Energy and Environment Reporting for Texas

4 Theories on How Tiger Prawns Ended Up in the Gulf of Mexico

Courtesy of Acme via Flickr's Creative Commons http://www.flickr.com/photos/acme/with/28902101/

When you post a story online you never quite know what to expect. Some stories attract an army of visitors right out of the gate, while others fade into obscurity with nary a visitor.

Then, there’s the slow burn. It’s the news story that doesn’t initially inspire much interest, but gradually attracts a steady amount of traffic. It’s the tortoise in the race.

Recently, the tortoise has been a Tiger Prawn.

When I first reported on the arrival of foot-long Asian Tiger Prawns in the Gulf of Mexico, fewer readers took noticed than I had hoped. But over time, the piece has provoked some comments and continued to attract visitors. For all of you concerned or curious about this invasive species and it’s impact on the Gulf ecosystem, here are several theories of how the prawn first established itself in the Gulf of Mexico:

  1. Thanks, South Carolina. In 1988, an accident at an fish farming facility in South Carolina inadvertently released pond-raised tiger prawns into the ocean where they were caught off shore for years afterward. “Like a lot of introduced species, they got out, everybody was concerned, but nature took its course and we never saw them after 91,” says Texas Parks and Wildlife Leslie Hartman, “until again after 2006.” Hartman is participating in genetic testing to see if the Tiger Prawns that are now showing up in shrimping nets in the Gulf could be related to those South Carolinian escapees.
  2. Blame it on the Ballast. Ballast is weight that ships take on to stabilize their voyage. A lot of strange things get carried around the world in the ballast water of ocean-going vessels. If a ship is in Asia and takes on water to stabilize its journey to the Gulf, who’s to say some Tiger Prawns couldn’t come along for the ride? Ballast water has been blamed for the introduction of many invasive species, including the appearance of the hyper-destructive zebra mussels to the Great Lakes.
  3. Maybe It Was a Hurricane? While there are no known Tiger Prawn aquaculture operations in Texas, they do exist in the Americas.The Houston Chronicle speculates that “the prawns may have escaped from flooded industrial shrimp ponds in the Caribbean Sea during recent hurricanes.” Martin Bourgeois with the Louisiana Department of Wildlife and Fisheries says he’s heard the theory that Tiger Prawns came “after accidental releases from aquaculture facilities in central America or the Caribbean.” But he says he doesn’t know “if we’ll ever figure out where they came from.”
  4. Their Introduction Was Intentional. Remember about ten years ago when the U.S. was about to be taken over by the Snake Head Fish? The media made quite a fuss over the voracious predator that can actually walk on land, though the Asian Carp has likely had a worse impact as an invasive species.  What both those fish have in common is that they were probably both intentionally introduced. Is it possible someone has been seeding the Gulf with Tiger Prawn?

Efforts to get to the bottom of the Tiger Prawn mystery continue, and Texas Parks and Wildlife’s Hartman expects genetic testing to yield some answers by the end of this year. Why is it important to know where the prawn came from?

“If you do not know where they’re coming from, you cant stop the introduction of additional ones,” said Hartman.



  • Drgiao

    Vietnamese fishermen.

  • Anonymous

    A direct, inevitable and, most likely, irreversible effect of globalization. Any evidence of native North American species showing up in Asian or European  ecosystems, i.e., does it work both ways?

    • Anonymous

      Corn, potatoes, chili peppers, and hundreds of other species of plants, and various animals — insects, reptiles, mammals, etc. — once indigenous to North, Central and South America.

  • alaska fisherman

    Irresponsible aquaculture operations.  They are totally in control of their livestock until an accident happens or human error.  Non-indigenious species should not be allowed to be raised in a marine environment.  Invasive deleterious species are straining and altering eco systems all over the world.  Aquaculture, if allowed at all, needs to be land based, closed containment, and 100% sterilized livestock.  Commercially economical aquaculture usually requires massive amounts of pharmaceuticals and hormones to keep the fish alive and grow fast, not a healthy choice.

  • Nicholas Mcgill

    Alien invasion hysteria is just that. By that standard, humans are the worst species in recent geologic history. 

  • Zow77rdr

    Can you eat them???? … I say Old Chap, throw another Tiger Prawn on the barbie, ah?!

    • Trevor Smith

      Not so fast.  They destroy native species of all types, and they also destroy oysters. 

  • Jana

    Maybe the guy from Forrest Gump

  • Anushgarun

    Do they have any kind of negative/positive effect on the gulf? How do they compete with other  prawn species there? If it doesn’t really have a terrible effect on the Gulf then no biggie right? 

    • Trevor Smith

      They have a terrible effect.  Yes, you can eat them but they destroy the several native species, and they also destroy oysters. 

  • Rabatvilla

    Another example of stupidity at work.  The ban of all invasive species needs to happen and fast.  Time and time again we read how some person, by accident or on purpose, lets an invasive species into the eco system with disastrous results. One the worst happen in the early 1900′s when a group let 19 breeding pairs of staring go in central park.  Today they number in the hundreds of millions and cause millions, if not billions, of dollars in damages every year through this nation.  Just ban them all, make ships dump their ballast way out in the Atlantic or only allow duoble haul ships into ports.  

  • I would guess they are being brought here by SE Asian refugees who work in the fishing industry in the Gulf 

    • That would be what George W. Bush likes to call, “speculation”.

    • DrGiao

      Good point.  Being Sino-Vietnamese I am familiar with the shrimping industry in the Gulf and the large number of my countrymen who would have few qualms about introducing tiger prawns if they could profit.  Same with gill nets.

  • hidejii

    No matter how well-considered ideas were introduced to protect our planet, we could not control human activities perfectly. In some sense, our histry, develpment including extending crops worldwide came from those inevitable our foot prints whether on purpose or by chance they would be. Moreover, birds’ migration  might be a fuctor that make more impact on environment.

  • “A direct, inevitable and, most likely, irreversible effect of globalization.”

    This. Humans have been globalizing since they first learned how to sail, and the physical boundaries that used to geographically isolate less competitive species are disappearing. As a result, aggressive more dominant species will eventually occupy the majority of niches they can survive in.

  • Moriah01

    I would not eat them , where ever they came from.

  • Nude0007

    I wonder if regulations on when ships can take on or dump ballast would make a difference or maybe some sort of filters on the ballast intake system?

    If these things are edible, it would seem like a good thing unless they do something we don’t want to other species or the environment.

  • Cai

    Just like the Asian Carp, I say let’s eat them all.  We’re humans, we’re really good at wiping out populations of edible critters. 

  • Evie

    Interesting article.  Would like to have seen the effects of Tiger Prawns in the Gulf. i.e., why is this important, and what does it mean to the current ecosystem.  We could simply be the spectators of a historic moment when the ecosystem changes.  It may be upsetting at first, but nature has a way of balancing these things out over time.  The current ecosystem will be replaced with a  new one that is different, but not so disastrous as some would lead us to believe. 

    • Mose Buchele

      Thanks for reading Evie,
           Our first report on Tiger Prawns got into more depth about why this could be a problem. Some concerns: they eat shrimp, crabs and other species indigenous to the Gulf. They also may possibly carry diseases for which native species have little natural resistance.
           You can read/ hear that story here:    http://stateimpact.npr.org/texas/2012/01/06/tiger-prawns-roar-into-the-gulf-of-mexico/

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