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CASCO BAY PLAN
 
 

Habitats are places where plants and animals live, feed, find shelter, and reproduce. For human members sharing natural habitats, the knowledge of interdependence carries with it a responsibility. Human activity can threaten habitat in numerous ways, through direct loss, fragmentation, encroachment, disturbance, diminished water quality, altered drainage patterns, and barriers. To sustain the health of Casco Bay, we must pursue actions that benefit not only our own species, but also all the "neighboring" plants and animals that share the watershed's ecological community. 

Marine and Estuarine Waters
The marine habitats of Casco Bay cover 229 square miles. The intertidal zone of marine estuarine waters includes a diverse array of habitats from rocky shore to salt marshes and flats. Due to topography and wide tidal variations characteristic of the Gulf of Maine, intertidal areas in Maine are the most extensive along the Atlantic Coast of the United States. Flats are the most characteristic intertidal habitat in Casco Bay, with 11,582 acres of tidal flats. 

Flats are especially important environments because they support a rich and abundant animal community, including commercially harvested clams, sandworms, and bloodworms. Shorebirds, waterfowl, and wading birds feed on flats and in the creeks and shallow subtidal areas near flats. Waterbirds also use the open waters of Casco Bay. Cape Elizabeth in Casco Bay is the boundary for two zoogeographic regions - the boreal and northern temperate zones - for waterbirds. Consequently, a wide variety and unusual aggregation of marine birds occur in Casco Bay. 

Approximately 150 species of waterbirds inhabit Casco Bay, 100 of which occur regularly. The number of waterbirds in Casco Bay varies seasonally from approximately 4,600 to about 32,000. Salt marshes filter stormwater from upland developments and help moderate nutrient flow to adjoining waters. Marshes also act as giant sponges during storms and therefore reduce damage from flooding. 

The 500 acres of rocky shore in Casco Bay provide habitat for a wide range of species, from seaweeds, periwinkles, mussels, barnacles, and crabs to starfish and seals. Waterfowl such as eider ducks use rocky shore habitat for feeding. The composition of the sea bottom (i.e., fine mud, sand, gravel, cobble, boulders, and rock) determines which plants and animals live in particular subtidal habitats. For example, lobsters, crabs, and sea urchins generally live on hard bottom, whereas scallops and worms dwell in soft-bottom areas. Thirty-six species of finfish reside in Casco Bay. The most abundant year-round fish in the bay are bottom feeders such as pollock, sculpin, and skate. The shallow protected coves in Casco Bay provide perfect spawning habitat for fish that deposit eggs on the bottom (e.g., sculpin, winter flounder, rock gunnel, tomcod, and skate). There are numerous marine mammals in Casco Bay including two species of seals, four species of whales, two species of dolphins, and harbor porpoises. 

Plants, which support the food chain, are an important part of subtidal habitats. One particularly sensitive plant, eelgrass, is considered an indicator of ecosystem health. Growing in shallow, clear water with silty sand bottoms (and on some flats), it is used by flounder, cod, striped bass, scallops, crabs, lobsters, and waterfowl as a nursery area, feeding ground, or refuge from predators. Casco Bay has the largest and most dense concentrations of eelgrass mapped along the coast of Maine, with over 7,000 acres of beds. 

Islands
Casco Bay contains 758 islands, islets, and exposed ledges at mean high tide, a few of which are important habitat for colonial nesting seabirds. Uninhabited outer islands often provide prime nesting sites for seabirds, being inaccessible to predators such as fox, mink, and racoons. The bay has 50 seabird nesting islands, of which 17 support nationally significant populations of nesting birds. The 17 major nesting colonies collectively represent more than 15 percent of the states nesting seabird population. There are 41 documented seal haulouts in Casco Bay, on either small islands with no terrestrial vegetation or half-tide ledges that are under water at high tide.

