Our Estuary
An estuary is located where the rivers meet the sea-where
salt and fresh water mix to form brackish water. Technically, "an estuary is a partially enclosed body
of water where saltwater from the sea mixes with the freshwater from rivers,
streams and creeks. These areas of
transition between the land and the sea are tidally driven, like the sea, but
sheltered from the full force of ocean wind and waves, more like a river. Estuaries are generally enclosed in
part by the coastline, marshes and wetlands: the seaward border may be barrier
islands, reefs and sand or mud flats." (See www.estuaries.gov) Estuaries occur along the edges of the Earth's one big ocean.
The Grand Bay National Estuarine Research Reserve (GNDNERR)
is a marine protected area located in extreme southeastern Mississippi in Jackson County near the small
community of Pecan (see map). The GNDNERR is comprised of approximately 18,000
acres, found chiefly within the Grand Bay National Wildlife Refuge and the Grand Bay Savanna
Coastal Preserve. This reserve contains a variety of wetland habitats, both tidal and
non-tidal, such as pine savannas, salt marshes, saltpans, bays and bayous as
well as terrestrial habitats that are unique to the coastal zone such as
maritime forests.
Healthy estuarine salt marshes and fire-maintained pine
savannas are some of the most biodiverse habitats in North America, and the
reserve is fortunate enough to contain considerable amounts of both. These
habitats support many important species of fish and wildlife. Commercially and
recreationally important species of finfish and shellfish such as brown shrimp,
speckled trout and oysters abound here.
Sea turtles, bottlenose dolphin and, on occasion, manatees can be found
in the deeper waters of the reserve. Many species of carnivorous plants and
orchids can be found in the higher savanna habitats.
Management
The GNDNERR was established in 1999 and has been managed
ever since through a unique local, state and federal partnership designed to
promote estuarine research and education within Mississippi's Coastal Zone and
its adjacent ecosystems. The major partners of the GNDNERR include the
Mississippi Department of Marine Resources, the Mississippi Secretary of
State's Office, Mississippi State University, The Nature Conservancy, the
United States Fish and Wildlife Service and the University of Southern
Mississippi. Additionally, a
Citizens Advisory Board has been established to assure that the concerns of the
local citizens are adequately addressed by the Management Board.
Seventy-five percent of the property located within the
reserve's boundaries is owned by public agencies. Originally, the State's
portion of the Grand Bay NERR was designated as the Grand Bay Savanna Coastal
Preserve. The federal portion of
the reserve is made up of some of the lands that fall within the Grand Bay
National Wildlife Refuge (see boundary map). This national refuge was established by
the U.S. Fish and Wildlife Service in the early 1990's to protect the nation's
last and largest remnant of wetland pine savanna habitat. The Grand Bay NERR is
located completely within The Nature Conservancy's (TNC) Grand Bay Savanna
project area. Because of the great
biological significance of this area, TNC has dedicated this bioreserve as one
of its Last Great Places in America.
This TNC program encourages communities to protect entire landscapes,
not just selected areas of high biodiversity.
The lands within the Grand Bay NERR are classified as either
core areas or buffer areas. The
core area (outlined by yellow on the above map) consists of approximately 12,
800 acres of estuarine tidal marsh, tidal creeks or bayous, shallow, open-water
habitats, oyster reefs, seagrass beds, maritime forests, salt flats, sandy
beaches and shell middens. These protected core lands are extremely important to
the functioning of the estuarine ecosystem; and include "ecological units of a
natural estuarine system which preserves, for research purposes, a full range
of significant physical, chemical and biological factors contributing to the
diversity of fauna, flora, and natural processes occurring within the estuary".
The buffer area
(outlined by blue above) consists of approximately 5,600 acres of tidal marsh,
scrub shrub, pine flatwood and wet pine savanna habitats. Buffer areas are defined as "areas
adjacent to the core areas that provide additional protection for
estuarine-dependent species."
Additionally, a small portion of intertidal marshes located adjacent to
the boat ramp at Bayou Heron is also included in the buffer area. This disturbed area currently provides
the only publicly-owned, waterway access point within the boundaries of the GNDNERR. Properties located within both
the core and buffer areas that are not currently owned by one of the partners
of the reserve have been identified and attempts to secure these parcels from
willing buyers are continuing.
