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Fresh water killing off Gulf oysters

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#1 Rail Paul

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Posted 20 July 2010 - 11:52 AM

The WSJ has an article about an unintended consequence of the Gulf oil spill. As Louisiana wetlands managers open spillways to allow more fresh river water into the salty oyster zones, more oysters are dying. In some cases, 60% of the population has been killed.

In normal situations, the river water is channeled away from the marshlands. In an effort to prevent oil from entering the growing areas, managers opened the river channels, increasing the flow of fresh water to the beds, pushing back the tidal salty, oily Gulf waters. Even in areas where oil hadn't been detected.

The immediate result is a sharp drop in harvestable oysters, a rise in wholesale prices for those that remain, and lots of finger pointing.

Over the century that Mr. Collins's family has been growing and harvesting oysters in Snail Bay, near Barataria Bay, innumerable hurricanes have sunk some of his family's boats and ripped apart their houses, he said. But no natural storm ever decimated the Collins Oyster Co.'s about 2,000 acres of oyster beds as much as the river water unleashed in recent weeks by state officials appears to have done. Mr. Collins surveyed some of his family's oyster grounds on Friday and found cluster after cluster of empty shells flapping apart—meaning the animal inside was dead.

Wholesale oyster prices at P&J Oyster Co. have risen about 20% since the oil spill started and they are likely to rise further, said Al Sunseri, president of the longtime New Orleans oyster processor and distributor. "It's Economics 101," he said, citing the laws of supply and demand.

Patrick Banks, the biologist at the Louisiana Department of Wildlife and Fisheries who oversees the state's oyster fishery, said his office recently tested the waters in one of the most productive parts of Barataria Bay and found that roughly 60% of the oysters had died. In other areas of the bay, he said, the mortality level was around 10%.One die-off a few weeks ago was so extensive that visible masses of oyster meat were floating on the bay's surface. "It looked like a fish kill," said Mr. Banks, explaining the kill occurred "so fast and was so large that the predators that normally would eat up the oyster meat just couldn't keep up."

He blamed the deaths on the combination of summer heat and the salinity drop triggered by the opening of the fresh-water channels, known as "diversions"—a decision made by officials in another state office who were attempting environmental triage. "The state took the measure to try to protect the interior marshes," Mr. Banks said. "These are just some of the effects of that."

A spokesman for the Louisiana Coastal Protection and Restoration Authority, the state entity that oversaw both the berm construction and the river-water release, said it is "obvious" that the state's fresh-water releases reduced salinity in the oyster beds.

But he said those intentional releases were just one of several factors contributing to the salinity drop; others included rain and the natural flow of the river. Linking a specific number of oyster deaths to the fresh-water releases will be difficult, he said.

The authority's chairman, Garret Graves, said in a written statement that state officials "are currently evaluating all of the adverse effects associated with the oil spill and that BP PLC "is expected to pay" for all spill-related damage.

“It must be remembered that there is nothing more difficult to plan, more doubtful of success, nor more dangerous to manage than a new system. For the initiator has the enmity of all who would profit by the preservation of the old institution and merely lukewarm defenders in those who gain by the new ones. ”
Niccolò Machiavelli

#2 Ron Johnson

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Posted 20 July 2010 - 12:04 PM

Letting in the fresh water kills one season of oysters. Letting in the oil destroys the habitat for decades, killing many seasons of oysters.