CHAPTER IV: WILDLIFE HABITATS FOR MISSISSIPPI’S SGCN,
THREATS AND CONSERVATION ACTIONS^275M arine habitats of the Mississippi Gulf Coast
occur in the region beyond the barrier islands
within the western third of the Mississippi-
Alabama continental shelf. Nearshore and offshore
regions of the shelf are roughly two million acres in
size. The shelf extends southward along a gradual
sloping plain of unconsolidated sand, muddy sand
and mud substrates for a distance of approximately
100 miles. It gradually deepens from the shallows
off the barrier islands to a depth of 600 feet along
the outer continental shelf. Over the ages, the
continental shelf has been the recipient of many thousands of feet of sediment deposition from past and
present major river systems. The Mississippi River historically emptied into Mississippi waters. The
Chandeleur Islands are the remnants of its ancient delta. Salinity levels of the water column exceed 30
parts per thousand and turbidity is higher than in Floridian waters. Most of the time, oxygen levels of
the water are sufficient. On occasion a massive current system streaming from tropical regions east of
the South American continent, called the Loop Current, penetrates the region and brings oceanic fauna
that can include invasive species. During abnormal current shifts, nutrient-enriched water from the
Mississippi River may drift into the region and cause hypoxic conditions. Along with estuarine areas,
these northern Gulf waters are known as the "Fertile Fisheries Crescent", an area of remarkably
productive fisheries.
For the purposes of the CWCS, discussion of marine habitats is generally limited to those located within
the three mile territorial boundaries of Mississippi.
This type includes three subtypes: 15.1 Marine Habitats (Smooth Bottoms), 15.2 Hard Bottoms
and Oceanic Reefs and 15.3 Artificial Reefs.
GENERAL CONDITION
A renewed effort in conservation of the rich commercial fishery and shellfish resources of the "Fertile
Fisheries Crescent" and a potential for additional exploitation of the mineral resources of the
northeastern Gulf of Mexico has led to several large ecological research studies on the Mississippi -