SUBMERGED AQUATIC VEGETATION 
by 
Drs. Robert J. Orth and Polly J. Penhale 
Virginia Institute of Marine Sciences 
Abstract 
Submerged aquatic vegetation (SAV) systems in the Chesapeake 
Bay are an important natural resource, providing a habitat to 
numerous species, a food source for wintering waterfowl, a buffer 
for shoreline erosion, and a contribution to the primary 
productivity of these shoal areas. These systems have undergone 
natual oscillations in the past but the most recent decline, which 
has affected all species in all areas of the Bay, appears to be 
related to the increasing amounts of nutrients and sediments being 
washed into the Bay. Issues facing researchers and managers today 
are related to conserving existing stands and restoring SAV beds to 
areas that are now devoid of any vegetation. Research should be 
geared to monitoring the status of the Bay SAV communities and to 
refine our understanding of those factors that control the distri¬ 
bution and abundance of SAV. Managers should view transplanting 
programs with caution and give priority to conservation of existing 
beds as opposed to mitigation plans to offset potential SAV losses. 
Dr. Orth: Until recently, SAV systems in the Chesapeake Bay 
has been one of the least studied of the Bay's natural resources. 
Often considered a nuisance because it interferes with human 
activities such as boating or fishing or washes up on the beaches 
of expensive waterfront homes, SAV communities are now being shown 
to be an important part of the Bay's ecosystem. 
SAV systems are appreciated when understood in the context of 
the many roles that SAVs perform in shallower water areas where 
they occur. They are a source of food for wintering waterfowl and 
a habitat and nursery for a diverse array of animals. They 
stabalize bottom sediments and, in same areas, can be a barrier to 
shoreline erosion. They are an important source of primary 
production and are an important element in the nutrient cycling at 
these shoal environments. 
The Bay, with its extensive littoral area and broad salinity 
range supports many different species of SAV. These species are 
distributed along the Bay's salinity gradient depending on their 
different salinity tolerences. Eelgrass which is tolerant of high 
salinities is found in the lower reaches. Watermilfoil, sago 
pondweed, redhead grass, wild celery, coontail, and naiads are less 
tolerant of high salinities and are found in the middle and upper 
reaches of the Bay. 
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