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CHAPTER IV: WILDLIFE HABITATS FOR MISSISSIPPI’S SGCN,

THREATS AND CONSERVATION ACTIONS^262

A Control exotic and invasive species (plant and animal).

A Provide public education about conservation of SGCN and/or their habitats.

A Discourage incompatible recreational uses.

A Encourage appreciation of SGCN and their habitats by providing public access and compatible
recreational activities.

A Encourage proper disposal and cleanup of waste and litter.

14.3 Estuarine Marshes

„ Value to SGCN - 107

„ Rank - 1st of 17 Marine, Estuarine and

Estuarine Fringe Systems

DESCRIPTION
Intertidal salt, brackish and tidal freshwater marshes
create a fringe along the coast and barrier islands
and cover substantial lowland flats along mouths of
streams and bays. Tidal marshes are situated on organic muck substrates that are often interlaced to
varying degrees with mineral horizons that were likely deposited during storm surges. Some levees and
reworked mineral sediments are situated along the mouths of larger coastal streams. Saltmarshes are
characterized by their low position within the tidal zone and their increased exposure to higher water
salinities. Salt pannes or flats represent a zone of sandy hypersaline soil within saltmarsh vegetation.
They are discussed in subtype 14.5.

Saltmarsh vegetation can be classified into several zones of elevation. The lowest zone situated at sea
level or slightly below is composed of frequently flooded smooth cordgrass marshes that form a narrow
fringe of green shimmering spikes along exposed shorelines and outer sections of tidal creeks and bays.
The plants are often partially submerged and are flooded on a daily basis. With a slight increase in
elevation, frequently flooded marshes are superseded by irregularly flooded marshes. Irregularly
flooded saline marshes are situated at intermediate levels, just above mean high water of the tidal zone.
They are dominated by black needlerush, which forms a near monoculture of thick, tall, dark olive
green, sharply-pointed leaves. The intermediate marsh covers broad estuarine flats.

At supratidal levels, a zone of saltmeadow cordgrass is encountered. Brackish marshes differ somewhat
from saltmarshes. They are situated in areas of moderate salinity and experience greater protection from
storm surges. These moderating influences enable the establishment of a higher diversity of plants. In
contrast to salt marshes, tidal creeks within the brackish marsh zone are usually fringed with wildrice
and/or big cordgrass, especially along the bayous of riverine estuaries. Oligohaline marshes are