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CHAPTER IV: WILDLIFE HABITATS FOR MISSISSIPPI’S SGCN,

THREATS AND CONSERVATION ACTIONS^259

A Continue to restrict/monitor scientific collection of SGCN.

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.

14.2 Mississippi Sound (Smooth Bottom)

„ Value to SGCN - 58

„ Rank - 8th of 17 Marine, Estuarine and Estuarine

Fringe Systems

DESCRIPTION
The Mississippi Sound is considered a lagoon of marine
origin whereas embayments are likely drowned river valleys.
The term “sound” is defined as a water body extending
parallel to the coast that is separated from the open ocean by land. A chain of barrier islands serves as
the outer boundary of the Mississippi Sound. Based on hydrological differences among sections of the
Sound, it is considered to have three zones. The West Sound is fed by higher freshwater inflows. The
Central Sound is an area of poor circulation, little freshwater inflow and experiences extensive tidal
flushing. The East Sound is dominated by water inflow from the Mobile Bay and Petit Bois Pass.
General westward current movement on both the northern and southern shores of the Sound is sufficient
to induce appreciable sand movement along the shoreline. Salinity levels are within the polyhaline
range and are typically lowest along the mainland where levels fluctuate more widely. Seven habitat
types have been described for the Mississippi Sound. They are classified on the basis of differences in
depth and texture of substrate. Each supports a discrete assemblage of benthic organisms that help to
define the ecological communities. Nearshore communities are those with depths less than 6.5 feet;
offshore communities have depths greater than 6.5 feet. The near- and off-shore zones are subclassified
into three types: mud, sandy mud and sand bottom types. The seventh habitat type of the Sound is the
tidal pass, which is discussed in subtype 14.4 (Barrier Island Passes). The Mississippi Sound supports
important stocks of fish and invertebrates, providing foraging areas for many bird species including
federally endangered brown pelicans, porpoises, marine turtles such as the Atlantic Ridley and
loggerhead and occasionally manatees.

LOCATION, SIZE, CONDITION AND CONSERVATION STATUS
NGM

The Mississippi Sound is a linear body of water about 12 miles wide that extends the length of the state
into Alabama. It is comprised of a variety of subtidal habitats that are recognized by their differences in
depth and substrate texture. The Sound is circumscribed by a variety of subtidal and intertidal estuarine