Report Details Impact Of Bad Water on Crab Population

December 30th, 2008 by WY Daily Staff

Report Details Impact Of Bad Water on Crab Population

VIMS Research Cited in CBF Report

(ANNAPOLIS, MD) — Pollution has been a major factor in the decline of the Chesapeake Bay’s blue crab population, according to a new report from the Chesapeake Bay Foundation. The report, the most comprehensive assessment of pollution’s impact on this Chesapeake Bay icon, was developed from interviews with 12 leading crab researchers and water quality experts, as well as federal government data and scientific papers. The Bay’s blue crab population has plummeted from 791 million in 1990 to 260 million in 2007.
Key findings include that dead zones kill an estimated 75,000 tons of bottom-dwelling clams and worms each year, enough to feed 60 million crabs annually. In addition, algal blooms caused by nitrogen and phosphorus pollution have damaged underwater grass beds, key crab habitat. More than half the eelgrass beds in the lower Bay have died since the early 1970s.
“The federal Commerce Department has declared the crab fishery an economic disaster. It is now well past time for the federal Environmental Protection Agency to do its job. The agency should be honest by admitting they have failed. They should bring forward a plan to enforce the Clean Water Act and reduce Bay pollution to levels that will restore water quality,” said CBF President William C. Baker. “It’s not just the crabs that are suffering; people are. Jobs have been lost and the economy has been damaged.”
According to the Virginia Institute of Marine Science, jobs relating to crabbing in Maryland and Virginia have fallen 40 percent between 1998 and 2006 (the most recent year for which economic data is available). Looking more broadly at the impact on restaurants, crab processors and wholesalers, VIMS estimates the economic cost to Maryland and Virginia about $640 million over the same time period.
Researchers also say that dead zones concentrate crabs in shallower areas near shore, making them more vulnerable to harvesting and cannibalism. In addition, the declining habitat reduces the Bay’s carrying capacity, the number of crabs that can be produced and maintained. As a result, fishing must be managed much more carefully.
“Past fisheries management decisions in Maryland and Virginia share some of the blame for the falling population,” said CBF Senior Fisheries Scientist Bill Goldsborough. “For the last 10 years, management policies have allowed more crabs to be harvested than science dictates. However, even with the current better management, we still need to reduce pollution if we want to see a healthy, robust crab population.”
In the final section of CBF’s Bad Waters 2008, the group noted that, “a court threw out recent federal clean air rules” (page 15). This was an accurate statement at the time of writing. Last week, the U.S. Court of Appeals for the District of Columbia allowed the rules to stand until they can be rewritten by EPA or the underlying law can be changed by Congress.
The report is available online.