Giant cannibal shrimp more than a FOOT long invade waters off Gulf Coast
- Tiger shrimp are native to Asia though there have been more sightings in recent years
- Prawns are known to grow to the size of lobsters and eat smaller shrimp
A big increase in reports of Asian tiger shrimp along the U.S. Southeast coast and in the Gulf of Mexico has federal biologists worried the species is encroaching on native species’ territory.
The shrimp are known to eat their smaller cousins, and sightings of the massive crustaceans have gone up tenfold in the last year, biologists say.
The black-and-white-striped shrimp can grow 13 inches long and weigh a quarter-pound, compared to eight inches and a bit over an ounce for domestic white, brown and pink shrimp.
Scientists fear the tigers will bring disease and competition for native shrimp. Both, however, can be eaten by humans.
‘They’re supposed to be very good,’ Pam Fuller, a biologist with the U.S. Geological Survey told CNN. ‘But they can get very large, sorta like lobsters.’
The last U.S. tiger shrimp farm closed in Florida in 2004, without ever raising a successful crop, according to a USGS fact sheet about the species.
Reports of tiger shrimp in U.S. waters rose from a few dozen a year – 21 in 2008, 47 in 2009 and 32 in 2010 – to 331 last year, from North Carolina to Texas.
‘That’s a big jump,’ Ms Fuller told the Associated Press.
Massive: Some scientists have compared to tiger prawns to be the size of small lobsters
And those are just the numbers reported to the government.
‘I’ve had fishermen tell me they have quit bringing them in.
‘They are seeing large numbers in their catch – multiples per night,’ said Morris, who works at the National Oceanic and Atmospheric Administration’s Centre for Coastal Fisheries and Habitat Research in Beaufort, North Carolina.
The increase ‘is the first indication that we may be undergoing a true invasion of Asian tiger shrimp,’ he said.
‘Nobody knows what happened to their stock. But they have not been commonly caught in the area where that fish farm was,’ she said.
To find out whether last year’s increase was a one-time spike or the vanguard of an invasion, the agencies are asking people to keep a wide eye for tiger shrimp, to report where and when they find them, and bring back frozen tiger shrimp to help learn where they’re coming from.
AND FROM CNN:
Scientists: Giant cannibal shrimp invasion growing
An invasion of giant cannibal shrimp into America’s coastal waters appears to be getting worse.
Researchers from the U.S. Geological Survey and the National Oceanic and Atmospheric Administration reported Thursday that sightings of the massive Asian tiger shrimp, which can eat their smaller cousins, were 10 times higher in 2011 than in 2010.
“And they are probably even more prevalent than reports suggest, because the more fisherman and other locals become accustomed to seeing them, the less likely they are to report them,” said Pam Fuller, a USGS biologist.
The shrimp, which can grow to 13 inches long, are native to Asian and Australian waters and have been reported in coastal waters from North Carolina to Texas.
They can be consumed by humans.
“They’re supposed to be very good. But they can get very large, sorta like lobsters,” Fuller said.
While they may make good eatin’ for people, it’s the eating the giant shrimp do themselves that worries scientists.
“Are they competing with or preying on native shrimp,” Fuller asked. “It’s also very disease-prone.”
To try to get those answers, government scientists are launching a special research project on the creatures.
“The Asian tiger shrimp represents yet another potential marine invader capable of altering fragile marine ecosystems,” NOAA marine ecologist James Morris said in a statement. “Our efforts will include assessments of the biology and ecology of this non-native species and attempts to predict impacts to economically and ecologically important species of the Atlantic and Gulf of Mexico.”
Scientists are uncertain how many of the giant shrimp are in U.S. waters.
In 1998, about 2,000 of the creatures were accidentally released from an aquaculture facility in South Carolina. Three hundred of those were recovered from waters off South Carolina, Georgia and Florida within three months.
Farming of the giant shrimp ended in the United States, but they were caught again off Alabama, North Carolina, Louisiana and Florida.
Five were caught off Texas last year, according to Tony Reisinger, country extension agent for the Texas Sea Grant Extension Service.
Scientists don’t know if there is a breeding population in U.S. waters. Tiger shrimp females can lay 50,000 to a million eggs, which hatch within 24 hours. Or the shrimp may be carried here by currents or in ballast tanks of marine vessels.
The latest study will look at the DNA of collected specimens.
“We’re going to start by searching for subtle differences in the DNA of Asian tiger shrimp found here – outside their native range – to see if we can learn more about how they got here,” USGS geneticist Margaret Hunter said in a statement. “If we find differences, the next step will be to fine-tune the analysis to determine whether they are breeding here, have multiple populations, or are carried in from outside areas.”