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Bay Grasses |
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Contributors: Laura Murray and Angie Hengst, HPL/UMCES
SAV stands for Submerged Aquatic Vegetation and is rooted vegetation that grows under water in shallow zones where light penetrates. These areas are important habitats for fish and molting crabs. They also contribute to reduction of shoreline erosion and the trapping of sediments and nutrients from overlying waters, which leads to improved water quality and clarity. Thus, restoration of SAV is a key component in improving the overall health of the Chesapeake Bay and its tributaries.
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Vallisinaria americana,Wild celery
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Potomageton perfoliatus,Redhead grass
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Zostera marina, Eel grass
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| (Above) Representative SAV from the upper, mid and lower Chesapeake Bay. |
| Historically, the Chesapeake Bay and its tributaries supported a multi-specific SAV community. A decline in SAV populations began in the 1960s and continued through the next two decades. Degrading water quality in the Chesapeake Bay has been reported as the primary cause of this decline. |
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| Above, Solomons Is., on the left with aerial view of SAV in 1950. Aerial view on right from 1979 showing diappearance of SAV. |
Specifically, the overabundance of nutrients from human activities has resulted in the degradation of water quality. |
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| (Above) HPL pond nutrient enrichment experiments show the effect of nutrient levels on water clarity thus impacting SAV growth. |
| Following this dramatic decline, SAV populations in the Chesapeake Bay have increased since the mid-1980s. The resurgence of SAV is attributed to increased water clarity and the reduction of terrestrial nutrient inputs, largely as a result of stricter regulations on shoreline development, progressive agricultural techniques and more stringent wastewater treatment regulations. Unfortunately, both the amount of grasses and the number of species remain depressed. In the mid to upper parts of the Bay, species diversity is a major component of a healthy viable ecosystem. |
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Restoration success
During the summer of 2001 and 2004, in an effort to restore native grass species and thus increase diversity, plots of Potamogeton perfoliatus (common name: redhead) were transplanted into existing beds of Ruppia maritima (common name: widgeon grass) in Broad Creek, a tributary of the Choptank River. During the 2005 ground survey the original P. perfoliatus transplants were located. In addition, new patches of P. perfoliatus in close proximity to (<300 meters) to the original plots were found. It is very exciting that not only did these transplants survive, but are doing well enough to colonize other areas. The aerial photographs show both our original transplants (represented by the red dots) and the new P. perfoliatus patches (represented by the yellow dots). The green line outlines the R. maritima bed. |
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