'Bad water' suffocates Va. reefs
Oysters are among the creatures dying from oxygen-less waters
BY LAWRENCE LATANE III
TIMES-DISPATCH STAFF WRITER Sep 13, 2005
The same time pollution was creating a near-record "dead zone" in the Chesapeake Bay this summer, pockets of oxygen-less water were spreading invisibly toward shore to smother sea life.
The Great Wicomico River, for example, is just one of many bay tributaries wrinkling the Virginia coastline with scenic inlets of sun-speckled blue water that is busy with stalking herons, splashing fish and circling gulls.
But when Jim Wesson, who manages oysters for the Virginia Marine Resources Commission, pulled on scuba gear and slipped beneath the waves to inspect an underwater oyster reef early last month, the sight was hardly sublime.
"The bottom was black," he said. Oysters were dead. Even barnacles and algae were dead.
Of the three reefs that Virginia, the Chesapeake Bay Foundation, Virginia Institute of Marine Science and the Army Corps of Engineers built in the Northern Neck river last year, two were suffocating under a blanket of bad water, Wesson said.
Water containing less than 2 milligrams per liter of oxygen is called anoxic by scientists, and it can support few living creatures for long.
"It's amazing how much is around," Wesson said, citing other instances in the Rappahannock, the Piankatank, the York rivers and elsewhere. "You find it in every single river," he said. "It varies with each river, but it's pervasive."
And, to Wesson's annoyance, "it seems like it's something that's off the radar screen with people's concerns because everything looks good on top."
Twenty years into a regional effort to control bay pollution, nutrients from sewage-treatment plants, farms, lawns and city streets continue to fuel excess algae growth. That growth ultimately wrings life-giving oxygen from the bay.
Fish and crabs usually avoid disaster by swimming away from anoxic zones. Oysters, clams, marine worms and many other creatures lack that option.
The situation only complicates the plight of the bay's oysters. Once a source of wealth for watermen and packers along the estuary, the bay's oyster population collapsed with the spread of oyster parasites in the mid-1980s.
Scientists estimate that oysters now number only 2 percent of their former abundance. Virginia, Maryland and the federal government have vowed to increase oyster populations tenfold. State officials say oysters are so scarce in proportion to suitable habitat that anoxic water is of little threat to the oyster-recovery effort.
"But, maybe, once we restore oysters to two or three times more [current numbers] we might start running into problems," said Rick Hoffman, who monitors the bay's condition for the Virginia Department of Environmental Quality.
Large algae blooms have appeared in the lower York and James rivers in recent weeks, Hoffman said. A Chesapeake Bay Foundation photographer took aerial photographs of the York River bloom at the Coleman Bridge on U.S. 17 on Friday to show the extent of bad water. The bloom stretched across the river from Gloucester Point to Yorktown, discoloring water on both sides of the bridge.
He said the state and the bay region are "making headway" at reducing the nutrients, nitrogen and phosphorous that pour off the land after rains and flush into streams from sewage-treatment plants and cause pollution.
"But, we've got a long way to go," he added.
A commission headed by former Gov. Gerald L. Baliles last year recommended the creation of a $15 billion fund to improve sewage treatment and encourage farming methods that protect water quality.
"It all depends on the rate of implementation [of the improvements], the money available and the political will," Hoffman said.
The Environmental Protection Agency's Chesapeake Bay Program announced that 10 percent of the water in the mainstem of the bay was anoxic during a survey from Aug. 8 through Aug. 11. Forty-one percent of the same deep-channel area was found to contain less than 5 milligrams per liter of oxygen, which is insufficient for striped bass and shad. The area was the fourth or fifth largest the survey has detected since it began in 1985.
Results from a follow-up cruise later in the month showed improvements once the August heat wave broke and lower temperatures enhanced water's oxygen-carrying capacity. The portion of the bay's mainstem with less than 5 milligrams per liter of oxygen slipped to 28 percent.
The survey does not examine the dozens of rivers that feed the bay, or the estuary's shoreline. Those areas are shallow enough that the water is typically well-supplied with oxygen by winds and waves. Sometimes, though, pools of bad water burp out of the bay's depths and invade the shallows if driven by tide or wind.
The bay's depths are more susceptible to oxygen problems than its shallows. At depths 20 feet or lower, water tends to stratify in bands according to temperature that discourage mixing with the surface where oxygen levels are high. If those deep strata are full of nutrients, the result is an explosion of algae that rapidly deplete oxygen when they die and decompose.
Brian Rheinhart, who is managing Chesapeake Bay oyster-restoration efforts by the U.S. Army Corps of Engineers, said oxygen levels in the Great Wicomico River this summer below 12 feet deep have been low.
The corps expects to place 15 million oysters on the three reefs it helped build in the river by early- to mid-December.
Because of the oxygen problems that occurred early last month, Rheinhart has instructed the hatchery not to drop any oysters into depths greater than 10 feet.
It's a precaution that some private oyster planters have already taken in the Coan and Yeocomico Rivers on the Northern Neck.
"We call it adaptive management," Rheinhart said.
