The Louisiana Department of Wildlife and Fisheries is aware of and constantly monitoring the appearance of Asian tiger prawns, a non-native species, in Louisiana waters. LDWF officials are asking local shrimp harvesters to report catches of tiger prawns to the Department.
While there is little known at this time about the impacts of tiger prawns on indigenous Louisiana shrimp, these reports are key in helping LDWF biologists monitor the distribution and relative abundance of these prawns and in determining the possible presence of spawning populations.
To report catches of Asian tiger prawns please contact Robert Bourgeois at rbourgeois@wlf.la.gov or (225) 765-0765 or Martin Bourgeois at mbourgeois@wlf.la.gov or (985) 594-4130, with the date, location and size of capture. Photographs are encouraged.
Tiger prawns are easily identifiable by their large size, dark body color and white banding found along the head and between segments of the tail. Occasionally, red or yellow stripes are present as well. LDWF officials ask that harvesters retain the tiger prawns by freezing and contact the biologist listed above.
History of incidence in Gulf of Mexico
It is unknown when and how tiger prawns were first introduced into the Gulf of Mexico. In 1988, a portion of a population of reared tiger prawns escaped from a facility on the east coast. Approximately 1,000 adults were later recaptured as far south as Cape Canaveral, Florida. In September 2006, a single adult male was captured by a commercial shrimp fisherman in Mississippi Sound near Dauphin Island, Alabama and reports from Alabama and Mississippi 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.
About the species
Asian tiger prawns are native to the Indo-Pacific rim and are both harvested in the wild and extensively farmed in a number of countries.
Tiger prawns belong to the same family (Penaeidae) as our native brown, white and pink shrimp but are non-indigenous to our waters. The life history of tiger prawns is also similar to that of brown and white shrimp with spawning and mating occurring in nearshore oceanic waters. One notable difference in tiger prawns and Louisiana shrimp is size as the research suggests tiger prawns may reach a maximum length of 14 inches and weigh as much as 23 ounces.
At this time, there is no evidence that tiger prawns feed on native Louisiana shrimp. Any potential impacts over competition for food and resources remain unknown. Tiger prawns as well as our native brown and white shrimp adopt different diets as they grow and mature and may become more predatory as body size increases.