Kelp mariculture in Alaska
By SUE KELLER
April 22, 2018
That message was supported this month by presentations at Ocean Tuesday, a weekly forum for promoting Alaska’s maritime economy. Presenting were Alaska Sea Grant–funded graduate student Annie Thomson and Tamsen Peeples of Blue Evolution, a California-based company. They talked about their work on kelp mariculture in Alaska. Alaska Sea Grant and Blue Evolution are collaborating on a federal grant to address biological traits that limit seaweed farming development in Alaska.
Blue Evolution is the first company to culture and process kelp in Alaska, focused on ribbon kelp and sugar kelp. In 2017 Blue Evolution harvested 10,000 pounds of wet kelp grown by two independent farmers on Near Island and Larsen Bay.
Mike Stekoll, University of Alaska Southeast professor of chemistry and biochemistry, began studying seaweed cultivation with Peeples in 2015 with funding from Blue Evolution. In 2016 Peeples built a commercial kelp hatchery at UAS, placing Plexiglas tanks on shelves with string-wrapped PVC pipes inside the tanks. Growing on the string are young kelp plants called sporophytes.
In the fall season Peeples collects kelp with fertile fronds and brings them to the lab. In sterilized seawater the spores are released to the string-wrapped pipes, where the plants develop through the life cycle to the sporophyte stage. After incubation they are outplanted to the coastal farms in the fall, where they grow to a harvestable size of 9-12 feet by April or later.
Worldwide there is a big demand for seaweed for food, health and beauty products, animal feed and biofuels. Blue Evolution sells a line of pasta products with seaweed and provides seaweed to other companies.
“There are many great reasons for pursuing seaweed culture in Alaska,” said Peeples. “There is a huge space for it, Alaska has diverse species of seaweed and a fleet of vessels is available for harvest and transport.”
Annie Thomson talked about the progress she has made on her master’s research on sugar kelp biology at the University of Alaska Fairbanks College of Fisheries and Ocean Sciences, advised by Stekoll. She is attempting to answer the questions, when are sporophytes fertile, and can we control the time from seeding strings to the ready-for-outplant stage?
At three sites near Juneau with the ideal sandy habitat, Thomson saw sugar kelp acting as an annual at some beaches and as a perennial at others. In Juneau the kelp starts growing in March and by May some produce spores. The timing of sugar kelp fertility differs between Juneau and Kodiak, which Thomson and Peeples will study this year.
Thomson’s lab studies showed that withholding iron is effective in delaying the life cycle and thus the outplant time. She will also look at temperature and the amount of light to slow development. “Dr. Stekoll calls this ‘cold banking.’ You can outplant it when you want to,” said Thomson.
In Kodiak Peeples has set up a large commercial seaweed hatchery in cooperation with the National Oceanic and Atmospheric Administration lab. She is working with the lab to find suitable seaweed mariculture sites, including testing water pH and nitrogen content. Blue Evolution leases space in the UAF Kodiak Seafood and Marine Science Center to process the harvested seaweed.
One of the biggest challenges to kelp mariculture in Alaska, said Peeples, is the permitting process. “Three agencies are involved, at the state and federal level. It can take two to five years to get a permit now. But the agencies are willing to cooperate,” she said.
A new sugar kelp project is starting this year with funding from the US Department of Energy, to develop culture efficiencies that would lead to large scale production for energy. Stekoll, who leads the project, is working with universities, nonprofits and private companies in Alaska and on the East Coast.
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