Pauky
07-25-2004, 02:53 PM
Here's an issue related to the health of the Bay.
http://media.washingtonpost.com/wp-dyn/images/I10432-2004Jul23
Bye-Bye Bivalve?
Over-harvesting is endangering the Chesapeake's most famous mollusk, as well as the bay.
Sunday, July 25, 2004; Page B08
At this year's Smithsonian Folklife Festival, I wandered around the mid-Atlantic maritime exhibits in search of any report that the oysters that spawned the industry that built the boats on display are, lately, gone. I eventually found a small sheet showing recent harvest trends (from 2.5 million bushels of oysters in 1974 to 25,000 bushels in the past year). Unfortunately, there was no one around to discuss this gloomy report.
For those of us who believe that the oysters should be given a rest -- that we should stop harvesting them from the Chesapeake Bay -- the past couple of months have supplied powerful support for our argument.
First, Roger Newell of the University of Maryland's Center for Environmental Science at Horn Point found that not only do oysters improve water clarity as they feed, but they also contribute to the denitrification of the bay's water. This may sound esoteric, but removing nitrogen and phosphorus is essential for restoring the Chesapeake's water quality. Newell estimates that oysters reduce nitrogen in bay water at a rate of 0.226 kilograms per bushel per year. At the going rate for buying nutrient reduction from wastewater facilities, farms and developers, the value of a bushel's nutrient reduction services is about $5.42 a year. Consider this: The 1.56 million bushels harvested in 1986 would have supplied denitrification services worth about $8.45 million per year if the oysters had been left in the water. The 25,000 bushels harvested this past year provided only about $135,000 of denitrification services.
Second, Steve Jordan, while director of the Maryland Department of Natural Resources' Sarbanes Oxford Cooperative Laboratory on the Eastern Shore, developed a model for oyster population change under different levels of harvest pressure. His model showed that if harvests were restricted, the bay would have significantly more oysters. While this finding may appear obvious, the idea guiding oyster management in the bay has been, "If we don't harvest them, they are going to die from disease anyway." This conclusion has seemed self-evident to watermen who have watched swathes of oysters succumb to the two oyster diseases, Dermo and MSX. But Jordan's research undermines this assumption. His model predicts, on the basis of past population trends, how many oysters there would be (even with disease mortality) if harvesting was constrained. He reported that if fishing mortality had been restricted to 43 percent of stocks from 1986 to the present, harvests in the 2002-03 season would have been close to 2 million bushels, instead of the 51,000 bushels actually harvested.
In the early 1990s, when oyster harvests were threatened with the MSX pandemic and stocks began to tank, the Chesapeake Bay Foundation and a few other brave souls advocated a moratorium on oyster harvests. The reaction was so negative and uncivil that "a seat at the table" came to require eschewing harvest restrictions. In this environment, oyster restoration came to imply maintaining the commercial fishery as fully as possible.
One can assert that the oyster sanctuaries and productive reserves that public tax dollars have created during the past 16 years compensate for allowing watermen to continue to harvest oysters with ever more efficient gear. But in those same 16 years, the commercial oyster fishery has largely disappeared. When annual harvests go from 2.5 million bushels to 25,000, the collapse can only be called catastrophic.
In Maryland and Virginia, the race is on to introduce a non-native species that is resistant to our oyster diseases, and no groundswell has emerged for more rational oyster management. Maryland claims to be considering a moratorium on oyster harvests as a part of its environmental impact assessment for introducing the non-native oyster, but it already has rejected moratoriums that would have applied only to bay tributaries, on the basis that they wouldn't do any good -- the oysters are going to die anyway.
What remains to be seen is whether a de facto moratorium will be imposed on oyster harvests because no oysters are left, or whether we will seriously pursue restocking the Chesapeake with oysters -- even if this requires saying "no" to the watermen who want to harvest them. Unfortunately, Maryland's decision to reject its goal of setting aside 10 percent of oyster bottom as sanctuary, its lack of enforcement on existing sanctuaries and its aversion to harvest restrictions do not bode well for the Chesapeake Bay's most famous bivalve.
Source: Washington Post.com (http://www.washingtonpost.com/wp-dyn/articles/A10443-2004Jul23.html)
__________________
Tight Lines!
http://polaris.umuc.edu/~ewhistle/images/fisjump.gif
Pauky
http://media.washingtonpost.com/wp-dyn/images/I10432-2004Jul23
Bye-Bye Bivalve?
