Kelp as an Up-and-Coming Product
Sugar kelp is a new and popular product in the U.S. aquaculture industry. Not only is kelp a nutritious and sustainable food option, but it offers restaurants and bars the chance to make innovative drinks and dishes featuring locally grown kelp. Farmed kelp is grown in the winter, so many kelp growers are lobstermen who grow the product in the off-season from lobstering, but there are a few full-time sea farmers who focus on the crop. Ken Sparta of Spartan Sea Farm in Freeport is one of those people. While Spartan Sea Farms also grows oysters during the summer months, their boat is specially rigged for harvesting and transporting kelp.
Kelp Harvesting, Explained
Most farmed kelp begins its life in a lab. Wild adult kelp are spawned in a lab, and the spores settle onto spools of twine. At the beginning of the growing season in the fall, the twine is wrapped around larger rope lines and stretched between moorings to grow. While kelp can grow all year in the Maine waters, the growing season is typically in the winter because other growth in the ocean slows, limiting biofouling and allowing growers to harvest only the kelp that they want. Once the kelp is fully grown in the spring, it is cut from the lines and pulled into a boat, where it is brought to shore for processing.
The Boat and Winch System for Harvesting Kelp
A line of fully grown kelp is really heavy. A single 20-foot section of kelp line might weigh as much as a few hundred pounds. In order to avoid putting large stresses on their boat, many kelp farmers lift only a small section of line at a time. In order to streamline the harvesting process, Spartan Sea Farm uses a specially designed boat that is able to lift longer stretches of kelp longline out of the water and up to shoulder height for easier harvesting.
The port side of the Spartan Sea Farms boat houses a unique dual-winch system consisting of one winch at the stern of the boat and another near the bow. To harvest a section of line, one piece of the line is pulled up to the top of the stern winch by hand. The other winch is connected to the line and hauled up to shoulder height with the winch. The result is a about 20-foot stretch of kelp conveniently suspended just above the gunwale.
To harvest the kelp, the Spartan Sea Farms team places crates on the boat gunwale and cuts the kelp directly into the crates. This method works especially well for separating the kelp blade from the stipe (see the diagram below). Once the kelp is loaded into bags for transporting back to shore, the harvest weighs thousands of pounds. The Spartan Sea Farms boat was designed to hold 8,000 pounds of weight, a massive amount for a 23-foot boat. Tall gunwales and a sturdy design mean less trips to offload product are required during harvesting season.
Kelp Innovations Are Worth the Effort
One of the reasons kelp is becoming more popular is the low barrier to entry in the kelp-growing field. For fishermen who already have a large boat, there isn’t much other specialized gear required. Although it’s not necessary to have a specialized harvesting system like Spartan Sea Farms, investing some effort into a better kelp harvesting system has its benefits. The dual-winch harvesting system saves growers’ backs from heavy lifting, reduces the time to get the product to processing, and makes the overall harvesting process more streamlined. Although it may not be necessary to grow kelp, a harvesting system like this might be a good investment for many growers who are already in the field today or thinking of entering it soon.
Innovations articles highlight creative devices or methods on aquaculture farms. They are informed by farm visits and interviews with experienced growers. See our About page for more information.