The invasive Asian Tiger Shrimp has been rapidly increasing in number in U.S. waters.
The increase has mostly been along the southeast coast and in the Gulf of Mexico. Government scientists think that as they move into the territory of native species they’ll bring disease and outcompete native species.
The shrimp can grow up to 13 inches long and weigh a fourth of a pound. Larger and heavier than the native white, brown, and pink shrimp that only grow up to 8 inches and weigh an ounce.
These shrimp are larger so they eat more and can predate other shrimp and fish. The effects of their spread could have quite a negative effect on the lucrative shrimp industry.
“That’s a big jump,” said Pam Fuller, who keeps a federal invasive species database at the U.S. Geological Survey’s Southeast Ecological Science Center in Gainesville, Florida.
Those are just the reported numbers — the actual numbers are probably vastly higher.
“I’ve had fishermen tell me they have quit bringing them in. They are seeing large numbers in their catch — multiples per night,” James A. Morris, who works at the National Oceanic and Atmospheric Administration’s Center for Coastal Fisheries and Habitat Research in Beaufort, N.C., is quoted as saying.
“(This) is the first indication that we may be undergoing a true invasion of Asian tiger shrimp,” he said.
Tiger shrimp are not currently farmed in the U.S. There was a farm in Florida that closed in 2004, though that closed without ever commercially raising a crop.
“Nobody knows what happened to their stock. But they have not been commonly caught in the area where that fish farm was,” Pam Fuller said.
Unsure of whether this is a one-time spike or an invasion, the agencies researching this are asking for the reporting of any catches, and preferably frozen specimens, that can be genetically tested to determine their origin.
There are differences in the DNA of farmed Caribbean ones, farmed west African ones, or a new resident population.
“I think it’s quite possible they’re being swept up from the Caribbean,” she said. “There are large farms there that appear to be connected directly to the ocean. Some of those were destroyed in hurricanes. We don’t know if perhaps a large bunch got loose and swept up here and became established. Nobody knows. That’s one reason we want to do the genetic work.”
Not much is known about the effects of invasive sea life on ecosystems, so it’s hard to predict the effect the shrimp could have.