Many of the habitats
within the reserve are considered by law to be coastal wetlands. In Mississippi's Coastal Wetlands
Protection Act, coastal wetlands are defined as
"all
publicly-owned lands subject to the ebb and flow of the tide; which are below
the watermark of ordinary high tide; all publicly-owned accretions above the
watermark of ordinary high tide and all publicly-owned submerged water-bottoms
below the watermark of ordinary high tide and includes the flora and fauna on
the wetlands and in the wetlands."
Mississippi's
coastal wetlands are important resources, not just for the state, but for the
nation as well. Wetlands provide
livelihoods and recreation for coastal residents and their visitors. They serve as habitats and supply
nutrients for many marine species.
They serve as buffer zones for hurricane protection and places of
shelter for animals. Tidal
marshes, a type of coastal wetland, function as filters, removing pollutants
such as sewage and surface run-off which otherwise would flow into the
Mississippi Sound and degrade our state's marine aquatic resources. Because of
the importance of our coastal resources the Mississippi Coastal Wetlands
Protection Act declares it
"to be the public policy of this state to favor the
preservation of the natural state of the coastal wetlands and their ecosystems
and to prevent the despoliation and destruction of them, except where a
specific alteration of specific coastal wetlands would serve a higher public
interest in compliance with the public purposes of the public trust in which
coastal wetlands are held."
This act
establishes a permitting and compliance review process administered by the
Mississippi Department of Marine Resources (DMR) in cooperation with the MS
Department of Environmental Quality, MS Department of Archives and History,
Mississippi Secretary of State's Office and the U.S. Army Corps of Engineers. Those wishing to impact the coastal
wetland must first receive permission from the DMR.
Cultural History within the Grand Bay NERR
Archeological evidence indicates that the lands within the
Grand Bay NERR were occupied as early as 4,500 years ago. Early aboriginal people probably
utilized the waters for fishing and the adjacent lands for hunting, gathering
and refuge as evidenced by the numerous earth and shell middens that have been
located within the reserve.
Recent civilizations have constructed homes along the bayous, especially
Bayou Cumbust, and continue to utilize the waterways for commercial and recreational
fishing and recreational boating. However, many of the homes were destroyed in
Hurricane Katrina, and it is uncertain at this time how many of these
landowners will rebuild.
In the early 20th century, many of the pine
savanna habitats that are located north of the inhabited bayou waterfront
properties were disturbed when local landowners planted them as pine
plantations and began suppressing the fires that were necessary for these
habitats' natural development. Many
of these lands have now been acquired by the U.S. Fish and Wildlife Service, and
the disturbed sites are being restored to their former condition through controlled
fire management.
The western border of the refuge was developed into the
Bayou Casotte Industrial Park in the early 1960's. Chevron U.S.A. Oil Refinery, Mississippi Phosphate Company
and the old Jackson County Airport are examples of industries that are located
immediately adjacent to the reserve.
In addition to operating their refinery, Chevron U.S.A. has supported
and contributed to the development of the GNDNERR and maintains several
hundreds of acres of conservation lands located immediately adjacent to the
western boundary of the refuge.
If you would like to learn more about the history of Jackson County, please visit the illustrated timeline.
^TopPhysiography and Geology
The Grand Bay NERR lies within the gently sloping, lower Gulf
coastal plain. It is thought that the Pascagoula River once flowed through the
reserve and emptied into Point Aux Chenes Bay, forming a rich delta. Sometime after the sea reached
its current level, however, the river changed its course and now flows into the
Mississippi Sound approximately five miles west of the reserve. This natural diversion of the river
water and its associated sediments away from Point Aux Chenes Bay has led to a
condition that has resulted in the retrograding (erosion) of this estuarine
system. Currently, the only major
channels within the NERR are Bayou Cumbust and Bayou Heron. These tidal bayous are relatively small
and have slow-moving, tea-colored waters that are rich in tannins, a natural by-product of decaying vegetation.
The
Grand Batture Islands located at the mouth of Point Aux Chenes Bay once formed
a significant chain of islands on the southern boundary of the reserve. However, between the years of 1853 and
1950, coastal erosional forces ate away at the islands until today they are
little more than giant mud lumps.
Because these islands are no longer large enough to protect the bay from
high winds and waves, the sensitive coastal salt marshes located along the
fringe of the bay are being eroded away at an alarming rate (over 30 feet per
year).