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Knowledge Exchange Seaweed on Tour: What We Learned in Alaska and Maine
- Scotland Seaweed
- Jul 29, 2025
- 7 min read
Updated: Jul 30, 2025
By Rhianna Rees with input from Rob Grisenthwaite, Leigh Eisler, Iain Matheson, and Jemima Cooper
In May of 2024, eight delegates from Alaska and New England, funded by SeaGrant, came to visit Scotland, looking to learn about our seaweed sector, processing solutions, scale of production, and ultimately share experiences. The visit was a tremendous success, with strong partnerships and bonds created to support both countries across the pond. And, of course, an open invite for a return visit.
With financial assistance from The Fishmonger's Company, the SSIA, and on the ground assisstance from SeaGrant and MAIC we were finally able to make it happen in June 2025. Delegates were selected from the SSIA membership, prioritising those who had hosted the US delegates within the previous year. We were also able to gather a contingent with expertise across the entire value chain, from nursery through to farming, processing and policy.
First Stop: Kodiak, The Emerald Isle
Kodiak is an incredibly independent island within an enormous state, dubbed the 'emerald isle' for its lush greenery in the summer. The island is 98% powered by hydroelectricity (~70-80%) and wind (~10-20%), making it almost entirely self-sufficient for energy.
We were told the islanders unofficial motto was: “We do what we do and don’t like to be told what to do.” focusing on a freedom to test things out, make adjustments/improvements where possible, and, of course, innovate.
We toured both Nick Mangini’s and Alf's farms, which grew sugar kelp (Saccharina latissima), bull kelp (Nereocystis luetkeana), three ribbed kelp (Cymathaere triplicate), dragon kelp (Eularia fistulosa), ribbon kelp (Alaria marginata), and giant kelp (Macrocystis pyrifera).
While the temperature range is similar to Scotland during the growing season (approximately 4°C–14°C), the size of the biomass still caught us by surprise. We were told that a nearby shelf circulates nutrient-rich water from the deep ocean directly up to the farms, driving extended grow-out periods and producing colossal macroalgal plants.
The farms also opted for catenary arrays which allowed for much tighter spacing through tensioning (1m apart, but the farm design can even allow for up to 10cm) making their sites much more productive in a smaller area. In Scotland, the preferred site design is a grid or long-line system, meaning spacing can only reduce to a maximum 2m apart.
Although, we did find out that licencing costs run a lot higher in Kodiak. Alf's farm at 100 acres (40 Ha) cost him $12,000 a year to licence, a price that would likely put many farmers out of business in Scotland.
There is a noted freedom in the kelp farmers ability to adapt and change their boats according to their needs, which is in strict contrast to the British MCA coding system. As a result, they are able to make leaps and bounds in developing mechanisms to improve harvesting year on year - something which could take years if not decades to do in Scotland. Nick's boat had a gap in the gunnel where they had their seaweed bag chute. The grow line comes in up over the gantry, and they cut into this funnel, where a bag attached to the outside of the boat collects it. Once filled, it is left to float in the ocean keeping the harvested kelp alive, and is then towed to a tender where it can be lifted out of the water using a hi-ab crane. No modification paperwork, just a simple, practical design that is modular.
Processing Power (and Pain)
We then visited the University of Alaska's Kodiak Seafood and Marine Science Centre which hosts a number of processing trials. They’ve got freeze dryers, blast freezers, blanchers, and mills ready to test on species. Farmers can test the kit for free. Scaling still has its challenges, though. The equipment itself has a habit of clogging, heads on choppers needed regular changing, and they had bought a salad spinner that couldn’t handle salt water. (Their advice: “Don’t buy an Electrolux for kelp.”)
We also got the chance to look in on Blue Evolution, Alaska’s only dedicated kelp processor. They blanch, chop, and ferment for animal feed with lactobacillus. Over in Cordova, Noble Ocean Farms are testing rotary dryers, acid sprays, and trying to build a co-op to share gear each year. Most farmers across Alaska seem to be selling to Cascadia and margins tend to be quite thin.
NOAA Labs
At the National Oceanic and Atmospheric Administration (NOAA) labs, we were able to learn more about their extensive crab research, including studies on Ocean Acidification (OA) and climate resilience. They also had various seaweed nursery experiments going on, looking at treatments over time, as well as a modular series of tanks that could be brought into a class for STEM outreach to children. The biggest questions they’re researching? Quantifying ecosystem services at kelp farms, from fish habitat to benthic impacts, something we're both very interested to see develop.