Over-harvesting is endangering the Chesapeake's most famous mollusk, as well as the bay.
Sunday, July 25, 2004; Page B08
At this year's Smithsonian Folklife Festival, I wandered around the mid-Atlantic maritime exhibits in search of any report that the oysters that spawned the industry that built the boats on display are, lately, gone. I eventually found a small sheet showing recent harvest trends (from 2.5 million bushels of oysters in 1974 to 25,000 bushels in the past year). Unfortunately, there was no one around to discuss this gloomy report.
For those of us who believe that the oysters should be given a rest -- that we should stop harvesting them from the Chesapeake Bay -- the past couple of months have supplied powerful support for our argument.
First, Roger Newell of the University of Maryland's Center for Environmental Science at Horn Point found that not only do oysters improve water clarity as they feed, but they also contribute to the denitrification of the bay's water. This may sound esoteric, but removing nitrogen and phosphorus is essential for restoring the Chesapeake's water quality. Newell estimates that oysters reduce nitrogen in bay water at a rate of 0.226 kilograms per bushel per year. At the going rate for buying nutrient reduction from wastewater facilities, farms and developers, the value of a bushel's nutrient reduction services is about $5.42 a year. Consider this: The 1.56 million bushels harvested in 1986 would have supplied denitrification services worth about $8.45 million per year if the oysters had been left in the water. The 25,000 bushels harvested this past year provided only about $135,000 of denitrification services.
Second, Steve Jordan, while director of the Maryland Department of Natural Resources' Sarbanes Oxford Cooperative Laboratory on the Eastern Shore, developed a model for oyster population change under different levels of harvest pressure. His model showed that if harvests were restricted, the bay would have significantly more oysters. While this finding may appear obvious, the idea guiding oyster management in the bay has been, "If we don't harvest them, they are going to die from disease anyway." This conclusion has seemed self-evident to watermen who have watched swathes of oysters succumb to the two oyster diseases, Dermo and MSX. But Jordan's research undermines this assumption. His model predicts, on the basis of past population trends, how many oysters there would be (even with disease mortality) if harvesting was constrained. He reported that if fishing mortality had been restricted to 43 percent of stocks from 1986 to the present, harvests in the 2002-03 season would have been close to 2 million bushels, instead of the 51,000 bushels actually harvested.
In the early 1990s, when oyster harvests were threatened with the MSX pandemic and stocks began to tank, the Chesapeake Bay Foundation and a few other brave souls advocated a moratorium on oyster harvests. The reaction was so negative and uncivil that "a seat at the table" came to require eschewing harvest restrictions. In this environment, oyster restoration came to imply maintaining the commercial fishery as fully as possible.
One can assert that the oyster sanctuaries and productive reserves that public tax dollars have created during the past 16 years compensate for allowing watermen to continue to harvest oysters with ever more efficient gear. But in those same 16 years, the commercial oyster fishery has largely disappeared. When annual harvests go from 2.5 million bushels to 25,000, the collapse can only be called catastrophic.
In Maryland and Virginia, the race is on to introduce a non-native species that is resistant to our oyster diseases, and no groundswell has emerged for more rational oyster management. Maryland claims to be considering a moratorium on oyster harvests as a part of its environmental impact assessment for introducing the non-native oyster, but it already has rejected moratoriums that would have applied only to bay tributaries, on the basis that they wouldn't do any good -- the oysters are going to die anyway.
What remains to be seen is whether a de facto moratorium will be imposed on oyster harvests because no oysters are left, or whether we will seriously pursue restocking the Chesapeake with oysters -- even if this requires saying "no" to the watermen who want to harvest them. Unfortunately, Maryland's decision to reject its goal of setting aside 10 percent of oyster bottom as sanctuary, its lack of enforcement on existing sanctuaries and its aversion to harvest restrictions do not bode well for the Chesapeake Bay's most famous bivalve.
Source: Washington Post.com (http://www.washingtonpost.com/wp-dyn/articles/A10443-2004Jul23.html)
__________________
Tight Lines!
http://polaris.umuc.edu/~ewhistle/images/fisjump.gif
Pauky