BEAUFORT — An invasive species has had a sighting explosion in North Carolina and other southern states’ coastal waters.
Dr. James Morris, ecologist with the National Oceanic and Atmospheric Administration lab on Pivers Island, said hundreds of Asian tiger shrimp (also known as black tiger shrimp) were sighted this summer throughout the southeast United States and the Gulf of Mexico. This non-native species has been under observation by NOAA, the U.S. Geological Survey, the N.C. Division of Marine Fisheries, the South Carolina Department of Marine Resources and other state agencies.
“We are unsure at this point if we’re dealing with a self-reproducing population in the Atlantic or if the sightings are the result of continued releases (from aquaculture farms),” Dr. Morris said.
A number of sightings have been made in North Carolina; specimens have been collected, as well. At the Beaufort lab, Dr. Morris took several shrimp out of a freezer and laid them out on a tray. Each shrimp was easily longer from head to tail than his entire hand.
“We’ve been monitoring them for years,” Dr. Morris said. “It’s one of many non-native species we’re finding in Atlantic waters. This one has been in background levels, but this year, fishermen were reporting them in the hundreds.”
The USGS has a real-time database tracking the reported sightings and collections on tiger shrimp. In North Carolina, there were 41 recorded sightings and/or collections this year alone, 16 of them in Carteret County.
Dr. Morris said the DMF tells them there are a lot more sightings and collections than that.
“Some fishermen take them home,” he said. “We’ve been collecting data (nationally) since 1998. Half the collections we have in North Carolina were from this year alone.”
Asian tiger shrimp are a species of shrimp capable of growing upwards of 13 inches long. The shrimp can weigh over a quarter of a pound each. Dr. Morris said the shrimp are carnivorous.
“As adults, they’re capable of eating small fish and other shrimps,” he said. “We’re concerned that they may affect native shrimp species by direct competition, disease transmission or other unforeseen impacts.”
Asian tiger shrimp are native to the Indo-West Pacific. In their native area, they’re a common aquaculture species, with worldwide production in 2009 coming in at 770,000 tons valued at over $3.5 billion. Dr. Morris said they’re not sure how the shrimp came to North Carolina or the Atlantic coast; he’s not aware of any active tiger shrimp farms in the U.S. at this time.
“It’s speculated that the specimens we’re collecting in the U.S. waters were released accidentally from aquaculture farms somewhere in the Caribbean,” he said. “In 1988, there was an accidental release from a South Carolina mariculture facility, but I wouldn’t blame it (the introduction of the shrimp) on that. This shrimp has been cultured in the Caribbean for years.”
Dr. Morris and his colleagues are working on an integrated assessment of the tiger shrimp population in the Atlantic, as well as their next steps to address the invasive species. He said they expect to have the assessment and plan done in 2012.
The DMF is asking fishermen who catch tiger shrimp to freeze it, record the date and location the shrimp was taken, and to contact Trish Murphey, DMF biological supervisor for the central district, by phone at (800) 682-2632 or by email at Trish.Murphey@ncmail.net.