Massachusetts

           The rocky intertidal at Northeastern University’s Marine Science Center is located in a protected, bay area.  The majority of Massachusetts’s coast line north of Cape Cod is somewhat sheltered.  Thus, the coastal ecosystems of Northern Massachusetts are of a different quality than the coastal areas of Southern New England.

           Sheltered from the full impact of waves, it exhibits a typical low-flow, protected bay zonation pattern: “A high intertidal barnacle zone gives way in the middle intertidal to an Ascophyllum canopy, which is replaced at low intertidal heights by a zone with considerable free space and patchy mussel beds” (Bertness 1999, p. 238).

            The crabs seem to prefer the mid intertidal area where the majority of the Ascophyllum is located.  Snails are also common in the intertidal, as well as mussels.  These are some of the crabs’ dietary staples.

            The upper intertidal is the barest portion of the intertidal which can only boast barnacles and Littorina saxatilis as its dominant species.

            The lower intertidal has very little Ascophyllum nodosum.  The red seaweed Irish Moss (Chondrus crispus), other red algae and rockweed are the dominant species here.  These seaweeds provide little cover for crabs.
 

The high and mid intertidal zones

The bay

Observe the thick Ascophyllum nodosum canopy