JIM LEHRER: And finally tonight: testing oysters from the Gulf Coast. That's being done by Louisiana's Department of Health and Hospitals, known as DHH.
Our story is part of our series NewsHour Connect showcasing public media reporting around the country.
Bill Rodman reports for Louisiana Public Broadcasting and the Gulf Coast Consortium of Public Broadcasters.
BILL RODMAN: While DHH had always tested oyster harvest areas for bacteria, the spill, of course, made oil an issue.
DR. JIMMY GUIDRY, Louisiana State Health Officer: What we found is that, in all the oysters we have tested, in all the seafood we have tested, that level of hydrocarbons, which would indicate the oil had reached the oysters or the seafood, was at levels that wouldn't impact human health.
BILL RODMAN: Working with NOAA and the Food and Drug Administration, the Louisiana Department of Health and Hospitals adopted a two-tiered approach for testing oysters and other seafood for hydrocarbons, the first part being sensory testing.
GARY LOPINTO, Seafood Program Manager, Louisiana Department of Health and Hospitals: All right, let me get you to open one up for me.
BILL RODMAN: Gary Lopinto is the DHH seafood program manager and a NOAA and FDA-trained and certified sensory seafood tester. He begins with a clearing of the nasal passages.
GARY LOPINTO: I need to you open me one up with. Open me one up fresh, please.
A good smell of oysters, honestly, smells like corn. It really does. The oil smell is a -- real strong, especially the crude oil.
BILL RODMAN: The purpose of the smell test is to catch any suspicious seafood at the dock or at the first processor, so that if there is a potential problem, it can be identified immediately, and the oysters can be flagged.
GARY LOPINTO: The oil from the oil spill, it is unrefined. It's natural. And it is will go into your nasal passages instantly. It is really easy to pick up.
A lighter taint is not as bad, but you will pick up some nasal burning. Once again, I'm not picking up anything.
Here you go.
And I mean these would all -- so far everything that we have done would have passed. We have not failed a load the entire summer.
BILL RODMAN: The next stage is chemical testing.
JOHN REUTHER, Eurofins Central Analytical Laboratories: And so we start with the edible oyster tissue. We grind it into a fine paste. And then we load it into these stainless steel extraction vessels here for extraction with methylene chloride.
BILL RODMAN: The oyster samples are then tested for presence of potent atmospheric pollutants known as PAHs that occur in oil. PAHs are of concern, because some compounds have been found to cause cancer, birth defects and cellular mutations.
This PAH testing is mirrored by both federal- and state-contracted independent laboratories. And the government has established levels that pose a threat to humans.
JOHN REUTHER: This is the initial extract with methylene chloride of the oyster tissue, so all of the contaminants that may be in the oyster tissue now are in this particular solution.
BILL RODMAN: Tests on this oyster solution would show up to 12 different components of PAH contaminants. So far, tests have found all the levels to be within what the FDA deems safe for human consumption.
DR. JIMMY GUIDRY: This is the most testing that has ever occurred for hydrocarbons in the history of Louisiana. So, we were convinced that, even though the oil might have reached the oyster beds, it wasn't at a level that would impact anyone's health.
BILL RODMAN: With oysters testing safe to eat, and the amount of open oyster fishing water nearly equal to what it was prior to the spill, the situation for oyster fisherman is not all you would expect.
Oystermen are recovering, but still face obstacles.
BUDDY DAISY, Buddy's Seafood, Houma, Louisiana: Oh, man, we have dropped about 75 percent. Now it's starting to come back a little bit. So, I would say we're down about 50 percent right now.
BILL RODMAN: Fifty percent?
BUDDY DAISY: Yes.
BILL RODMAN: Buddy Daisy of Buddy's Seafood in Houma has been in the oyster fishing and processing business for 50 years. He says what has hurt him the most is public perception. Nowadays, he hopes rigorous testing procedures will build confidence.
Louisiana oystermen have also faced other challenges. In the attempt to push the oil out of the estuaries, the state opened several freshwater diversions, full-throttle. Many oystermen claim this action has killed large areas of oyster beds.
While there are large areas that have had little to no impact, other oyster bed areas along the coast are reporting mortality rates as high as 80 percent. In Barataria Bay, one of Louisiana's most productive oyster fisheries, some beds on the eastern side of the bay are at 60 percent dead, although it's not clear yet if this is due to oil or low salinity.
To address the problem, the governor's office has set up a new advisory board to look into claims from oystermen that the freshwater has harmed their industry and says BP will be held accountable for any losses they may have experienced.
JIM LEHRER: Louisiana will step up testing and monitoring seafood from the Gulf. They will use $18 million from oil company BP to test 400 samples a month for the next 20 years.