Survey consistent with Bay-wide results; Susquehanna Flats beds remain healthy
ANNAPOLIS — Underwater bay grass acreage throughout much of Maryland’s portion of the Chesapeake Bay suffered a setback in 2006 as a result of high rainfalls in many parts of the Bay watershed. Total acreage in Maryland dropped to 32,586 acres in 2006, down nearly 9,734 acres from 42,320 acres in 2005. The high flows of late June 2006 sent large amounts of sediments and nutrients into the Bay, clouding the water and reducing the amount of light available for bay grasses.
Bay grasses, or submerged aquatic vegetation (SAV), are a critical resource that provide food and habitat for a wide range of Bay species, including crabs, fish and waterfowl. Bay grasses also protect shorelines from erosion, remove nutrients from the water, and trap sediments that cloud bay waters. Sources of these excess nutrients include natural sources, sewage treatment plants, industries, automobiles, and runoff from agriculture and urban areas. Sources of excess sediments include improper agriculture techniques, impervious surfaces, and erosion.
“Our monitoring results remind us that more needs to be done to reduce nutrients and sediment inputs into the Chesapeake Bay” said Secretary John R. Griffin of the Maryland Department of Natural Resources (DNR). “We are hopeful that the ongoing nutrient reduction efforts and implementation of the Tributary Strategies reverse this trend and help accelerate the progress made towards our restoration goals over the last decade.”
Currently Maryland has achieved about 30 percent of its 2010 bay grass restoration goal of 110,000 acres. Since Maryland began monitoring, bay grass acreage has more than doubled from about 14,000 acres in 1984. However, the current rate of increase will not be sufficient to achieve Maryland’s bay grass restoration goal. Given these goals and the current bay grass status, losses such as those in 2006 are a cause for concern.
“These annual fluctuations in bay grass acreage are to be expected, and our extensive field observations for 2006 revealed healthy populations of SAV in many areas,” said Mike Naylor, director of SAV restoration and education for DNR and chair of the Chesapeake Bay Program SAV workgroup. “We remain encouraged by the trend of the last decade and have every reason to believe the Upper Bay will continue to improve.”
The losses occurred throughout Maryland’s tributaries, with the largest declines in the upper Chesapeake Bay, Sassafras, Bush, Gunpowder, Honga, Lower Choptank and Lower Potomac River. These areas accounted for nearly 85 percent of the Maryland declines. Decreases in water clarity in many of these areas were identified by DNR’s Water and Habitat Quality Monitoring Program. Some losses were also noted in Tangier Sound, home to most of Maryland’s eelgrass population. Spring surveys in 2006 documented several sparse eelgrass beds, possibly the continued result of the 2005 die-back from elevated summer water temperatures.
Despite the overall reduction in bay grass coverage in 2006, the Susquehanna Flats and the Northeast River recorded their highest levels since the survey began in 1984. Slight increases were also noted in the upper Potomac River, Mattawoman Creek, Elk River and Fishing Bay. Numerous Maryland areas have been showing major bay grass increases since the mid- 1990s including the Susquehanna Flats, Bush, Gunpowder, Magothy, Severn, Bohemia and Sassafras Rivers, Mattawoman and Piscataway Creeks and the Lower Potomac River.
Underwater bay grasses are also present throughout Maryland’s portion of Coastal Bays. Also surveyed annually, the results from the Coastal Bays will be available in several weeks.
Source: Maryland Department of Natural Resources (DNR)