As your eyes drink in the sweeping and lush greenness of the marsh in the summer, you can appreciate the high productivity associated with salt marshes.  But the marsh often keeps its treasures hidden; animals adapted to living in an environment that changes not only every season, but also hour, are not often seen.  A male red-winged blackbird may call and say that this is his marsh, but he is merely a visitor, gone by the middle of the summer.  As the tide enters, a confused cloud of fish dart like a compass in the Bermuda triangle.  Ribbed mussels clinging to the peaty banks gurgle open to take in the phytoplankton that the flooding tide brings.  On the marsh surface, beneath the grass, a greenhead maggot – whose appetite is as voracious – snatches a small crustacean (perhaps a lumbering isopod) in its jaws just before the water arrives.

Below is a checklist of plants and animals found in the marshes of the Plum Island Estuary, Massachusetts.  These lists do not include species found only in the broader estuary such as the open bays.

Emergent plants
(Spartina alterniflora in foreground, cow licks of Spartina patens in background)
Fish
(3-spine stickleback, Gastroteus aculeatus)
Invertebrates
(Streblospio benedicti)
Birds
(Semipalmated sandpiper, Calidris pusilla)