State regulators are drawing up the first management plan to protect rockweed, a common seaweed on the Maine coast that supported a $20 million industry in 2012 and is likely to attract even more intensive harvesting as global markets expand.

The number of licensed rockweed harvesters in Maine climbed from 29 to 59 between 2004 and 2012, when harvesters gathered about 14 million pounds of the marine plant. Rockweed, which clings to rocks in the intertidal zone, sells for only 3 cents a pound at the dock. But the harvest was worth $20 million after it was processed for use in a range of products: Pharmaceuticals, nutritional supplements, cosmetics, fertilizers, animal feed and horticultural additives.

“We’re a young fishery … but we have a big bright future in seaweed harvesting,” said Bob Morse, founder of Atlantic Laboratories Inc. of Waldoboro, the parent company of North American Kelp, which processes rockweed. “If this was China or Japan, we’d have a $3 billion seaweed industry here.”

A 13-member team assembled by the Department of Marine Resources will take a final look at the proposed management plan on Jan. 7, before sending it on to the Legislature’s Committee on Marine Resources for additional comment. The rockweed harvest is one of about 20 marine fisheries or industries the department plans to review for possible regulation and oversight.

The team, drawn from the marine resources department, researchers, academics, harvesters, processors and conservationists, has worked on the draft plan for about six months.



According to the draft document, the plan is designed to provide recommendations – but not regulations – for long-term management of rockweed harvesting.

Rockweed – a species of seaweed known as Ascophyllum nodosum – has become more marketable in recent years, in part because of new uses for the resource.

The purpose of the 51-page plan is to familiarize residents with the fishery and to outline guidelines for harvesting that will support the long-term health and sustainability of rockweed as a fisheries resource, said Linda Mercer, a member of the management team and director of the Bureau of Marine Science.

Currently, rockweed harvesters in Maine must be licensed, but there is no limit on where or how much they may cut, rake or remove rockweed with certain types of mechanical harvesting.

Only the Cobscook Bay Rockweed Management Area in the Eastport-Lubec area is off limits, and under the plan it would remain protected, Mercer said.

Other conservation and research areas could be protected, but the plan does not designate where those might be, and establishment of such zones is outside the team’s authority, she said. Even specific recommendations for such areas would take at least six months to complete, Mercer said.


In the past, regulation of rockweed harvesting has largely been limited to licensing by the state, a range of federal and interstate agreements and rules, some colonial-era ownership laws and the commitment of harvesters to preserve the resource, Mercer said.

“Rockweed is important food, shelter and spawning habitat for a lot of species in Maine,” said Laura Minich Zitske, a wildlife ecologist with the Maine Audubon Society. “It’s not just a resource for us to extract and use … it’s an essential part of the ecosystem.”

Morse, who has been harvesting seaweed for more than 40 years and now is one of the larger Maine-based processors, said the harvesters and industry already have managed the fishery well.

“We have 30 percent more (seaweed) than when I started back in the ’70s,” Morse said.

But rockweed and other seaweed fisheries are likely to attract more interest as the future of Maine’s dominant fisheries, including the more than $300 million per year lobster harvest, becomes less certain due to changing seawater temperatures, salinity, disease and erratic weather conditions in the Gulf of Maine.

To respond to that growth will require a strong knowledge base and prudent management, industry and state officials agreed.


Some unanswered questions about rockweed are being explored under a nearly $100,000 state grant to the Maine Maritime Academy.

The money will fund research into which organisms feed on two species of rockweed and how they fit into and contribute to the near-shore food web and the ecosystem as a whole, said project director Jessica Muhlin, associate professor of marine biology at MMA.

The research will focus on the times and places rockweed undergoes reproduction, Muhlin said.

Because the reproductive processes take place outside the organisms rather than within, a huge amount of material – eggs, sperm, fertilized eggs and mucilage – is spewed into the water and serves as food for some of the estimated 150 species of animals that live in or rely on the canopy of rockweed, she said.

The research will track when and where that material travels within the larger food web, Muhlin said.

It may offer clues to understanding of rockweed that now are lacking but sorely needed to avoid trouble in these intertidal-zone species before it starts.


“They’re not imperiled but they’re ecologically very important,” Muhlin said.

“It’s a wonderful renewable resource,” said Zitske, the Audubon ecologist. “But like anything, I’m glad there’s a management plan that people are thinking about for it.”

North Cairn can be reached at 791-6325 or at:

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