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PIs: Lawrence P. Rozas and Thomas J.
Minello Although the habitat function of seagrass
is well established, relatively few habitat
assessments have included species of
submerged aquatic vegetation (SAV) that
occur in low-salinity estuarine waters.
Moreover, SAV communities in oligohaline
regions of estuaries along the northern Gulf
of Mexico have almost been completely
overlooked.
Vallisneria americana (wild celery or
tapegrass) is a common species of SAV that
is widespread in low-salinity estuarine
areas. Although the total areal coverage of
Vallisneria in estuaries along the
northern Gulf coast is unknown, this species
may occupy large areas at some locations.
Estuaries in Louisiana, particularly those
receiving freshwater from the Mississippi
River, contain sizable shallow, low-salinity
areas where Vallisneria can exist.
Research documenting the habitat value of
Vallisneria beds for fishery species is
urgently needed. This habitat is often
located near developed areas where grass
beds are vulnerable to expanding human
populations. On the other hand, restoration
efforts in Louisiana could have a positive
effect on Vallisneria habitat. Large
river diversions planned to combat coastal
landloss may significantly increase the size
of the area in which Vallisneria can
exist by freshening coastal waters
previously too saline to support this
vegetation. An assessment of the nursery
value of Vallisneria habitat is
required to determine its role in supporting
coastal fisheries and necessary to develop
sound management plans for estuaries and
estuarine-dependent fishery species.
The objective of this project is to evaluate
the role of Vallisneria beds in
providing nursery habitat for fishery
species. In September 2003 and May 2004, we
collected nekton samples from three adjacent
habitat types (Vallisneria beds,
tidal marsh, and nonvegetated subtidal
bottom) within Little Lake in the Barataria
Estuary. Nekton densities will be quantified
and compared among these habitat types to
assess the relative habitat value of
Vallisneria beds.
Publication:
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