Marylandís Bay Grasses Declined 15%
Significant bay grass
declines in mid-Bay area overshadow gains
April, 2011 - Bay grasses in Marylandís portion of the
Chesapeake Bay and its rivers covered approximately 40,193 acres in 2010, down
from 47,294 acres in 2009. This represents 35% of Marylandís 114,000-acre bay
grass restoration goal.
2010 was the first time in three years Marylandís bay grasses decreased in
abundance. However, Marylandís 2010 bay grass coverage was the sixth highest
recorded since the Virginia Institute of Marine Science began the annual bay
grass survey in 1984.
While the Bohemia, Bush and Magothy Rivers lost significant percentages of bay
grass acreage, much of Marylandís losses occurred in the mid-Bay region (from
the Chesapeake Bay Bridge south to the Potomac River and Pocomoke Sound). Large
percentage declines were observed in the Honga River and Tar Bay area on the
Eastern Shore. Bay grasses in the Choptank, lower Patuxent, and Potomac Rivers
also declined. The dominant bay grass in this region, widgeon grass, is a boom
or bust species and almost completely disappeared from these areas in 2010.
Long-term reductions in water clarity, along with record-breaking hot summertime
temperatures, may have contributed to the bay grass declines in this region.
The significant declines in the Honga River and vicinity overshadowed the gains
in bay grass acreage observed in other areas. The upper Chesapeake Bay and its
rivers (from the Chesapeake Bay Bridge north) met 90% of the 23,400-acre
restoration goal for this region. Bay grass coverage in most upper Eastern Shore
rivers, the upper Potomac River and the Susquehanna Flats met or exceeded
restoration targets due in part to sewage treatment plant upgrades and long-term
reductions in nutrients entering the water. Bay grass beds on the Susquehanna
Flats, near Havre de Grace, have quadrupled in size since the early 1990ís and
now cover approximately 11 square miles.
On the lower Eastern Shore, eelgrass continued to rebound in Tangier and
Pocomoke Sounds and in the Manokin and Big Annemessex Rivers following the
large-scale 2005 summer die-off. Bob Orth, lead scientist for the annual aerial
surveys conducted by the Virginia Institute of Marine Science, is concerned,
however, that the record-breaking hot summertime temperatures in 2010 may
negatively affect eelgrass in 2011.
Bay grasses are important habitat in the Chesapeake Bay. They provide food and
shelter for many animals, including blue crabs, largemouth bass and canvasback
ducks. Healthy bay grass beds also protect shorelines from erosion, produce
oxygen and filter polluted water.
Because bay grasses are sensitive to even small changes in water pollution, they
serve as a key indicator of Chesapeake Bay health. Polluted runoff entering the
Bay contains nutrients that can fuel algal blooms and sediments that block
sunlight needed for bay grass growth. Further reductions in the amount of
polluted runoff and sediment entering Marylandís waterways are necessary for
continued bay grass restoration success. Working through the Chesapeake and
Coastal Bays Trust Fund, Governor Martin OíMalley is bringing together citizens,
businesses, and local, state and federal government agencies to reduce polluted
runoff. Programs to plant cover crops and restore natural filters, such as
streamside vegetation and wetlands, as well as conserve high priority lands,
restore habitats and foster smarter, greener growth and living in Maryland will
benefit bay grasses and the Bayís other natural resources.
For more information, visit:
Bay Grasses: identification, importance and status
Restoring the Chesapeake Bay: Marylandís Actions and Progress:
What can you do to help the Bay:
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