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Chapter 1 - Introductionof shorebirds such as osprey, herons, egrets, oyster catchers,plovers, terns, sandpipers and gulls.The shallow estuaries and embayments are home to awide variety of migratory marine species that give thistemperate region its unique character (Weiss 1995). Largemammals such as harbor seals and harbor porpoises havebeen frequently documented migrating close to shore. Theregion is also home to a variety of migratory fishes, manyof which are commercially and recreationally importantspecies including bluefish, bass, toadfish, flounder, shad,herring, menhaden and mackerel.The subregion is well known for its productive estuariesthat have historically supported thriving shellfish industriesand a cultural history centering around the productivemaritime industry. Subregional favorites includeoysters, hard and soft shell clams, razor clams, bay scallops,and quahogs. Horseshoe crabs can be found on theshorelines throughout the landscape, as well as blue crabs,spider crabs, and fiddler crabs.Mid-Atlantic Bight BiogeographyThe Mid-Atlantic Bight extends from Cape Hatterasin North Carolina to Sandy Hook, New Jersey and isa transitional area between the rocky shores of NewEngland and gently sloping, warmer South Atlantic. TheMid-Atlantic’s oceanographic features, diversity and ecologyare strongly influenced by two very large estuaries- Chesapeake Bay and Delaware Bay. Like the Gulf ofMaine and Southern New England, the Mid-Atlantic is ahighly productive region of one of the world’s most productivelarge marine ecosystems.The topography of the Mid-Atlantic is characterized asmostly flat, with low relief features such as sandy shoalsand swales, sand wedges and waves, and relict coastalfeatures with major submarine canyons at the shelf-slopebreak. The complex of shoals and swales are importantstructural features supporting biologically diverse andabundant benthic macrofauna, demersal fish, and foragingconcentrations of sea birds, sea ducks and bottlenosedolphins. The shelf is typically covered by a sheet of medium-to-coarsegrained sands with occasional pocketsof sand-shell and sand-gravel sediments (Wigley andTheroux 1981). Natural hard bottom habitat is relativelyscarce compared to the Southern New England and Gulfof Maine subregions. However, coldwater coral patchreef communities with associated structure oriented fishlike black seabass and tautog are present, though poorlymapped at this time.Warm core rings, filaments and mid-water intrusions peeloff the meanders in the Gulf Stream, moving warmer,higher salinity pockets of waters from the slope westwardacross the shelf towards the coast. When thesecurrents cross over topographic highs such as shoals orridges - and notably canyon heads - they create significantcold-water upwellings and extremely productive biologicalevents (Walsh et al. 1978). The freshwater outputs ofthe Chesapeake and Delaware bays function similarly tothe Gulf Stream through their large plumes which collidewith tidal forces to create highly productive nearshore upwellingevents that support diverse marine life.Due to its intermediate position between the cool NewEngland and warm southeastern United States waters, theMid-Atlantic subregion provides a critical migratory pathwaywith abundant forage resources for many migratoryspecies from striped bass to right whales.The Mid-Atlantic’s chain of barrier islands includesroughly 30 inlets, formed by the interaction action ofwaves and currents with mainland drainages and underlyingancient river valleys. These inlets are important ecologicalsystems in the Mid-Atlantic as well, functioning ascorridors between the coastal lagoons and the shelf waters.The Mid-Atlantic’s inlets and lagoons provide criticalspawning areas for sciaenids such as drum, spot, croakerand sea trout, pupping grounds for coastal elasmobrancheslike sandbar shark, dusky sharks and sand tiger, foragingand nursery habitat for all life stages of the bottlenosedolphin, juvenile habitat for loggerhead turtles and lowenergy beaches for horseshoe crab spawning.Northwest Atlantic Marine Ecoregional Assessment • Phase 1 Report 1-