requirements; definition of carrying capacity of offshore waters; and development of environmental monitoring technology.