WORKING WATERFRONT • November 24, 2025
We are seeing a shift from kelp to turf algae, progressing up the coast as the Gulf of Maine warms. Kelp forests have largely collapsed in the south, with the boundary of that shift currently around Penobscot Bay. The consequences of such a shift aren’t fully understood, but what we do know isn’t good. Kelp forests provide a number of ecosystem services, and the more biodiverse the composition of kelps the better. There are steps we can take to bolster the resilience of remaining forests, which still cover over half of the expansive Maine coast, mostly to the east of Penobscot Bay. One important step is to ensure that sea urchins remain rare in the ecosystem, to prevent deforestation. ~ Susie Arnold, senior ocean scientist, Island Institute