Earth and Sky:By Jeff Swicord Sarah Creek, Mary（在线收听）

Scientists Working to Save Chesapeake Bay Oyster Population

Chespeake Bay
Chespeake Bay		    
     
The Chesapeake Bay, on the Atlantic coast, is the largest estuary in the United States. It is famous for its seafood, especially crabs and oysters. However, in the last century, the bay's oyster population has been in steady decline.

 

For hundreds of years, watermen of the Chesapeake Bay have made a living by harvesting oysters. In the last 50 years, the number of oysters has declined dramatically.  

Tommy Leggett is an Oyster Restoration and Fisheries scientist with the Chesapeake Bay Foundation, an environmental organization that works to protect the bay's resources. "Our population is down to one to three percent of historical levels. So, consequently our bay's water quality is down," Leggett said.
 
Graham Blake grew up on Sarah Creek, a tributary to the bay. His father and grandfather made a good living as watermen by harvesting, transplanting, fattening, and then re-harvesting oysters from the creek.  

Graham Blake
Graham Blake		    
     
It was an early form of oyster farming. In the 1940s and ‘50s his family could harvest 200 to 300 bushels of oysters each day. Blake says those days are long-gone.
 
"There is none of it like my father made his living, that is non-existent. Some are still trying to make a living on the water, oystering and crabbing and so forth,” Blake said. “They have got to do a lot of things. They can't just do it in one industry anymore."
 
In the late 1950s, parasites, which were introduced from foreign oysters, began to kill the Chesapeake Bay oyster population.

Graham and Tommy are now stocking the creek bed with hundreds of thousands of disease resistant young oysters. When they reach adulthood, they are transplanted to state sanctuary reefs in the bay.  
 

Chesapeake Bay program oyster reefs
Chesapeake Bay program oyster reefs		    
     
"Since 2000 we have been attempting to grow about a million oysters a year as brood stock to be placed on state sanctuary reefs to help jump start rivers,” Leggett said. “To date, we have produced about five million oysters that we have transplanted onto a number of reefs in the Virginia portion of the Chesapeake Bay."

The project seems to demonstrate that watermen and other entrepreneurs can grow oysters in the bay using aquaculture techniques.

"We have pretty well demonstrated it, and over a number of years we have had industry people come out to the site. There have been a number of people who have scaled up and are growing more oysters than we are now,” Leggett said. “Oyster farming in the bay is just getting ready to take off."
 
According to Leggett, the number of commercial operations growing oysters on the bay will dramatically increase in the next several years. His primary goal is to restore the natural oyster population to what it once was, but it is a goal he says may not happen in his lifetime.

"We are just learning some of the pitfalls and the roadblocks that we are going to encounter. We try and learn from our mistakes and change the way we do things,” he said. “It will happen in time. It's not going to happen in the short term."

  原文地址：http://www.tingroom.com/lesson/EandS/41483.html