CHURCHVILLE, VA: The Chesapeake Bay is in eco-collapse. The once-clear waters are clouded with sediment, so the eel-grass cannot grow across the bottom for baby crabs to hide in. The oysters, which once filtered every bit of the bay’s water twice daily, have mostly succumbed to such viral diseases as MSX and Dermo.
The bay that yielded 25 million bushels of oyster per year in the 1940s has lately produced only about 200,000 bushels annually. Chesapeake seafood restaurants mostly import their crabmeat and oysters. Watermen have left for other jobs. A massive federal restoration project began in 1983, aiming to cut “over-fertilization” in the Bay by 40 percent—but regulating sewage plants and farm fertilizer has failed to make much difference.
Wasn't pollution or over harvesting, but power dredges
We hadn’t done the science. Blaming “pollution” was no adequate prescription for restoring the Bay’s health. But research has apparently now found the key. A recent massive experiment in the Great Wicomico River found that oysters on high shell reefs (16–18 inches above the bottom) are thriving. The test-bed oysters are fighting off the diseases and grow above the sediment, while oysters on the river bottom and on lower shell mounds failed again.
The Great Wicomico now has as many oysters as all the waters of Maryland—185 million. The journal Science reports “unprecedented restoration of a native oyster population.”
It wasn’t pollution. It was the gradual permission for power dredges in the Bay, which traditionally had permitted only sail-powered dredges. The power dredges tore at the shell piles that were vital to the health of the oysters and the baywater they filtered. Viruses attacked successfully because the oysters were no longer growing high up at optimum-flow depths. After the oysters failed, the water then clouded, hampering the eelgrass and the baby crabs.
The eco-activists’ cries of “overharvesting” and “pollution” led us in the wrong direction. The money spent on the bay’s restoration up until now has been largely wasted. But now the future of the bay looks bright: give the oysters high starter-reefs, protect them from harvest until they reach sustaining numbers, and guard the shell reefs against power dredging.
Obviously, we need a better way to harvest oysters—which will provide major benefits to oyster populations in Europe, Australia and affluent regions around the world where oysters and their water-filtering have been 90 percent lost.
It seems so simple suddenly! Since we did the research.
The environmental movement hasn’t been much help at fixing things:
- Farmers, not environmentalists, invented the herbicide-based no-till farming that cuts soil erosion by up to 95 percent.
- The behavior of the ozone hole in the Arctic hasn’t changed since we banned the supposedly-evil CFCs.
- School children found frogs with too many legs or too few, and the activists blamed it on pesticide runoff. Science has shown the deformities were caused by natural parasites burrowing into the leg joints of the tadpoles—and dragonfly larvae eating them off.
Conservation is a wonderful thing, but it is science that gives us the capacity to achieve it.
Resource:
D.M. Schulte et al; “Unprecedented Restoration of a Native Oyster Population, Science, vol. 325, August 28, 2009; pp. 1124–1127.
