State standards for measuring the safety of seafood after oil spills were lowered by FDA for the Gulf of Mexico, the Press-Register in Mobile, AL reports.

The FDA measure in question for cancer-causing polycyclic aromatic hydrocarbon (PAH) allows 132 parts per billion (PPB) in shrimp and crab, and 143 PPB for oysters harvested from the Gulf in the aftermath of the April 20 explosion aboard the Deepwater Horizon oil platform.

BP_OilSpill_FisheryClosureMap_090310_1.pngAfter the tanker New Carissa ran aground on the Oregon coast and after an oil spill in California, the state benzo(a)pyrene equivalent limits were 45 PPM and 34 PPM, respectively, for shellfish.

FDA defends setting a standard about three times higher for Gulf coast shellfish than the standards used after those West coast spills.   It says during the time between those spills and the BP oil spill, EPA came out with updated cancer-risk data for PAH.

FDA said its levels were based on a 1 in 100,000 risk of developing cancer, while Oregon and California set their limits based on a 1-in-1 million risk.

The levels for these chemical tests and so-called “sniff and taste” tests have been used by state and federal authorities in re-opening waters to both commercial and recreational fishing.  

Just less than 40,000 square miles of federal waters in the Gulf and some Louisiana waters remain closed to fishing because of the oil that spilled from the floor of the Gulf for about three months.

FDA officials say testing in areas before waters were opened returned no samples with results above “levels of concern.”

More waters open to fishing does not mean the Gulf shellfish harvest is getting back to normal.  Last week, the Mississippi Department of Marine Resources took oystermen out to the reefs off Pass Christian Harbor.

They found enough empty oyster shells to cast doubt over the coming fall season. DMR dredged and pulled up catches with 80 to 90 percent dead. 

While Mississippi officials were blaming warm weather more than the BP oil spill, one industry expert challenged that view. 


BP’s Vessels-of-Opportunity crewmen reported submerged oil around the oyster reefs in early August, according to Ed Cake, a marine biologist who works with the oyster industry.

“On or before 11 August,” Cake says, “a massive kill of pelagic and demersal fishes (and blue crabs) occurred in the same area.”

He says “black water” conditions were observed over the Pass Christian oyster reefs and fishermen found dispersed oil absorbent pads lowered in the water column.  “Black water,” Cake says, “absorbs more solar energy than normal Sound water and that will elevate the water temperature.”

blue-crabs-featured.jpgCake said the “anecdotal evidence” suggests the deaths of fishes, crabs, and now oysters resulted from the hypoxic or low dissolved oxygen conditions in Mississippi Sound and the Pass Christian area during early August.

“Although state officials will attempt to place the blame on anything but BP’s oil and dispersants that BP’s VOO crews sprayed in that area, many folks will conclude that the fish, crab, and oyster kills would not have occurred in the absence of the BP oil and dispersants,” Cake adds.

Dead areas are raising questions about just how much oyster production can be expected by the Gulf States during the upcoming season.  Oyster areas in Louisiana were also damaged when fresh water was used to hold off the crude oil.  Fresh water can kill bivalve mollusks.

Gulf oysters are returning to local menus, but prices are high and supply is spotty.