Rope Grown Maine Mussels

Sustainable. Local. Fresh. Natural. Healthy.

About Calendar Island Mussel Company

Calendar Island Mussel Co. is a registered aquaculture company located in Portland, Maine. It was formed specifically and only to raise and harvest sweet, succulent rope-grown blue mussels in the deep, clear ocean waters of Maine.

Mussel Inspection

Mussel Inspection


Portland people know their food and Portland is famed for being a “foodie” small city with its abundance of excellent restaurants and nationally acclaimed chefs. Chefs from here to Washington D.C. to Chicago know that rope grown mussels from Maine waters can’t be beat for taste and quality. Our staff is dedicated to growing and supplying our customers with the best blue mussels on the planet. We promise that our mussels will be fresh, delicious and beautiful.


At Calendar Island Mussels we strive to ensure that consistent taste and overall high quality of each mussel through natural and sustainable methods. From the collection of seed produced in nature, to harvesting and grading of market sized mussels, we use sustainable growing techniques developed and used in Spain for decades.

Calendar Island Mussels

One Of Our Calendar Island Raft Sites

We strive at all times to be environmentally conscious; leaving as little imprint on the natural environment as possible. We raise our mussels in a sustainable and eco-friendly way:


Mussel aquaculture, the farming of mussels, has been ongoing for centuries in many forms. The largest farming countries are China and Spain. Most of the mussels consumed in the United States come from the Atlantic Provinces of Canada, New Zealand and Chile. There are several species of mussels around the world. In the eastern United States, including Maine we grow the blue mussel (Mytilis Edulis).

Today mussel farming includes: bottom culture, the seeding of the bottom of the ocean in relatively shallow waters and hand harvesting or dragging the bottom from a boat to harvest; AND, suspension culture – growing the mussels on ropes (“rope grown mussels) hanging or suspended in the ocean, not in the mud/sand at the bottom. Growing mussels on ropes in suspension is more environmentally friendly and produces a faster growing, plumper, more consistently tasty mussel.

Mussel Seeding Lines

Speed Growing Seeding Lines

Here at Calendar Island Mussel Co. we grow our mussels on ropes vertically suspended in the water in the top 40 feet of the water column. These ropes are first used to collect microscopic mussel larvae, or “seed” that naturally float near the surface of the water once or twice per year. The larvae stick to rope naturally as they do to rocks, seaweed, etc… After three months the mussels on the rope can be seen and look like flakes of pepper (“pepper seed”). After about eighteen months their meat is full enough to be harvested. The ropes are lifted from the rafts into our specially designed boat, stripped off the ropes and cleaned using several different tools/ equipment that tumble them in ocean water. The mussels are then hand graded and hand packed into 10 lb and 30 lb bags, immediately placed in ice and then delivered to their buyers / consumers.