Site Summary: Site Summary: Nahant Bay

Map of the Nahant Bay IBA site

Nominated By:

Rick Heil


4,800 acres

Towns and Counties:

Lynn, Nahant, Swampscott; Essex


town of Nahant, City of Lynn, Department of Conservation and Recreation, Mass Audubon, private

Major Habitats:

60% marine/tidal, 20% urban/suburban, 8% coastal beach, 5% scrub-shrub wetland, 3% early successional shrubland, 3% marine forest, salt marsh, cultural grassland

Land Use:

nature & wildlife, hunting/fishing, fisheries/aquaculture, suburban/residential, research, undeveloped

Serious Threats:

invasive plants, introduced animals, residential/commercial development, disturbance to birds, recreational overuse

Minor Threats:

succession, cowbird parasitism

IBA Criteria:

  • Category 1: Land Birds: The site is an important migratory stopover or seasonal concentration site for migratory land birds (e.g., warblers). Sites may also qualify on the basis of supporting exceptionally high densities of breeding species as shown from point counts or other surveys or if they represent "migrant traps" relative to surrounding areas. Strong consideration will be given to areas with consistently high overall species diversity.
  • Category 2: Waterfowl: The site regularly supports 500 or more waterfowl at any one time. The designation "waterfowl" includes birds such as loons, grebes, cormorants, geese, ducks, coots, and moorhens.

Site Description:

Nahant is essentially an island with a predominantly rocky shoreline connected to the mainland by a rather narrow tombolo along which runs a causeway. The main portion of Nahant lies roughly three miles southeast of the mainland and is well treed but heavily developed, with the exception of a swampy vegetated lowlands area, a golf course, two undeveloped headlands, a cemetery, several small woodlots, and a small thicket owned by Mass Audubon. Slightly closer to the mainland lies heavily developed Little Nahant, connected to the main portion of Nahant by a three-quarter-mile stretch (Short Beach). Nahant Beach (also known as Long Beach) connects the upland portion of Nahant to the mainland at the Lynn shore. This broad, gradually sloping, and sandy beach stretches for some two miles in length. It is backed by a narrow strip of low dunes (adjacent to the causeway), which is vegetated with traditional dune community plants, including Beach Plum, Beach Rose, bayberry, and dune grass, many of these recently reintroduced. The Lynn shore and Swampscott portions are sandy beaches closely backed by a large concrete seawall. At the eastern edge of Nahant Bay, north of East Point, lies Egg Rock, a towering granite ledge. Large algal blooms in Nahant Bay create a thick soupy consistency to the surf in some areas, regularly attracting thousands of shorebirds and Bonaparte's Gulls.

Current Conservation Status:

Recreational beach use is a constant disturbance to roosting and foraging gulls and shorebirds as are jet skis to summering sea ducks. Fortunately, the largest concentration of birds is typically where the most algae accrues, deterring the general public from those areas. It would be very beneficial for roosting shorebirds if even a small portion of the beach near the Lynn border (where the algae most often accumulates) could be roped off as a no-entry area. Unleashed dogs are a frequent problem and often chase roosting or foraging birds. The few remaining woodlots on Nahant are gradually being converted to homesites. Water pollution may or may not be a problem. If water pollution feeds the algal blooms, it may actually be a contributing factor in regard to the bay's attractiveness to shorebirds and Bonaparte's Gulls.

Ornithological Significance:

The Nahant Bay area contains diverse habitat, including sandy beaches, mudflats, mussel beds, a large shallow bay, rocky shorelines, brushland, and thickets. These attract a wide array of bird species including several that occur as migrants and are considered endangered, threatened, or of special concern. Lynn Harbor, which lies on the west side of the causeway, has mudflats and extensive mussel beds exposed at low tide, which attract large flocks of Common Eiders. Thousands of shorebirds and gull species are attracted to the shallow bay and beaches. The bay also hosts large flocks of sea and diving ducks from fall through spring, and a substantial number of immature scoters also summer in the area. Egg Rock has a large colony of nesting Double-crested Cormorants along with large gulls. The undeveloped and vegetated portions of Nahant provide habitat for migrant land birds, serving as a migrant trap, concentrating passerines in both spring and fall due to its insular location several miles off the southern Essex County coast. Large fallouts of neotropical and other migrants comparable to those occurring at Marblehead Neck often ensue, particularly in inclement weather.

State Listed Species:





Northern Parula * * 36 - Spring 2000
Common Tern * * 850 - Fall 2000

* None known

Other Important Species:



Maximum Numbers


Lincoln's Sparrow SM, FM 7 2000
Common Yellowthroat SM, FM 46 2000
Magnolia Warbler SM, FM 22 2000
Ruby-crowned Kinglet SM, FM 30 2000
Dunlin SM, FM, W 400 1996
Purple Sandpiper W, SM 200 1994
Semipalmated Plover SM, FM 550 1996
Bonaparte's Gull SM, FM 3,000+ 2000
Black-headed Gull SM, FM 4 1999
Little Gull SM, FM 5 2000
Laughing Gull FM FM 600 2000
Ruddy Duck FM-W-SM 228 2001
Bufflehead FM-W-SM 885 1999
White-winged Scoter FM-W-SM 1,000+ 2000
Surf Scoter FM-W-SM 135 2000
Common Eider FM-W-SM 3,500 1996
Lesser Scaup W 140 2002
Brant W-SM 208 2000
Great Cormorant W 135 1999
Horned Grebe W 79 2000
Baltimore Oriole SM 26 2000
Rose-breasted Grosbeak FM 15 2000
Black-and-white Warbler SM 15 2000
Black-throated Green SM 19 2000
Black-throated Blue Warbler SM 12 2000
Swainson's Thrush SM 8 2000
Least Flycatcher SM 7 2000
Chimney Swift FM 75 2000
Short-billed Dowitcher SM 630 1996
Sanderling W 800 1996
Sanderling FM 2,800 2000
Sanderling FM 2,400 1998

Other Flora or Fauna of Significance:

None known.

Data Sources:

Published records in Bird Observer, Rick Heil, personal observation

Download the Map:

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