RICHMOND, Va. (AP) - 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 grade of "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 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 comprise the 64,000 square-mile watershed. The TDMLs - or 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 primarily 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 such as 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.
"Our belief is a 50 would be a stable Chesapeake Bay system and a 70 would be restored," Baker said. "We very much believe that a 50 really should be achievable by 2025."
The report also pointed to a new threat to the bay: drilling in a vast natural gas deposit called Marcellus shale, which lies beneath portions of upstate New York, Pennsylvania, Ohio, Maryland, Virginia and West Virginia.
The gas is obtained through a process called hydraulic fracking, which uses water, abrasives and chemicals to drill through layers of shale for the gas. The EPA is studying the process to see what risks it poses to water supplies.
Chesapeake Bay Foundation: www.cbf.org