Shrimp Invading Louisiana Waters Give Whole New Meaning to 'Jumbo

Some shrimp do not live up to their name by being, well, not so "shrimpy" in size. A popular oxymoron is "jumbo shrimp" but the non-native crustaceans invading Louisiana waters put even this larger variety to shame.

The Times-Picayune reported Asian tiger shrimp (or prawn) becoming a growing concern in the Gulf of Mexico as the species can get larger than a foot long and weigh more than a pound, causing some to worry that it could outcompete native species.

Asian Tiger Shrimp (Photo: marsmet501/Flickr)

“We are all worried about it,” Kim Chauvin, who is a shrimp processor in Terrbonne Parish, told the Times-Picayune. “We are confused and scared and have been asking a lot of questions and not been given many answers.”

Pam Fuller with the U.S. Geological Survey’s Nonindigenous Aquatic Species Program is the lead author of a yet-to-be-published study that found within 10 years, the species will be well established in the area.

The Times-Picayune reported two theories as to how the prawns might have com into the waters:

The tiger shrimp in the Gulf likely escaped from a shrimp farm in the Caribbean Sea off the Dominican Republic during a hurricane in 2005 and then rode currents to the Gulf, several scientists have speculated. Ballast water is another possible explanation for the invasion, but scientists generally believe an escape from aquaculture is more likely simply because such farms are so widespread around the world.

Asian tiger shrimp is named for its stripes. (Photo via Wikimedia)

The Louisiana Wildlife and Fisheries website states that it believes tiger prawns being reared on the east coast in the 1980s escaped. About 1,000 were later recaptured, but in September 2006 just one male was found by a fisherman off the coast of Alabama. Reports of the prawns in that area have been increasing ever since."

LDWF first documented the occurrence of Asian tiger prawns in Louisiana in August 2007, when a single specimen was taken by a commercial shrimp fisherman in Vermilion Bay.  Prior to the 2011 fall inshore shrimp season, reported captures in Louisiana waters numbered fewer than 25 with none taken any farther westward than Vermilion Bay.  However, since the fall season began, reported captures have dramatically increased with approximately 80 new reports received.  One fisherman alone reported catching as many as 13 individuals over a three-day shrimping trip in Lake Pontchartrain.  A Dulac shrimp dock has reported fishermen capturing in excess of 100 tiger prawns following the 2011 fall season opening.  Most recently, there have also been incident reports west of Vermilion Bay.

All things considered, the tiger prawns, unlike the unwelcome invader plaguing the Great Lakes (the Asian carp), is edible. The Times-Picayune describes them as having a lighter flavor and with a firmer, chewy texture compared to "sweeter" white Gulf shrimp. To be fair, the Asian carp is technically edible but the Detroit Free Press said many won't eat the variety populating the Great Lakes as they are boney and thus difficult to prepare well.

The Associated Press reported that the inshore white shrimp season is about to start and shrimpers are being asked to send in photos of Asian tiger prawn if they find any, as researchers continue to evaluate how established the population of the invasive species is becoming.

This story has been updated since its original posting. 

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