Maine Seafood Guide – Seaweed
Health Benefits & Risks
Buying & Preparing
Sea vegetable (seaweed or macroalgae)
Wild and cultured.
There are over 250 species of sea vegetable (marine macroalgae or seaweed) in the Gulf of Maine. While most are technically edible, only 11 are commercially harvested; these include reddish-purple dulse (Palmaria palmata); long, golden-brown kelp (Saccharina latissima, Laminaria digitata, and Alaria esculenta); thin green sea lettuce (Ulva lactuca); and laver or nori (Porphyra umbilicalis). Rockweed (Ascophyllum nodosum) is the dominant species in the commercial harvest but is used as an ingredient in supplements and other products.
View a gallery of some of the important seaweed species in Maine.
Depends on individual species. Cultured sugar kelps are grown in the winter months and harvested in spring. Other kelps peak in spring to early summer.
Depends on individual species and varies locally. Rockweed beds are managed for optimal growth; plants regrow in 2-4 years with proper harvesting methods.
Maine Department of Marine Resources.
Sea vegetable companies harvest mostly wild plants by hand, at low tide, between April and October. Sea farmers grow seaweed in Maine coastal waters on “seeded lines” —rope with juvenile plants attached—and harvest these by hand. Rockweed, which is not consumed unprocessed but may be an ingredient in food or nutritional supplements, is harvested (cut) by hand with rakes and by mechanical harvesters.
Harvest for personal consumption is permitted; DMR has designated seaweed harvesting a fishery, and citizens can harvest up to 50 pounds per day for personal use under Maine law. Seaweeds should be harvested by trimming the blades from the ends of the plants, leaving the holdfast attached. Use caution in the intertidal zone: rocks are slippery and waves can be unpredictable. It’s also best to avoid harvesting near sewage outfalls, storm drains, or other potential pollution sources.
►Health Benefits & Risks
Seaweed contains essential minerals and vitamins, as well as fiber, protein, and iodine. Avoid collecting seaweed growing near sewage treatment plants and other wastewater outfalls.
►Buying & Preparing
At the retail level, sea vegetables harvested or grown in Maine will be labeled appropriately. If collecting yourself, take along a field guide such as Life between the Tides.
►Companies, Brands, and Labels
- Maine Coast Sea Vegetables
- Ocean Approved
- Maine Seaweed
- Ironbound Island
- Atlantic Holdfast
- Maine Fresh Sea Farms
- Vitamin Sea
Maine seaweeds can also be found in Seabelt Ale from Marshall Wharf Brewing Company, in bagels from Southside Bakery, goat cheese from North Island Creamery, popcorn from Little Lad’s, and tea from Cup of Sea.
►Certifications & Verifications
Maine Coast Sea Vegetable products are certified organic.
- Maine Seaweed Council
- Rockweed Ecology, Industry, and Management fact sheet (PDF, 4.5 MB)
- Learn about Sea Grant’s Seaweed Production on Mussel Farms in Maine research project.
- Read Sea Vegetable Celebration.