Habitats are places where plants and animals live, feed, find shelter, and reproduce.  Due to topography and wide tidal variations characteristic of the Gulf of Maine, Maine has the most extensive intertidal habitats (the area between the high and low tide lines) found along the Atlantic Coast of the United States.  Casco Bay's intertidal area includes nearly 200,000 acres of clam flats.  Along the bay, salt marshes, including many small fringing marshes along the water's edge, filter stormwater from upland developments and help moderate nutrient flow to adjoining waters.  These marshes also act as buffers during storms and help to reduce damage from flooding.

Aproximately 150 species of waterbirds inhabit Casco Bay and the 500 acres of rocky shore in Casco Bay provide habitat for a wide range of species: from seaweeds, lobsters, mussels, barnacles, and crabs to starfish and seals.

Plants, which support the food chain, are an important part of subtidal habitats in Casco Bay.  These are submerged habitats located below the mean low-water line.  One particularly sensitive plant, eelgrass, is considered an indicator of ecosystem health.  Casco Bay has the largest and densest concentrations of eelgrass mapped along the coast of Maine, with over 8,000 acres of beds. 

Casco Bay contains 758 island, islets, and exposed ledges at mean high tide, some of which are important habitat for colonial nesting sea birds.

Throughout the Casco Bay watershed, there are more than 1,356 miles of rivers and streams.  Streams provide important habitats for fish, including anadromous species (fish like alewife and smelt that spawn in fresh water then move into salt water).  The freshwater systems provide habitat for a wide variety of species including the bald eagle, belted kingfisher, loons, black duck, spotted sandpiper, shad, trout, bass, perch, and pickerel as well as mammals like muskrat, beaver, and river otter.

Human activity can threaten habitat in numerous ways -- through direct loss, fragmentation, encroachment, disturbance, diminished water quality, altered drainage patterns, and creation of barriers.  In addition, invasive non-native species can threaten the quality of habitat by outcompeting native species for space and resources.  Global warming can impact habitat by altering habitat characteristics (e.g., temperature, precipitation), affecting the range of habitats available to native species, and opening habitats to invasion from non-native organisms.

Humans sharing the ecological community of Casco Bay have a responsibility to conserve our natural habitats.   The Casco Bay Estuary Partnership works to conserve habitat using a multi-pronged approach: through habitat restoration projects (including on-the-ground field work, assessment, mapping and inventory development); through habitat protection (including assistance with property acquisition and conservation easements, and mapping conserved habitat areas); and by developing educational tools and indicators to address impacts from climate change and invasive species.

Click here or on the Current Projects button to the right for examples of the habitat conservation activities that CBEP and our partner organizations are supporting.