BANGOR (AP) – Concerns about commercial harvesting of a brownish-green seaweed called rockweed in Cobscook Bay has prompted calls by some Washington County residents for a state-imposed moratorium.

Critics of the harvesting have complained about unusual amounts of cut rockweed floating in the bay in easternmost Maine. Activists are seeking to halt the harvesting until studies can determine its impact on the bay’s overall health.

The stringy seaweed peppered with air bladders is used in products that range from foods and beverages to cosmetics and fertilizers.

Although harvesters must report their takes at the end of the season, Maine has no rockweed harvesting regulations other than a cutting height of 16 inches or to the point of the first branching of the plant, “whichever leaves more of the plant,” said Peter Thayer, a scientist with the state Department of Marine Resources.

A study is under way on animals and plants that live within the seaweed canopy, Thayer said. That study is scheduled to be completed by next spring.

Residents in the Cobscook region have expressed worries about the harvest’s impact on marine life and their own livelihoods. They also complain that loose rockweed is getting tangled in boat propellers and putting fishermen in harm’s way.

“Our ocean is our life,” said licensed clammer Julie Keene of Lubec, who took part in a protest last month in Lubec. “The ecological balance that needs to be maintained in the bay’s ecosystem is crucial.”

A Canadian company that has harvested rockweed in Cobscook Bay since 2001 denies that its activities are harmful. Acadian Seaplants of Dartmouth, Nova Scotia, said the percentage of biomass harvested each year is well below the average annual biomass growth.

“We are managing the resource in a very responsible, sustainable and in a long-term manner,” said President Jean-Paul Deveau.

The company said commercial rockweed harvesting has already been the focus of extensive studies.

“These studies have ranged from research on the general ecology and diversity of the intertidal zone to research focusing directly on rockweed, its relationship to other fisheries and marine life, and on the impact of rockweed harvesting on the rockweed biomass, production and its use as habitat,” according to a fact sheet provided by the company.

Rockweed accounts of the bulk of Maine’s 2007 seaweed harvest of nearly 7.5 million pounds, valued at $298,887.