Next Stop: Maine – Lobsters, Licences, and Limited Space
If Alaska has space but struggles with cost, Maine has the opposite problem. Here, the bottleneck is licensing. If you're looking for a functional multi-year lease there’s a five-year wait. Most farmers stick to LPAs (Limited Purpose Aquaculture sites), which are tiny (400 ft2) and need to be renewed each year.
We first met with Atlantic Sea Farms whose focus is on a vertically integrated model: they give lobster fishers seeded spools for free to grow themselves, buy back the harvest, and turn it into value-added products like kelp kimchi to whole foods retailers. Sounds like the perfect set up, but they are still holding frozen stock from years ago. Demand is growing, but slowly. Just like in Scotland, the biggest barrier isn’t necessarily growing the seaweed, it’s selling it.
Gear of the Future (Made of Seaweed)
One highlight? Viable Gear, a start-up making biodegradable fishing gear from seaweed cellulose working with Scotland's spin-out Mercel. They’ve even prototyped seed twine that biodegrades in seawater. Right now, it lasts about a month, which isn’t enough for kelp to mature, but they're doing trials with Nordic Seafarm in Sweden, and we hope to see positive results soon.
Maine’s Innovation Hubs
At the Maine Aquaculture Innovation Centre, we saw an incredibly high-tech nursery with conical bioreactors, bulk algae cultivation, and the Industrial Plankton system: 12 reactors, smart controls, and a price tag of around £120,000. Costly, yes, but it’s been running healthy cultures for over a year. It’s got a built-in “blender” to break down biomass, and lighting and media you can adjust/drain without opening the reactor. The dream is to use it to optimise culture density from micrograms to kilograms.
They also boasted The Korean Unicorn, a twine deployment machine that feeds rope and twine simultaneously. Instead of wrapping twine in the lay of the rope, it uses a bronze reel to bind them both along the in a single motion to reduce twine wastage and ensure the twine stays flush during the grow-out period.
We happened to find ourselves in Maine at the same time as the Maine Oyster Festival, a fantastic celebration of all the oyster producers in the area organised by Ken Sparta, who runs Spartan Farms and a working waterfront co-op. Spartan Farms also had a tidy little nursery set up in a shipping container on the dock with filters, UV, IBCs, and batch seawater cycling.
Processing Capacity
Maine also gave us a peek into large-scale processing. Source / Ocean’s Balance runs a huge custom-built dehydrator, which can dry 450 kg of kelp an hour (on a good day). Even then, consistency and reducing costs are their biggest challenges, especially when they require in-person oversight for seemingly small tasks, such as watching a conveyor belt. Source produce their own product range of equine, dog, cat and human feeds which have been increasing in popularity.
Ocean Organics, a biostimulant company who have been operating for 30 years, produce high-end turf products (surfactants), took us through what appeared to be a never-ending warehouse of dryers, millers, choppers, fermenters, pelletisers and more.
Meanwhile, at Maine Coast Sea Vegetables we talked about the power of community, where they’ve been employee-owned since 2017, support 30 harvesters, and still sun-dry some of their seaweed to an organic standard. Their biggest challenge appears to be in licensing and harvesting areas. Individuals in Maine hold a wild harvesting licence which is not specific to any one area (unlike in Scotland), so harvesters could potentially harvest on top of one another. Shep has been working hard to coordinate these harvesters and allow for the sustainable regrowth of material each year.
What Scotland Can Learn
Processing before production. Both states proved the point: growing kelp is the easy part. Scaling processing and product development? That’s the key challenge.
Innovation loves freedom. Looser vessel rules in Alaska let farmers adapt fast. We need a serious chat with the MCA if we want to keep up.
Collaboration works. From gear-sharing co-ops in Cordova to employee-owned businesses in Maine, shared resources make sense in an emerging industry.
Markets matter most. Until demand grows, we as a sector are fighting an uphill battle. It's great to see the seaweed sector flourishing everywhere, but we need follow through on the hype.
The trip gave us incredible insight into what the seaweed sector is like in the US, in two very different parts of the same country. In Alaska, we saw that space was less of an issue, as appeared to be regulatory oversight, but the distance from the mainland, as well as acess to the lower 48 (if I'm saying that right?) meant that cost was always a big consideration.
In Maine, innovation was much more prominent, with plenty of shops around Portland selling seaweed products, and companies constantly interating to solve challenges. There was also a buzz of excitement and genuine interest from oyster farmers to get engaged with the seaweed sector. It feels like both states are primed to make the most of a thriving seaweed industry, if the market has the capacity to keep up.
Massive thanks to our hosts, especially SeaGrant Alaska and MAIC for hosting us, driving us, feeding us, and making us feel so welcome. We look forward to the continued collaboration across our two countries and an opportunity to solve the collective problems we all face, together.
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