RICHMOND, Va. - The Chesapeake Bay is showing encouraging signs of improvement but remains afflicted with dead zones, fish kills, and pollution, the Chesapeake Bay Foundation said Tuesday in its "State of the Bay Report."
The report notes improvements since the last report in 2008 in eight of 13 indicators, including a rebounding blue crab population and flourishing underwater grasses, a key habitat for crabs and other marine species.
Using a grading system, the bay's overall grade was a D-plus, up slightly from the 2008's D.
"The good news is the Chesapeake Bay is getting better," William C. Baker, president of the foundation, said in an interview. "The bad news is it's still a system out of balance."
The reported noted two issues specific to Pennsylvania; the entire midsection of the state, roughly straddling the Susquehanna River, is in the Chesapeake watershed.
It said Pennsylvania has led efforts to restore forested stream buffers - which serve as filters to prevent pollutants from reaching the waters. The state is responsible for 90 percent of the roughly 700 stream miles planted between 2008 and 2009, the report said.
The report also pointed to a new threat to the bay: drilling in a vast natural-gas deposit called the Marcellus Shale, which lies beneath portions of Pennsylvania, Upstate New York, Ohio, Maryland, Virginia, and West Virginia.
Among the concerns it cited are drinking-water contamination, forest fragmentation, wastewater treatment, and stress on roads, bridges, and other infrastructure.
The report was released as the Environmental Protection Agency prepares this week to establish mandatory pollution limits for six states and the District of Columbia, which make up the 64,000-square-mile watershed. The "total daily maximum loads" are aimed at reducing the bay's nitrogen and phosphorous levels by one-quarter by 2025.
"We are at a tipping point," Baker said. "If the EPA stands firm, and the states deliver on their commitments, the bay will become resilient and bountiful. At the same time, reducing pollution will create jobs and improve local economies."
In the foundation's report card, nitrogen and phosphorus levels remain well above recommended limits to restore the bay. The sources are mainly stormwater pollution, urban and agricultural runoff, and detergents.
Fed by this pollution, algae blooms suck oxygen from the bay, creating vast dead zones where no marine life exists.
The foundation measured the bay's health by using 13 indicators. They included marine life such as oysters, shad, and striped bass; buffering factors such as forests and wetlands; and water clarity, toxics, and dissolved oxygen.
Fisheries for rockfish and crabs ranked among the highest, although the report raises concerns about striped bass spawning numbers, which were below average for the third year in a row. The bay's blue crab population more than doubled since 2008, to an estimated 315 million.
Management efforts by Maryland and Virginia have been key to their recovery. The states set catch limits, tinkered with the seasons, and bought licenses back from watermen, all to ease pressure on the crab.
"The good news there is that a formula was followed," Baker said. "That formula is: Use science to set a limit. It's a terrific development."
Under the pollution category, grades were in the F and D range, although water clarity and the toxics category showed improvement since 2008.
Using another measure, the foundation puts the bay's health at 31 out of 100 - with the top measure being the unspoiled ecosystem described by Capt. John Smith during the first European exploration of the bay.