An aggressive and potentially devastating red algae that can damage fisheries has been detected on Appledore Island, Maine, just six miles from the New Hampshire Coast.
The seaweed, Heterosiphonia japonica, is native to Japan and has not been reported elsewhere in Maine The brownish-red stringy plant was first spotted underwater on Appledore in 2011 by undergraduates in the Shoals Marine Lab Underwater Research class, a program of Cornell University and the University of New Hampshire.
The alga grows in the water along the shoreline, then detaches and creates vast, decaying piles in the intertidal zone along the shore. In some locations along the Atlantic coast, Heterosiphonia has covered beaches and threatened tourism with its foul odor. Biologists are also concerned that this seaweed may out-compete native plants, overwhelming local ecosystems and the commercial fisheries they support.
Researchers believe this species was transported to the Atlantic Coast on boat hulls or by shellfish aquaculture. It was first discovered in southern New England on Rhode Island’s eastern seaboard in 2009.
Experts at the lab say the impact of the red algae this far north has yet to be fully felt.
“Other than reports from lobster fishermen about clogged traps and troublesome piles of the seaweed on swimming beaches, we don't yet know the impacts of this seaweed invasion on the coast. But it's moving fast,” said Robin Hadlock Seeley, Shoals senior research associate.