‘Cannibal’ Shrimp Numbers in U.S. Waters Continue to Grow

We’ve heard stories of lakes in America coming under attack from all sorts of invasive marine life, and now it looks like our oceans are under attack, too–from terrifying cannibal shrimp.

Okay, so maybe cannibal shrimp aren’t terrifying, but they are becoming a problem. Asian tiger shrimp, as this 13-inch species of shrimp-eating shrimp is more commonly called, are native to the waters around Asia and Australia, but over the past few years a growing number of cannibal shrimp have turned up in the waters off American shores.

The cannibal shrimp have been spotted along the east coast and the gulf coast for several years, and according to reports their numbers are growing significantly; according to a new report from the USGS, the Asian tiger shrimp population in America’s waters has increased 10 times between 2010 and 2011.

“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.”

While it’s not uncommon for people to dine on the cannibal shrimp–by some accounts, tiger shrimp make for good eating–some biologists are concerned about their peculiar eating habits. And while tiger shrimp are generally considered to be safe to eat, USGS biologist Pam Fuller points out that they are “very” disease-prone.

The cannibal shrimp don’t present any immediate concern, but the USGS says it will continue researching what, exactly, the cannibal shrimp are eating in American waters, and how they got there in the first place.

“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.”