In recent years, seaweeds have been notorious for washing up and fouling beaches on Long Island. Now, a collaborative team of scientists and marine farmers have demonstrated that the seaweed, sugar kelp, can be cultivated in the shallow estuaries of Long Island, a breakthrough that may unlock a wealth of economic and environmental opportunities for coastal communities.
A new wave of small owner-operated oyster farms is revolutionizing NY’s marine aquaculture industry, but a lack of crop diversification leaves these farms vulnerable to crop failures and/or downturns in the market for oysters. Sugar kelp (Saccharina latissma) is an emerging specialty crop in the northeast U.S. with enormous potential, but has yet to be grown on Long Island oyster farms until now. This winter, a collaborative team including marine scientists at Stony Brook University (SBU), 3D ocean farming innovators at the non-profit organization GreenWave, local seafood industry pioneers from Dock to Dish and Haskell Seafood, and several Long Island oyster farmers, have teamed up on a grant to SBU from the New York Farm Viability Institute to bring this crop to Long Island. The team deployed “commercial-style” lines of kelp on oyster farms in three estuaries around Long Island, including Great Gun Oyster Farm in Moriches Bay, East End Oysters in Long Island Sound, and a Town of Islip aquaculture lease in Great South Bay.
The results have been astonishing. In just three months, kelp blades have grown to over four feet at one of the sites, outpacing every known kelp farm in NY and CT.
“The implications of our study for Long Island oyster farmers are very exciting”, says project co-leader Michael Doall, a marine restoration and aquaculture specialist at Stony Brook University’s School of Marine and Atmospheric Sciences (SoMAS). “Kelp farming can provide Long Island oyster farmers with a means to diversify crops, create additive revenue streams, and further contribute to the sustainability and health of Long Island’s estuaries through restorative aquaculture.”
What makes the study particularly interesting is the site where kelp has grown the best. Previously, the conventional wisdom among aquaculturists was that kelp farming needed to be done in deep water (i.e. > 20 feet) so that the kelp blades do not touch the bottom. However, many of the existing oyster farms on Long Island are located in shallow water estuaries, particularly on Long Island’s south shore. To the research team’s surprise, kelp has grown the best at the shallowest site in Moriches Bay, where low-tide water depths ranged down to just a foot. Despite this, the kelp has grown from seed to over 4-feet in length with the kelp blades clean and intact, free of fouling, tears, or damage.
“It’s astonishing to see how fast this beautiful plant grows,” says Paul McCormick, owner of Great Gun Oyster Farm in Moriches Bay and one of the study’s collaborating farmers. “It’s a low-maintenance crop that grows in the dead of winter, so it fits in perfectly with the cycle of my farm, offering additional income during a tough time of the year; I’m definitely interested in incorporating kelp on the farm.”
And beyond its remarkable nutritional profile, kelp holds the promise to improve water quality across Long Island waters. While some aquaculture practices such as fish farms are known to pollute water ways, the combined farming of kelp and oysters is recognized as “regenerative and restorative” aquaculture, as the organisms collectively sequester nitrogen and carbon from estuaries. Furthermore, the kelp alone produces oxygen, combats ocean acidification by removing carbon dioxide, and may even combat harmful algal blooms.
“Long Island is in a battle to improve water quality and restore its bays, harbors and estuaries,” said Chris Gobler, Professor of Marine Science at Stony Brook University and primary investigator of the study. “As kelp grows, it removes the things we don’t want in our waters, namely nitrogen and carbon dioxide, and provides oxygen that all marine life need to thrive. We think the aquaculture of seaweeds represents another important tool for improving water quality on Long Island.”
In addition to occurring naturally in NY waters, sugar kelp is an ideal crop for integrating into oyster farms. First, sugar kelp is a cold temperature crop whose growing season is opposite that of oysters. This allows farmers to redirect labor and resources from oysters in the warm months to kelp in the cold months, thereby limiting the capital investments required to start this new crop, and helping farmers retain good employees and bolster local economies by turning seasonal farm hands into year-round employees. Secondly, kelp can be vertically integrated with bivalves, creating a three-dimensional polyculture farming system that does not require one crop to replace the other. Such 3D ocean farming techniques produce multiple revenue streams that are additive on a per acre basis, allowing for increased profitability as well as diversification. This 3D ocean farming model is pioneered by GreenWave, a non-profit working to catalyze farm replication and market innovation in New England and beyond.
“Being able to grow sugar kelp in shallow water is only the first part of the story,” emphasizes Michael Doall. “Sugar kelp will only be a viable crop on Long Island if there’s a market for it and if it can be profitable. In the next phase of our study, we will be engaging local chefs, restauranteurs, and other food industry professionals to evaluate market acceptance and demand for Long Island farmed kelp. Our early results indicate strong interest from the foodie community.”
“If sugar kelp can be profitably farmed in shallow water estuaries,” Gobler concluded, “it would be a true a win-win proposition for Long Island, benefitting both local economies and the marine environment.”