Oysters are among the creatures dying from oxygen-less waters
BY LAWRENCE LATANE III
TIMES-DISPATCH STAFF WRITER Sep 13, 2005
The same time pollution was creating a near-record "dead zone" in the Chesapeake Bay this summer, pockets of oxygen-less water were spreading invisibly toward shore to smother sea life.
The Great Wicomico River, for example, is just one of many bay tributaries wrinkling the Virginia coastline with scenic inlets of sun-speckled blue water that is busy with stalking herons, splashing fish and circling gulls.
But when Jim Wesson, who manages oysters for the Virginia Marine Resources Commission, pulled on scuba gear and slipped beneath the waves to inspect an underwater oyster reef early last month, the sight was hardly sublime.
"The bottom was black," he said. Oysters were dead. Even barnacles and algae were dead.
Of the three reefs that Virginia, the Chesapeake Bay Foundation, Virginia Institute of Marine Science and the Army Corps of Engineers built in the Northern Neck river last year, two were suffocating under a blanket of bad water, Wesson said.
Water containing less than 2 milligrams per liter of oxygen is called anoxic by scientists, and it can support few living creatures for long.
"It's amazing how much is around," Wesson said, citing other instances in the Rappahannock, the Piankatank, the York rivers and elsewhere. "You find it in every single river," he said. "It varies with each river, but it's pervasive."
And, to Wesson's annoyance, "it seems like it's something that's off the radar screen with people's concerns because everything looks good on top."
Twenty years into a regional effort to control bay pollution, nutrients from sewage-treatment plants, farms, lawns and city streets continue to fuel excess algae growth. That growth ultimately wrings life-giving oxygen from the bay.
Fish and crabs usually avoid disaster by swimming away from anoxic zones. Oysters, clams, marine worms and many other creatures lack that option.
The situation only complicates the plight of the bay's oysters. Once a source of wealth for watermen and packers along the estuary, the bay's oyster population collapsed with the spread of oyster parasites in the mid-1980s.
Scientists estimate that oysters now number only 2 percent of their former abundance. Virginia, Maryland and the federal government have vowed to increase oyster populations tenfold. State officials say oysters are so scarce in proportion to suitable habitat that anoxic water is of little threat to the oyster-recovery effort.
"But, maybe, once we restore oysters to two or three times more [current numbers] we might start running into problems," said Rick Hoffman, who monitors the bay's condition for the Virginia Department of Environmental Quality.
Large algae blooms have appeared in the lower York and James rivers in recent weeks, Hoffman said. A Chesapeake Bay Foundation photographer took aerial photographs of the York River bloom at the Coleman Bridge on U.S. 17 on Friday to show the extent of bad water. The bloom stretched across the river from Gloucester Point to Yorktown, discoloring water on both sides of the bridge.
He said the state and the bay region are "making headway" at reducing the nutrients, nitrogen and phosphorous that pour off the land after rains and flush into streams from sewage-treatment plants and cause pollution.
"But, we've got a long way to go," he added.
A commission headed by former Gov. Gerald L. Baliles last year recommended the creation of a $15 billion fund to improve sewage treatment and encourage farming methods that protect water quality.
"It all depends on the rate of implementation [of the improvements], the money available and the political will," Hoffman said.
The Environmental Protection Agency's Chesapeake Bay Program announced that 10 percent of the water in the mainstem of the bay was anoxic during a survey from Aug. 8 through Aug. 11. Forty-one percent of the same deep-channel area was found to contain less than 5 milligrams per liter of oxygen, which is insufficient for striped bass and shad. The area was the fourth or fifth largest the survey has detected since it began in 1985.
Results from a follow-up cruise later in the month showed improvements once the August heat wave broke and lower temperatures enhanced water's oxygen-carrying capacity. The portion of the bay's mainstem with less than 5 milligrams per liter of oxygen slipped to 28 percent.
The survey does not examine the dozens of rivers that feed the bay, or the estuary's shoreline. Those areas are shallow enough that the water is typically well-supplied with oxygen by winds and waves. Sometimes, though, pools of bad water burp out of the bay's depths and invade the shallows if driven by tide or wind.
The bay's depths are more susceptible to oxygen problems than its shallows. At depths 20 feet or lower, water tends to stratify in bands according to temperature that discourage mixing with the surface where oxygen levels are high. If those deep strata are full of nutrients, the result is an explosion of algae that rapidly deplete oxygen when they die and decompose.
Brian Rheinhart, who is managing Chesapeake Bay oyster-restoration efforts by the U.S. Army Corps of Engineers, said oxygen levels in the Great Wicomico River this summer below 12 feet deep have been low.
The corps expects to place 15 million oysters on the three reefs it helped build in the river by early- to mid-December.
Because of the oxygen problems that occurred early last month, Rheinhart has instructed the hatchery not to drop any oysters into depths greater than 10 feet.
It's a precaution that some private oyster planters have already taken in the Coan and Yeocomico Rivers on the Northern Neck.
"We call it adaptive management," Rheinhart said.
