Crunch time ahead for Gulf oyster fisheries

[n2doc]

24 September 2010 by Sujata Gupta, Bayou La Loutre, Louisiana

WE HAVE been hurtling south through marshes for half an hour when Brad Robin kills the engine of his flat-bottomed oyster boat. Having already fallen off my stool once, I grab a metal rail. We've arrived at our first stop - the mouth of Lake Jean Louis Robin in south-eastern Louisiana, in the middle of the marshlands that border the Gulf of Mexico. Here, the Robins have bred and harvested oysters for generations.

Robin and his crew throw a net over the side and haul in the catch. Dozens of palm-sized eastern oysters, Crassostrea virginica, clatter onto a plastic tray. "Mostly boxes," says Ed Cake, a marine biologist with Gulf Environmental Associates in Ocean Springs, Mississippi. He holds one up for me to see. The shell hangs open, empty. Cake estimates that 75 per cent of the shells in the catch are boxes.

Mortality rates are normally closer to 5 per cent, but that changed in the aftermath of the Deepwater Horizon oil spill this year. How fast the industry rebounds depends on an event expected sometime in the next few weeks, and Cake and Robin are eagerly searching for early signs of it.

The event is the annual spatfall, when oyster larvae cement themselves onto old oyster shells and other material on the sea floor. After the spill, the Louisiana state authorities took an unprecedented decision designed keep the oil at bay and save the local oystermen, but which could also doom them: they maxed the flow of fresh water through the region's canals to three times usual levels.

more

http://www.newscientist.com/article/mg20727793.200-crunch-time-ahead-for-gulf-oyster-fisheries.html

[xchrom]

1. Recommend

[Generic Other]

2. Does it seem as if the conclusion is a bit optimistic?

Hope they are right.

[nc4bo]

3. So far, it certainly seems encouraging...

Early signs are promising. As we travel further towards the Gulf, only 20 per cent of the oysters come back as boxes. The freshwater inundation may even boost yields in the long run. Though each female produces from 75 to 150 million eggs, only 1 in 1000 survive. With so many empty shells now scattered on the sea floor, the larvae have more to latch onto, improving their odds. Moreover, the flush killed oyster predators as well as oysters. Boring sponges, for instance, are noticeably absent from the fresher inshore waters.

I hope so for their sakes.....but like was stated in the story: "Now all they can do is wait and hope for a longer gap between catastrophic events - a tall order in the Gulf of Mexico."

Can oysters can absorb contaminates like COREXIT, etc. and survive? I'm also concerned about people eating contaminated seafood.