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Location 43o04'11.1"
N 70o53’16.7"W Description:Trophic level oligotrophic (low phytoplankton
with excess nitrogen from sewage discharge, with extensive areas of Zostera marina
[Eel Grass]), maximum depth 17.7 m, average depth 2.7 m. area 23.1 km2. Rapid tidal flushing prevents accretion of
cyanobacteria and phycoplankton. Great Bay Estuary
is a drowned river valley composed of high-energy tidal waters, deep channels
and fringing mudflats. Most of the bay is too shallow for boat
navigation except by small boats with minimal draft. More than half the area of the bay is
exposed as mud flats during low tide.
The entire water volume of the bay is replaced by an estimated average
of nine tidal cycles. Great Bay was formed
~14,000 years ago as the most recent Wisconsin-age glacier receded northward
exposing the coast to rising sealevel.
Currently the major biological habitats in order of area include Zostera meadows,
mudflats, salt marsh dominated by Spartina
patens (Salt-meadow cordgrass in ‘high’ salt marshes) and Spartina alterniflora (Smooth
cordgrass in ‘low’ salt marshes), channel bottom and rocky intertidal with
red and green macroalgae. Not a lake, Great Bay is an inland estuary located on the SE coast of New Hampshire receiving water from five tributaries including the Bellamy, Exeter, Lamprey, Squamscott and Winnicut. It receives tidal water from the Piscataqua River and Little Bay. In
turn, the Piscataqua River receives inland water from two tributaries, the
Cocheco and Salmon Falls rivers. The
mouth of the Piscataqua is Portsmouth Harbor that houses the submarine
drydock called Portsmouth Naval Base. Dates sampled |
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