Innovators of the Coast: Bangs Island Mussels

You have to like mussels. The glossy indigo blue shellfish are packed with protein and nutrients. They spend their lives busily filter feeding microscopic organisms from the ocean and putting on weight. Plus, as Bangs Island Mussel Company CEO Matt Moretti realized, blue mussels are a low carbon product that can thrive in Casco Bay.

Matt Moretti and sister Annie of Bangs Island Mussels. BIM photos.

“We started doing this intentionally,” Moretti said, referring to his father Gary with whom he began the business in 2010. His sister Annie joined as chief operating officer in 2020. “Mussels are a sustainable form of protein and you don’t need anything else but a good location to grow them.” Blue mussels are found throughout the Gulf of Maine, whose indented coastline and cold, nutrient-rich water provides many locations for the shellfish to thrive.

From the start Bangs Island Mussels has emphasized reducing the environmental impacts of seafood production. Moretti and his father quickly understood that with mussels they could expand into a thriving business while keeping that mission firmly in mind.

“It was easy to get bigger. Growing more mussels was actually good for the environment. As we grew we kept our sustainability mission in the forefront of every decision,” Moretti said.

The company uses floating rafts, each of which suspend specially designed vertical ropes above the seafloor. Wild mussel spat attach to the lines and grow under the protection of the rafts until they’re ready to harvest.

So far, so good.

Then Moretti added another aquacultured species to its product line, one that provides numerous benefits to the marine environment — kelp.

“We began just after we started the company. We decided to diversify and grow kelp, which is a big product around the world,” Moretti said. “We tried to do various things with it. We ended up drying it and were able to sell it to Atlantic Sea Farms. They were the push everyone needed to grow kelp and were key in developing the market for seaweed in the U.S.”

Kelp is a macroalgae that just loves to suck up dissolved carbon dioxide from seawater. By doing so, the fast-growing kelp affects the water chemistry nearby, producing what is called a “halo effect.” Within that halo area, the seawater’s pH becomes less acidic. That is good news for mussels and other shellfish, whose shells are made weaker by ocean acidification. The kelp itself gets a boost from cultivated mussels that fall to the seafloor and decompose, acting as a type of fertilizer.

“The halo effect is super cool. I was surprised that it was statistically significant. I started thinking about how to farm mussels to maximize this halo effect,” Moretti said. Growing mussels and kelp together benefit each other and the water chemistry but also have an equally beneficial effect on the local area.

Moretti recalls one mussel growing site that initially was nothing more than a muddy, silty bottom. The company has grown mussels and kelp there for many years now and the evolution of the seafloor has been dramatic. “There’s incredible biodiversity and habitats there now,” Moretti explained. “The kelp provides shade and protection from predators. The rafts have other creatures living on them and on the lines. The lines make a little benthic habitat like roots in the ground. And there are mussel beds now on the seafloor loaded with creatures.”

Bangs Island Mussels relied on Atlantic Sea Farms to buy their kelp for many years until the company shifted its focus in 2025, leaving Moretti with the capacity to produce a great deal of kelp and a limited market.

Necessity is the mother of invention along the Maine coast. Moretti, following the company’s mission, found a new use for the kelp. “We are introducing this year a biostimulant for the land. It’s similar to fertilizer but not the same,” he said.

Fertilizer provides a calculated amount of nitrogen, phosphorus and potassium. A biostimulant helps plants better absorb and use those resources. Kelp-based biostimulants also provide trace elements and other compounds to improve growth. In addition, use of biostimulants can reduce the need for commercial fertilizers.

Moretti is excited about the ecological cycle represented by using kelp as a land product.

Ocean-grown kelp absorbs carbon dioxide. As a biostimulant, it is applied to the land. Plants take it up, grow and absorb carbon dioxide themselves through photosynthesis, then die and decay into the soil. Those nutrients in the soil are eventually washed back into the ocean via rivers and streams. “You remove petroleum-based fertilizer from the land,” Moretti said. “It’s in keeping with our dedication to growing highly nutritious food in the least harmful way.”

It may look simple — grow wild mussels in cold, rich Maine water — but as with many things, it takes constant vigilance by Moretti and the company’s employees to stay true to the Bangs Island Mussel goal of producing sustainable seafood in the least harmful way. Whether it’s using biodiesel in the workboats or biodegradable material for packaging, Moretti keeps his eye on the company’s mission while keeping his business successful.