Despite Rescue Effort, Bay Crabs at an Ebb
Saturday, November 17, 2007
The Chesapeake Bay's famous blue crabs -- feisty crustaceans that are both a regional symbol and a multimillion-dollar catch -- are hovering at historically low population levels, scientists say, as pollution, climate change and overfishing threaten the bay's ultimate survivor.
This fall, a committee of federal and state scientists found that the crab's population was at its second-lowest level in the past 17 years, having fallen to about one-third the population of 1993. They forecast that the current crabbing season, which ends Dec. 15 in Maryland, will produce one of the lowest harvests since 1945.
This year's numbers are particularly distressing, scientists say, because they signal that a baywide effort to save the crab begun in 2001 is falling short.
Governments promised to clean the Chesapeake's waters by 2010. But that effort is far off track, leaving "dead zones" where crabs can't breathe.
Maryland and Virginia have changed their laws to cut back the bay's crab harvest. But watermen have repeatedly been allowed to take too many of the valuable shellfish, scientists say. The watermen, meanwhile, say they're being unfairly blamed.
"Now it appears that even the hardy blue crab is approaching its breaking point," said Howard R. Ernst, a professor at the U.S. Naval Academy and a critic of government efforts to protect the Chesapeake. If the crab's population drops further, Ernst said, "what we ultimately lose is not only a resource, but a unique and irreplaceable cultural heritage."
The Chesapeake has a long roster of collapsed species, including many of its best-loved icons.
First, the sturgeon was mercilessly fished for meat and roe. Shad went next, netted and blocked off by dams. Oysters have been nearly wiped out by harvests and disease. Rockfish dropped off but then came back, the bay's best, but just about only, success story.
Through it all, the number of blue crabs held relatively steady, helped by their relatively high tolerance for dirty water and their astonishing fertility. A female crab can produce more than 6 million eggs a year, allowing the population to rebuild quickly.
But in the 1990s, the crab's population began to fall off rapidly. Since 2000, it has been at a historically low ebb.
There were about 852 million crabs in the bay in 1993, but there are now about 273 million, according to the committee of federal and state scientists, which issued a report in September. Over the past 17 years, only 2001 -- an earlier point in the current slump -- had a lower figure.
The Chesapeake crab harvest, which exceeded 100 million pounds at its peak in the 1960s, fell to 48.9 million pounds last year.