BP Deepwater Horizon Oil Spill Wildlife Update: Blue Crab, Shrimp, and Oysters

South Carolina Department of Natural Resources

Blue Crab, White and Brown Shrimp
Gulf seafood has been repeatedly proclaimed safe for human consumption, according to a press release from NOAA, (the agency is working with the FDA and Gulf states to test samples from the region). But what about the organisms themselves? What’s in store for them?

We actually don’t know what kind of damage the spill has had and will have to the long-term reproductive success of species that spawn in the continental shelf waters of the Gulf of Mexico—including white and brown shrimp and blue crab—according to Richard Condrey, an associate professor in the Department of Oceanography and Coastal Sciences at Louisiana State University. “For many of these species we may never know,” he adds in an email, “because we do not have sufficient pre-spill background data.”

Basic physiology continues to suggest a grim prognosis (see last year’s post for a refresher) for a variety of animals, however. And by continuing to harvest such food as shrimp and crabs without understanding how their reproductive success has and is being affected, we further risk their sustainability, writes Condrey. “Since almost all fishery-exploited marine animals which spawn in the Gulf’s continental shelf are at least approaching overfished conditions, the additional stress of the Deepwater Horizon oil spill may constitute tipping points for many species beyond which recovery is uncertain,” he writes. “My question is, ‘Why are we doing this?’ If these are valuable resources which we enjoy eating and are a valued component of our cultural heritage, why don't we spend a few dollars to understand how they have been and are being impacted by this massive release of oil and application of dispersants?'"

Louisiana Department of Health and Hospitals

Oysters
“Last year my mantra was, ‘one day at time’; this year my mantra is ‘so far, so good,’” says John Supan, director of the Sea Grant Bivalve Hatchery on Louisiana’s Grand Isle. Oil didn’t taint his oyster hatchery on the island, though it did tarnish the beach.

Of course, if you ask an oysterman who makes his living off the mollusks, he might have a completely different story. Though little crude oil smeared reefs, according to Supan, the industry suffered from fishery closures and massive property loss. Freshwater used to divert oil from encroaching up into Louisiana marshes ended up killing about 80 percent of the state’s oysters, says Supan.

History offers a silver lining, however: In the past, freshwater inundations—from the Mississippi River overflowing, for example—have resulted, several years later, in surges in fisheries production, Supan notes. If that happens again, “then we’re back to normal.” But if there’s no rise in production, then the spill—and specifically, the effects of dispersed oil (click here to review how it could affect oysters)—will stand out as potential determining factors. “We’re watching and waiting,” says Supan, but “not with alarm. I like the word hope.”