April 27, 2012
Invasion Of The Oversized Crustaceans! Asian Tiger Shrimp Invade The US
Giant cannibal shrimp are invading the coasts of America en masse -- and while it sounds like the work of a mad scientist in one of those cheesy, low-budget, black-and-white 1950s science-fiction movies, the danger (or rather, lack thereof) is all too real.
U.S. Geological Survey (USGS) and National Oceanic and Atmospheric Administration (NOAA) researchers have discovered that there were more than 10 times as many sightings of Asian tiger shrimp, which can grow to be more than a foot long and can consume their smaller relatives, off the Atlantic and Gulf of Mexico coasts in the US in 2011 than there were in 2010, CNN's Brad Lendon reported on Thursday.“We can confirm there was nearly a tenfold jump in reports of Asian tiger shrimp in 2011,” USGS Biologist Pam Fuller, the head of the agency´s Nonindigenous Aquatic Species database, said in a statement. “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.”
Researchers from the USGS and the NOAA are reportedly working with various state agencies to examine this phenomenon and discover what the massive influx of this decapod species, which is indigenous to the Indo-Pacific, Asian and Australian regions, means for native types of shrimp. The cause of the increase in sightings is unclear, Fuller said, and scientists with the two agencies are hoping to discover more about the biology of the Asian tiger shrimp and the possible impact they will have on the coastal ecosystems in the US.
"As with all non-native species, there are concerns over the potential for novel avenues of disease transmission and competition with native shrimp stocks, especially given the high growth rates and spawning rates compared with other species," the NOAA said in a press release, adding that the "non-native shrimp species may have escaped from aquaculture facilities“¦ [or] it may have been transported in ballast water from ships or possibly arrived on ocean currents from wild populations in the Caribbean or other locations."
"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 added in a separate 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."
However, while the potentially worrisome terms "giant" and "cannibal" have been used to describe the Asian tiger shrimp, they obviously do not pose any actual threat to humans. In fact, they are edible crustaceans, and according to what Fuller told Lendon, "They're supposed to be very good. But they can get very large."