Maine’s coastline extends for over 5,300 miles in length and contains many different intertidal ecosystems that are home to an abundance of life. This life is the basis of multiple fisheries, such as soft-shell clam, blue mussel, lobsters, seaweeds and more. Intertidal ecosystems are any area between high tide and low tide. This means intertidal areas are frequently exposed to different water temperatures, depths, and even exposed to air for multiple hours a day. These zones are connected to the ocean and are susceptible to major changes such as ocean warming, ocean acidification, and variability in biodiversity.
Soft-shell clams use intertidal habitats throughout their life cycle. Soft-shell clams spawn in warm water over a few months in the early spring. The spawn then drifts with ocean and river currents until it grows to a certain size and settles along the mud. Soft-shell clam prefer the lower end of the intertidal zone, where they can be covered with nutrient rich water from the ocean for a longer period of time.
Intertidal ecosystems are also linked with estuary systems. Estuaries, pisipiqe, are areas where a river connects with the ocean. There are 5 major estuaries in Maine including Casco Bay, Muscongus Bay, Penobscot Bay, Frenchman Bay, and Machias Bay. These areas are important travel ways for spawning fish such as alewives, salmon, and others that move up rivers to spawn. They also are extremely susceptible to human activity, as 34% of the state’s population lives along the coast.
Increased human activity near an estuary can lead to water quality problems, which will close down fishing areas and cause health problems for subsistence fishers. This is particularly true for the Passamaquoddy, which drives their work to restore siqonomeqok (alewives). Edward Bassett from the Sipayik Environmental Department created this handout that discusses siqonomeqok as a keystone species that supports broad ecosystem health, such as robust ground fisheries that play an important part in cultural identity for the Passamaquoddy people.