There has been a surge in catches in North Carolina and the rest of the Southeast of the Asian tiger shrimp, a Pacific and Indian Ocean species that can grow more than a foot long and weigh nearly a pound.
Along the Gulf Coast and South Atlantic, catches increased from 32 in 2010 to 331 last year, according to the U.S. Geological Survey. "We've been monitoring it for some time, and in 2011 we saw several major increases in the Southeast," said James Morris, an ecologist who studies invasive species for the National Oceanic and Atmospheric Administration's National Centers for Coastal Ocean Science in Beaufort, NC. "When you see a sharp jump like that, it's a first alarm that we may be seeing an invasion."
North Carolina's coast is the northern limit of the tiger shrimp's invasive range. They can't live in water that's cooler than about 55 degrees, Morris said. The first of the oversized crustaceans caught there was landed in 2006 in the Pamlico Sound, according to Geological Survey records. Since then, only a handful have been found. But the total jumped from two reported in 2010 to 19 in 2011, adding to the regional spike.The jump around the Southeast has triggered a wave of alarmed
news accounts that sometimes refer to the shrimp as not just giants, but cannibal giants.
Yes, tiger shrimp eat smaller shrimp. But so do native shrimp and most species of fish, Morris said. "That's fine, though, because if calling them cannibals puts more attention on the problem, that's a good thing," he said. "The basic point is that invasive species are bad. We may be on the verge of seeing a big
increase in this species in the Southeast and Gulf Coast, and we don't know what the long-term impacts of that would be." So what would happen?
Like its smaller cousins, tiger shrimp is a bottom feeder, nibbling detritus, small plants and animals. The giant ones, though, can eat larger creatures and tend to be more carnivorous than native shrimp. Their extraordinary size is one of the biggest wild cards in trying to predict its effect. There is nothing else quite like it in the area. It's possible that if populations zoom, the tiger shrimp could turn out to be a better competitor for food and would edge native shrimp and fish species. it could become dominant in the manner of invasive organisms such as kudzu and zebra mussels.
But as reporter Jay Price noted, "they have an established culinary reputation: They are popular in Asia and elsewhere in the world, and often are sold under the name Giant Tiger Prawns. They can be a little tougher than properly cooked native North Carolina shrimp, but they undeniably have a lot more meat."
