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Shoals Lab vulnerable to rockweed harvests

A Shoals Marine Lab researcher believes that commercial harvest of rockweed, a brown seaweed that anchors to rocks in intertidal zones in the Northeast, poses a serious threat to the community of 150 species associated with this seaweed habitat. Rockweed, or Ascophyllum nodosum, serves as a living laboratory for students and faculty at the Shoals Marine Lab on Appledore Island, six miles off the New Hampshire coast.

Last month, Robin Hadlock Seeley, assistant director for academic affairs at Shoals and a Cornell senior research associate, received a $28,000 TogetherGreen Innovation Grant from Toyota and the National Audubon Society to continue a project to preserve the habitat for local fisheries and other wildlife in Cobscook Bay, Maine.

Seeley has been raising awareness about issues related to commercial rockweed harvests performed with manual rakes or machine cutters that can remove up to 50 tons a day destined for use in fertilizers, agricultural feeds and other products, including cosmetics.

"There are no laws or regulations that protect the seaweed in the intertidal zone on Appledore Island from being cut down, and that intertidal habitat is our main teaching laboratory," Seeley said.

Are such harvests legal in the state of Maine? Are they sustainable? Seeley says these are the two main issues surrounding the commercial harvest.

Maine's Underwater Rockweed Forest from David Brown on Vimeo.

Seeley and the organization she co-founded, the Rockweed Coalition, have helped establish a law protecting rockweed in conservation areas of Cobscook Bay, Seeley said, but the rest of the Maine coast has no restrictions other than a regulation limiting the cut to 16 inches above the rock surface.

In Maine, private landowners own the intertidal zone, the region between high and low tide. Shellfishing such as clamming and collecting bait worms are part of public trust rights to use the intertidal zone, but cutting marine plants is in a gray area, Seeley said.

Companies claim their harvests are sustainable, because rockweed will eventually grow back over time if it is cut to 16 inches. But Seeley points out that the industry's definition of "sustainable" harvests does not account for ecosystem impacts, including impacts on the 150 species that depend on rockweed habitat. Rockweed provides nutrient cycling, energy to food webs, and habitat for fish, waterfowl, algae, shellfish and other invertebrates, according to a 2012 study on the sustainability of seaweed cutting by Seeley and William Schlesinger, Ph.D. '76, published in the Annals of the New York Academy of Sciences. The study concluded that long-term data are needed to determine the effects of seaweed harvesting on marine life, and strict regulations and monitoring will be required.

Seeley worked with filmmaker David Brown '83 to produce a short film on issues of rockweed cutting as part of her TogetherGreen Conservation Leadership Award, and they are collaborating on a longer film addressing the value of intact habitats for supporting traditional fisheries and the communities that depend on those fisheries.

Since 1966, Shoals Marine Lab, which is administered by Cornell and the University of New Hampshire, has offered hands-on marine science educational experience for undergraduates.

The shores of Appledore Island, Maine, home to the Shoals Marine Lab, are threatened by an invasive red algae (Heterosiphonia japonica) that has been found only in southern New England to date.

The seaweed was discovered on Appledore by a long-term research project begun 40 years ago when the Shoals Marine Lab was established. The Shoals Intertidal Transect Project details the distribution and abundance of organisms in exposed and protected rocky intertidal habitats on Appledore Island. Through this annual survey of the biota of Appledore Island in southern Maine, Shoals Marine Lab acts as a sentinel for invasive species expanding from the warmer waters of southern New England.

The aggressive red algae hail from Japan and outcompete native species. Researchers believe this species was transported to the Atlantic Coast on boat hulls or by shellfish aquaculture. It was first discovered on Rhode Island's eastern seaboard in 2009 and has been moving north. Heterosiphonia japonica was first identified on Appledore Island in 2011 from species collected by undergraduates in the SML Underwater Research class and confirmed sightings occurred again in 2012.

The algae grow in the water along the shoreline, then detach and create vast piles in intertidal zones that rot and stink.

"It is currently present in large enough amounts in limited areas of Appledore's shoreline to impact the intertidal zone. We don't know what those impacts will be," said Robin Hadlock Seeley, Shoals senior research associate.

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