The Maine coast is recognized as a critical staging area for migratory shorebirds, a stopover on their long migration route. The shorebirds rely on mudflats rich in invertebrates for feeding and gravel bars or sand spits for roosting, both of which are susceptible to disturbance and environmental contaminants. Twenty-eight species of migratory shorebirds have been surveyed along the coast, several of which are of special concern in Maine. Seabird populations are increasing in response to management or as species naturally recover from over utilization in the late 1800s and early 1900s. Marine mammals included on the federal endangered or threatened species list are protected within Maine.
Recent surveys indicate the harbor seal population is doing well and has been increasing.
Gray seals have also been increasing along the Maine coast and recently established a pupping colony. Harp seals and hooded seals have been seen more frequently. While the restoration of Maine's seal population is celebrated by most, there are some problems. Salmon farmers downeast have fought long to protect their penned fish from attacks from seals. As the numbers of seals grow, so do the number of attacks on farmed salmon.