Estuarine Intertidal Mixed-Fine: Lagoon, Mesohaline and Oligohaline

This habitat occurs in lagoons which are nearly completely separated from tidal influence by a berm. Salt water enters the lagoon by occasionally over-topping or breaching the berm, or seeping in subsurface. There is always a source of freshwater and usually horizontal salinity gradients.  Substrata are silt and muck.

Diagnostic Species

Three marsh communities occur in this habitat:  (1) Scirpus maritimus; (2) Scirpus acutus; and (3) Typha latifolia. Scirpus maritimus usually occurs in higher salinity (mesohaline) areas, while the other two communities are found in more oligohaline conditions.  However, salinity gradients occuring in this habitat sometimes permit all three communities to be located in a single lagoon. The latter two communities can also occupy the oligohaline portions of a euhaline lagoon.

Common Associates

Eleocharis palustris.

Sites Surveyed

Foulweather Bluff Preserve, Watmough Bay, Alec Bay.


Kunze, 1984; Cornelius, 1983.