Getting the tiger by its ‘tale’ DNR studies invasive shrimp threat Conditions looking better for spring shrimp crop

Joe Swails of Summerville brought in this 11-inch tiger shrimp in Charleston Harbor in 2014 while gigging for fish. It was the second tiger shrimp he harvested in a matter of days.

Tiger shrimp grow more than twice as big as native Lowcountry shrimp. And they might just eat them. That’s what wildlife biologists want to find out as this year’s harvest season gets underway.

If true, it could be one more gaff spike in the flank of the beleaguered commercial shrimping industry. Or it could be an unwanted boon. Wild-caught tigers, it turns out, are pretty tasty, with a succulence that samplers have compared to mild lobster.

One way or another, they are here. Since they began turning up by the handfuls after Hurricane Irene in 2011, the invasive Asian crustaceans have been regularly caught offshore and occasionally in the estuaries — although only in minuscule numbers compared to natives, so far.

The concern about cannibalism has been rumored among shrimpers and anglers since the invaders arrived. S.C. Department of Natural Resources biologists are taking part in a regional study to determine whether it’s true. The biologists are asking commercial and recreational shrimpers, crabbers and cast-netters for samples of adults and juveniles to inspect stomach contents.

There’s also concern about tigers carrying diseases that would deplete native stocks, and that the larger species could simply out-compete natives for food. Tigers can get so big that as few as two could be a pound of meat. And they are nothing if not aggressive.

Joe Swails of Summerville pulled in two of the monster shrimp, taking his bait as he gigged for fish in Charleston Harbor last year.

One way or another, getting answers to those questions might be a first step to figuring out what, if anything, can be done about them.

“They’re becoming more commonplace,” said Amy Fowler, DNR assistant marine scientist. But so little research has been done on the shrimp in the wild that the regional study is the first of its type.

Tiger shrimp are no stranger to the United States, where they have shown up on ice in supermarkets and fish stores for years from farms in places such as Thailand. They now are farmed in the Caribbean and South America.

Since 2006, the shrimp have been showing up all along the Southeast and Gulf coasts — not a lot, but they seem to be increasing enough to suggest the population is breeding. A likely explanation might be that they were swept to sea from Caribbean farms during hurricanes and are moving along the Gulf Stream, according to federal marine researchers.

They could also be one more “Caribbean creep” species scuttling their way north as ocean waters warm, Fowler said.

A very unlikely but eerie possibility is that they are descendants of 2,000 tiger shrimp accidentally released from a Bluffton seaside farm in 1988. Shrimpers pulled in some 300 of what apparently were those shrimp that year. But tigers then disappeared offshore for the next 18 years.

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