I would ask precisely where they were caught.
If they can't tell you (highly likely), then ask them for contact info of the producer/distributer/supplier. Pretend you're a PI and just follow it up the links. Fisherman tend to fish in pretty specific areas, they have to factor in fuel cost, boundaries, seasons, etc, so eventually someone should be able to tell you where a catch is coming from. Also you may have to either compel the service staff to get this info, or more likely call a manager or info desk and they will have to get back to you when they hunt down the info. Just so's ya know, that info is probably only a few feet away on the box that the shipment arrived in, and they have to deal with this company constantly most likely so it is not an unreasonable request to make. All you really need is the name of the company, but a phone number would be even better.
Then you can comb the news real quick like to see if animals are still being found with birth defects and deformities in that area.
Unfortunately you have to take full responsibility for finding all of this information, because as I said in the other post companies tend to expend only as much effort as they need to comply with laws and safety guidelines and that usually doesn't bring very much readily accessible information to the consumer. "We have shrimp, they're wild caught, they're inspected, they don't smell funny, what more do ya' want to know?"
From whackipedia: "In late 2012 local fishermen report that crab, shrimp, and oyster fishing operations have not yet recovered from the oil spill and many fear that the Gulf seafood industry will never recover. One Mississippi shrimper who was interviewed said he used to get 8,000 pounds of shrimp in four days, but this year he got only 800 pounds a week. Mississippi's oyster reefs have been closed since the spill started. A Louisanna fisherman said the local oyster industry might do 35 per cent this year, "If we're very lucky." Dr Ed Cake, a biological oceanographer and a marine and oyster biologist, said that many of the Gulf fisheries have collapsed and "If it takes too long for them to come back, the fishing industry won't survive".[314]"
Even if the seafood is contaminant free, which is still dubious, it would be nice to let the populations rest for a year or two, since they had such intense pressure before the spill, then the spill itself, then the chemical dispersents they used to get the oil to break up and now, even more intense fishing since everyone is having to scrounge for what little shrimp/seafood seems to be available. Your call though, definitely consider wisely!
This quote, also from the 'pedia, shows that sealife was still being affected as recently as 1 year ago, there is no reason to expect that one more year was enough to work it out of the food chain, especially since there are probably still clouds of oil floating around out there in the vastness of the ocean.
"In July 2011 BP released a report[312] claiming that the economy had recovered and there was no reason to believe that anyone would suffer future losses from the spill, with the limited exception of oyster harvesters. However, Bruce Guerra, a crab fisherman in Louisiana for 25 years, said that since the BP oil spill crabbers are trapping 75 percent fewer crabs and that "crabs have been coming up dead, discolored, or riddled with holes since last year's spill". Others in the fishing industry say it could take years to fully realize the spill's effects. "The problem is right when they used the dispersants, that's when the tuna came to the Gulf to spawn," said Cheril Carey, a national sales representative for a Louisiana company specializing in yellow fin tuna. "It takes a tuna five to 15 years to mature. So although we may have fish now, we may not have them in five to 15 years."[313]"
