Invasive Japanese Seaweed Causes Rotten Egg Odor Along North Shore Coast

Residents of Gloucester, Massachusetts, have been troubled by a strong rotten egg-like odor along the coast, which city officials have identified as coming from an invasive Japanese seaweed called Heterosiphonia japonica. The seaweed was pushed ashore and into the Good Harbor estuary by high tides and strong winds from Hurricane Erin, where it has been decomposing and releasing the unpleasant smell. This species, first found on the East Coast in 2008, is known for aggressive spreading and has been linked to fish die-offs. While some residents described the odor as sewage-like and expressed frustration about cleanup efforts, officials explained the smell is a natural result of the seaweed's decay and will fade as it breaks down. The city currently has no plan to remove the seaweed, relying instead on natural tides to clear it away. The invasive seaweed poses ongoing ecological concerns despite being a temporary nuisance to beachgoers.