Scientists Advance Tools to Support Kelp Farming Industry

Maine is the epicenter for the rapidly-growing commercial seaweed industry, producing a larger supply of farmed seaweed than any other state.

Versatile and nutritious, sugar kelp is the favorite crop of the local industry. It’s grown on long, parallel lines of ropes, suspended into the ocean, on which early-stage kelp spores mature into harvestable adults. But, unlike with most row crops, kelp farmers in the U.S. still largely rely on spores from the wild to seed their lines, leaving them vulnerable to any shocks to wild seaweeds.

A team of scientists from Bigelow Laboratory are working to minimize that vulnerability by developing methods to cryopreserve different stages of sugar kelp, which could provide farmers with readily available cultivated spores. That kind of seed bank would also enable nurseries to preserve the extra spores they collect from the wild each year and help scientists better understand the biodiversity of Maine’s seaweeds.

“Farmed seaweed in the US still hasn’t been truly domesticated as it has in other countries, which means our farmers are extraordinarily vulnerable having to locate, collect, and work with wild broodstock every year,” said Senior Research Scientist Nichole Price, the director of the Center for Seafood Solutions and one of the project’s researchers. “Creating, in essence, a seed bank, would give them insurance against failures in the wild population or storm damage to farms.”

In some places, like Europe and Japan, farmers have already moved away from wild seeding, instead relying on live cultures of gametophytes, an intermediate stage in the kelp life cycle. While that approach offers stability for the industry, it’s labor intensive. Cryopreservation, in contrast, could offer that stability with potentially significant cost savings, especially if there was a centralized hub offering the service to farmers and nurseries across the region.

Senior Research Scientist Nicole Poulton, the project’s lead, said the idea was inspired by the National Center for Marine Algae and Microbiota, which has housed one of the world’s most genetically diverse collections of marine algae at Bigelow laboratory since the 1980s.

“At NCMA, we have much of our microalgae cryopreserved, so the idea was to try something similar, like a seed bank, for the seaweed industry,” Poulton said. “This could be a method or service providing locally produced, cryopreserved seed, ready to reconstitute at a moment’s notice.”

Using funding from the Sash A. and Mary M. Spencer Entrepreneurial Fund, the team began testing several methods to keep the cells alive through the cryopreservation process so the thawed spores would have the best chance of reseeding the next generation of the crop. With positive preliminary results from the Spencer grants, the team successfully applied for funding in 2020 from the USDA Northeast Sustainable Agriculture Research and Education program.

So far, they’ve had success thawing spores and getting them to mature to the next life stage, even after being frozen for a year or more. While most of the work has focused on preserving spores, one of the earliest and simplest life stages of kelp, they’ve also begun exploring the possibilities of cryopreserving other seaweed life stages. It’s a larger challenge given the increase in biological complexity, but it would be invaluable for farmers who would save weeks of culturing time.

The researchers are also developing new approaches for setting seed at farms in order to help increase the viability of thawed samples. This work is currently being trialed off Ocean Point Marina in Boothbay Harbor, at a state-permitted lease site, as an experiment to see what grows in the coming months in partnership with the Boothbay Sea and Science Center.

Throughout the project, Atlantic Sea Farms has been an invaluable partner. As the nation’s largest seaweed cultivation company, ASF distributes wild seed to more farms across the region than any other nursery. They’ve provided space for experiments and helped the scientists extract the spores from kelp tissue collected from across ASF’s farms.

“From the industry perspective, cryopreservation provides an opportunity to retain a portion of microscopic spores and draw from them months, even years, later as needed for whatever reason,” said Thew Suskiewicz, director of seaweed science at Atlantic Sea Farms. “Having this tool will be like having a living library, and it’s been great to work alongside the Bigelow Laboratory team to explore the possibilities.”

Photo Captions:

Photo 1: Thew Suskiewicz, director of seaweed science at Atlantic Sea Farms, observes the process of sporulation, when mature kelp plants release their spores, at ASF’s facility (Credit: Laura Lubelczyk).

Photo 2: Brittney Honisch, senior research associate at Bigelow Laboratory, preps a line seeded with kelp spores before it’s deployed in the water (Credit: Laura Lubelczyk).