Live Island Apple Snails in the incurrent stream of Wellman Pond
Yes, 2008 was a VERY good year . . . for exotic snails in Florida, that is. My former supervisor, Rob Kipker (FWCC), just emailed me fresh 2008 data on the presence of Island Apple Snail in the public waters of Florida. Each year, his team of top-notch, aquatic biologists inspects the Sunshine State’s 1.25 million acres of lakes and rivers with public boat ramps. Their primary mission is to survey aquatic plants, but for the past three years, Pomacea insularum has been on their list of species to mark “present” or “absent.” Rob wrote, “This is not a snail survey in the sense that we are documenting range, rather it is an indication of which of the 460 public waters in Florida currently have populations of the Island Apple Snail. Use at your own discretion.” O.K. and thanks, Rob!
The results of the 2008 survey reveal that 50 public waters (11%) are now are infested with the exotic Island Apple Snail. That’s bad enough, but the situation is worse when one takes into consideration the size of the affected waters. Some of Florida’s largest are on the list. The “800 lb. gorilla,” of course, is the Lake Okeechobee (448,000 ac), largest lake in the southern U.S., but Lakes Tsala Apopka (19,000 ac), Toho (31,500 ac), Kissimmee (35,000 ac), and the St. John’s River (96,000 ac) also have the exotic snails. Therefore, in terms of surface area, most of Florida’s public waters (55%) have populations of Pomacea insularum.
What about the future? There is every reason to believe that the Island Apple Snail will also have a very good 2009. There is a growing awareness that tropical cyclones play a major role in the dispersal of exotic species. The classic example occurred in 1992, when Hurricane Andrew destroyed much of the Miami Zoo, releasing parrots, baboons, orangutans, wallabies, capybaras, and more. One reptile dealer lost 10,000 geckoes, and a private research institution, 2000 monkeys. The hurricane facilitated a population explosion of large feral iguanas. South Florida will never be the same.
The dispersal of aquatic snails by tropical cyclones though more subtle is no less dramatic. In July 2000, exotic apple snails were discovered in the American Canal near Alvin, Texas (between Houston & Galveston). In June 2001, severe flooding from Tropical Storm Allison dispersed the snails throughout the entire region. In 2008, Cyclone Nargis hit Myanmar (formerly “Burma”) and spread the Golden Apple Snail (Pomacea canaliculata) into the vast rice production areas. “We have never seen so many. They have destroyed our fields,” said one rice farmer (see News Page).
In August of 2008, Tropical Storm Fay made a record four landfalls in Florida, zigzagging from land to water, and causing major, often record, flooding in 27 counties. Rainfall amounts included 27” in Melbourne, 23” at Cape Canaveral and 21” at Palm Shores. The St. Johns River overflowed in Jacksonville. Where I live east of Tallahassee, we received over 20” in a few hours. I’ve never seen flooding like that here. How can such a weather event not exacerbate the dispersal of the invasive apple snails in Florida? I have to believe that Pomacea insularum will put on quite a show in 2009. Happy New Year!! Posted by Jess Van Dyke
For more information on the survey, contact:
Invasive Plant Management Section (FWCC):