A sample of sugar kelp is harvested for testing in...

A sample of sugar kelp is harvested for testing in East Moriches in April. Credit: Randee Daddona

A battle is underway over the future of farming off our coasts as industry groups push to authorize large-scale aquaculture operations in state and federal waters.

But not all aquaculture is created equal. There are stark differences between the kelp farming sector now authorized in New York State waters, and industrial finfish aquaculture, which should remain banned.

The "Kelp Bill" passed by the State Legislature this summer has been signed by Gov. Kathy Hochul. It will let specific types of seaweed be commercially grown and harvested in Peconic and Gardiners bays, allowing ocean farmers to begin producing food, fuel and fertilizer derived from locally grown kelp and other macroalgaes. The legislation was supported by environmental organizations, community groups, academic institutions, and shellfish farmers — with only a few yacht clubs in opposition.

But the bill must not be seen as creating an opening for other forms of aquaculture. Industry groups are pressuring the Biden administration to license offshore, open ocean fish farms. One company has spent six years seeking permits to farm finfish in federal waters off New York, and plans to place 18 submersible cages in federal waters eight miles off the coast of Southampton.

The problems with finfish aquaculture have been scientifically demonstrated. For one, finfish farming puts additional pressure on wild fish populations: Fish feed is made up mainly of other small fish caught from the ocean, and it takes an estimated 6 kilograms of captured fish to make 1.15 kg of dry feed. These small fish could be eaten directly, rather than turned into fish food. Farming carnivores is a net loss of animal protein.

Fish farms create a lot of pollution in the form of nitrogen and phosphorus, which can lead to ocean dead zones. Open ocean farms also can be hot spots for sea lice, and require treating farmed fish with large amounts of antibiotics. Farmed fish may escape, spreading diseases to wild fish.

Finfish farming has long been banned in Alaska. In 2018, Washington State banned nonnative fish farms. British Columbia and Denmark are phasing out the industry as well.

The best aquaculture operations should not require fish caught from the wild to feed farmed animals, should not require conversion of habitat or contribute to pollution, and the species under cultivation should be native to the region and those least likely to experience pain and suffering in captivity.

The ideal aquatic species to farm are macroalgaes, like seaweeds and kelps, as well as bivalves, such as oysters, mussels, and clams. These species do not need to be fed, do not require large amounts of antibiotics, and do not create extra pollution — in fact, bivalves can help clean waterways, and kelp sequesters nitrogen and serves as a carbon sink. Of course, even kelp and bivalve farming needs to be limited in size, zoned to protect essential sea grass and other vulnerable habitats, and managed in ways that reduce use of plastics and pesticides.

We understand the desire to address the U.S. seafood trade deficit in which we import more seafood than we produce. Sustainable aquaculture of bivalves and macroalgaes must be a key component in that strategy. We should also consider reducing consumption of imported wild seafood and overexploited fish from foreign waters.

We need resilient, healthy food systems, and industries with a sustainable future. New York State legislators should carefully license only kelp and shellfish farms and continue to prohibit finfish farming in all forms, while pushing federal legislators to do the same.

This guest essay reflects the views of Jennifer Jacquet, an associate professor at New York University, and Sean Barrett, co-founder of Dock to Dish and the Montauk Seaweed Supply Company.