Ocean temperatures have hit record highs this year, growing so hot in some places that taking a dip in the sea feels like stepping into a hot tub. For kelp farmers, who grow an underwater crop with a life cycle highly dependent on temperature, that spells trouble for their harvests – and their nascent industry’s future. “Over the last 30 or 40 years, we’ve seen a pretty big decline in the kelp populations around Long Island. In large part, that’s due to climate change and water temperatures increasing,” said Michael Doall, a former oyster farmer and marine scientist at Stony Brook University’s School of Marine & Atmospheric Sciences.

Doall is just one of many scientists working on solutions that will help make the burgeoning industry more climate resilient. Their research subject, kelp, has been billed as the future of food: the sea vegetable doesn’t require land, fresh water or fertilizer to grow, allowing it to sidestep some of the harms that accompany traditional resource-intensive terrestrial agriculture.

It grows up to 2ft per day, making it efficient at pulling climate-warming carbon and ecosystem-disrupting nitrogen from land-based fertilizer runoff out of the water. And it’s a delicious ingredient that can be used to add a rich umami flavor to everything from sushi and burgers to pickles and salads.

“It’s often called the Swiss army knife of the sea, or the tofu of the sea. It can be turned into so many different things,” said Scott Lindell, a research specialist at Woods Hole Oceanographic Institution in Massachusetts. Kelp has been farmed as food in Asia for millennia and harvested by tribes like the Shinnecock and used for everything from food and medicine to housing insulation in what’s now known as Long Island, New York, since long before settlers arrived. But kelp farming as a commercial endeavor – in which kelp is grown on tensioned ropes secured by anchors and buoys a few feet below the water’s surface that are pulled up for harvest – began in North America just a few decades ago.

It is increasingly being sold as a valuable food product in North America, as well as a useful ingredient in bioplastics, cosmetics and even renewable fuels….

https://www.theguardian.com/environment/2023/aug/12/kelp-farming-ocean-temperatures-climate-crisis