The predominant habitat types of the Northeast Region include the rocky shores of New England, the sandy beaches of the Mid-Atlantic, and the extensive salt marsh system that runs along the back bays and river basins form Maine to Chesapeake Bay. The nation's living marine resources depend on the rivers, estuaries, marshes, tidal flats, and shallow waters of these areas. It is the interconnection of these habitats that make them so biologically productive. Atlantic salmon, American shad, and striped bass are among the most sought after anadromous species which are dependent on riverine habitat for early lifestage survival. American eels, our only catadromous species, grow in river systems after hatching in the Sargasso Sea.
Phytoplankton are the single celled plants upon which primary consumers such as small fish feed.
The primary consumers are, in turn, preyed upon by carnivorous species, including many commercially-important fish and shellfish. Estuaries are formed where rivers meet the ocean and salt water is diluted by fresh. The input of nutrients, fresh water, and abundant food combine to provide unique, shallow habitats. Estuaries provide sanctuary from the harsh action of ocean currents and waves. These systems are often fringed by salt marshes and tidal flats and may contain valuable beds of subaquatic vegetation such as eelgrass and widgeongrass.