Rivers, Streams, and Freshwater Wetlands
Throughout the Casco Bay watershed, there are more than 1,356 miles of rivers and streams that offer habitat to muskrat, beaver, river otter, belted kingfisher, black duck, spotted sandpiper, shad, trout, bass, perch, pickerel, and salmon. Streams provide important habitats for juvenile fish and for anadromous fish like alewife and smelt, which use them for spawning. The riparian (streambank) zone and the 578 miles of edge habitat next to the shoreline of Casco Bay are important links between the terrestrial (land) ecosystem and the wetlands or water. Many species of birds and mammals use these areas for shelter, feeding, and nesting or raising young. Freshwater wetlands range from marshes and wooded swamps to vernal pools. Like coastal salt marshes, freshwater wetlands afford critical habitat, particularly for deer, beavers, muskrats, raccoons, wood ducks, American bitterns, great blue herons, green herons, leopard frogs, painted turtles, and four-toed salamanders. Freshwater wetlands also play an important role in purifying polluted water and reducing flood damage.

Invasive Species
Invasive species are non-native species whose introduction causes or is likely to cause economic or environmental harm or harm to human health.  Not directly addressed in the Casco Bay Plan, invasive species are an emerging issue in Casco Bay.

What we are Doing

New Meadows Lake Feasibility Study.  In May 2005, the Casco Bay Estuary Partnership (then Casco Bay Estuary Project), in conjunction with the New Meadows River steering Committee, initiated a study to identify and evaluate the feasibility of technical alternatives to improve water quality and enhance the natural resources of the New Meadows Lake.

The Gulf of Maine Coastal Program has identified and mapped important habitat for 9 groups of species, including waterbirds, seabirds, wading birds, fish, eelgrass, cordgrass, marine worms, shellfish and endangered/threatened species. Results are being used to catalyze voluntary habitat protection efforts in the region.

The Casco Bay Estuary Partnership, in coordination with the U.S. Fish and Wildlife Service Gulf of Maine Program and Maine Coast Heritage Trust, provides funds to support habitat restoration initiatives designed to protect important fish and wildlife habitat. Here are a few of the projects  implemented by some of the partners of the Casco Bay Estuary Partnership.

In  August 2003 the Estuary Partnership hosted a team of 25 scientists who conducted a survey of floating docks and piers to find out how many exotic marine species have invaded the coastal waters.

The Estuary Partanership, Maine Sea Grant and Gloria Duclos Convocation on Environmental Sustainability hosted a public education forum on marine invasive species in May 2004.  This forum was a first step in developing a statewide strategy for addressing marine invasive species issues in Maine. The working group spawned from that forum wnt on to create a fact sheet entitled Maine's Marine Invasion (681.14 KB).

The Estuary Partnership supported the expansion of the Maine Horseshoe Crab Spawning Survey in Casco Bay. 

• Plant native vegetation in and around your property to promote a variety of wildlife species (call CBEP for planting ideas, 780-4820).
• Maintain vegetative buffer areas next to water. These buffers provide habitat and act as filters for stormwater and groundwater flow from upland development.
• If you have land that you think has important habitat value contact your local land trust or the Maine Coast Heritage Trust to talk about various options to ensure its continued protection. (often these options provide tax relief or other benefits to land owners)
• Support efforts in your community or region that protect important habitat areas. Become involved in your local land trust, planning board, and or conservation commission.  The Estuary Partnership website has a listing of local volunteer opportunities.
• For more detailed information you can visit the National Oceanic and Atmospheric Administration (NOAA) technical manual online. "Science-Based Restoration Monitoring of Coastal Habitats," provides technical assistance, outlines the steps for developing a restoration monitoring program, and provides useful tools for the development and implementation of sound scientific monitoring of coastal restoration efforts.
• NOAA's Restoration Center has developed a restoration project database to house information on coastal restoration projects.  The database is still under development but will ultimately be searchable by region, state and watershed, and will contain an interactive GIS-based mapping system.  More information about the database and how to add restoration projects to it can be found by visiting the NOAA Restoration Center web site.