Shell Shocked – – Florida’s Response to the Invasion of Exotic Apple Snails

As the renowned ecologist E. O. Wilson put it, “Florida rivals Hawaii in the magnitude of the threat from exotic species and for the same reasons: geographic insularity, widespread habitat disturbance, and bombardment from all sides by nonnative plants and animals.” Florida is the national gateway for foreign plants and animals for the ornamental plant, pet, and aquarium industries. In the face of this onslaught, Florida’s natural areas are losing their identity and function. I spent 35 years in DEP’s exemplary Bureau of Invasive Plants fighting over 1000 foreign plants established in Florida, now constituting 27% of our flora. My focus was on protecting the native aquatic plant communities that are so crucial to Florida’s lakes and wetlands.

As I was about to retire, the Island Apple Snail (Pomacea insularum) began to spread rapidly in Florida, efficiently devouring the very aquatic habitats I dedicated my career to protect. Consequently, I started this website to sound the alarm about exotic apple snails and assist resource managers fighting these invasive and destructive animals. Fortunately, there are many state and federal biologists who share my concern about exotic apple snails. The State of Mississippi has prohibited all members of Family Ampullariidae, calling them “destructive plant-eating apple snails.” Texas, Hawaii, California and Louisiana have identified them as agricultural pests that can negatively impact rice, taro and the production of other aquatic plants. At this time, Alabama is committed to prevent the range expansion of Pomacea insularum (see “Alabama Fights to Protect the Mobile-Tensaw River Delta). In Georgia, the Island Apple Snail has been given its highest priority for time and funding expended on control. What about Florida?

There are five stages of the response to the invasion of an exotic organism: 1. DENIAL – – “We know X is here, but it’s not a serious problem, so we don’t need to worry about it. Perhaps it won’t make it. Besides we have to deal with W, which is of more immediate concern.”2. ALARM – – “Oh, my gosh! Species X is multiplying fast and taking over the community. We must stop it.” 3. BARGAINING – – “Let’s put together rapid response teams. Perhaps, we can limit its expansion to a few areas and keep it out of critical habitat. We’ll have to divert some resources from dealing with species W, but if we have the opportunity to get on top of this we should.” 4. DEPRESSION: “We simply don’t have the resources to deal with X. Why didn’t somebody do something when it was manageable? We need better laws to keep these things out in the first place, but the commercial interests are just too strong.” 5. ACCEPTANCE: “I can’t worry about X right now, I just have discovered Y and we must deal with it now while we can!”

In September of 2005, the official position of the Florida Fish & Wildlife Conservation Commission (FWC) was: “Channeled Apple Snails [meaning P. insularum and canaliculata at that time because of taxonomic confusion] are non-indigenous to Florida and have been present in the state for over 20 years. They are a potential threat to our aquatic ecosystems, although no serious impacts have yet to be documented. Their greatest impact appears to be how they interact and possibly disrupt populations of native Florida Apple Snails, and FWC will be conducting research in this area” (see DENIAL Stage above). Subsequently, annual surveys conducted by FWC biologists of Florida’s 460 public water bodies noted a dramatic increase in the range of exotic apple snails. In 2006, four water bodies (4779 acres) were infested. In 2009, exotic apple snails were found in 75 water bodies comprising over 750,000 acres (60% of Florida’s freshwater areas). FWC will continue to take no action to prevent the spread of P. insularum “since it is widespread beyond reasonable control, and because the preliminary indications are that its impacts will be less than originally anticipated and, in some circumstances, there are beneficial effects” (see ACCEPTANCE stage above). For P. insularum, it was a very short hop from denial to acceptance.

Regarding the smaller, more isolated population of the Channeled Apple Snail (P. canaliculata) southeast of Jacksonville, it was a different story. FWC worked diligently toward eradication. Since May of 2008, the only known site of P. canaliculata, a 4-acre retention pond, has received constant attention. A crew of 5 or 6 people initially handpicked thousands of snails, then snails and eggs were collected there on a weekly basis. Recently, divers could find no snails. It is too early to be certain, but eradication may have actually been achieved . . . at least at that site. Other sites of P. canaliculata are rumored to exist in Duval County.

While FWC’s comparative lack of response to P. insularum might make sense given that it is so wide spread, the lack of concern regarding its ultimate environmental impact does not. There is simply too much taxonomic confusion to be sanguine: “Pomacea insularum and P. canaliculata pose the greatest threat to agriculture native aquatic wetland ecosystems in the U.S. [of all the apple snails]. The potential of P. canaliculata has been clearly demonstrated in Southeast Asia where its introduction . . . into Thailand resulted in dramatic changes in biodiversity and ecosystem functioning and by its devastating effects on agriculture. Some of the . . . impacts associated with P. canaliculata are almost certainly attributable to P. insularum. This species is also widespread in the region but has not been explicitly acknowledged as a serious pest because of confusion in the identification of these two species, with most of the literature referring to P. canaliculata. Pomacea insularum may therefore be likely to have a significant impact on aquatic ecosystems and pose a threat to crops in the southeastern U. S.” (Rawlings, T. A. et al., 2007).

Amazingly, it is still legal to buy, sell, and possess exotic apple snails in Florida, although last winter FWC politely asked Florida aquaculturists to stop selling P. insularum and P. canaliculata. “We work with DACS’s Division of Aquaculture to persuade culturists to stick to [selling only] the Spiketop Apple Snail (P. bridgesii), the only non-native apple snail that USDA will allow for interstate transport and one that has been in Florida for a while without apparent impacts” (Jenny Tinnell, FWC). Why allow the sale of P. canaliculata in Florida, after a heroic effort to eradicate them?

I know that some of you might be scratching your heads at this point. However, consider the plight of FWC’s Exotic Species Coordination Section with only 8 employees and an annual budget of less than $500,000. It has its hands full in this nation’s primary gateway for exotic animals dealing with Burmese Pythons, Nile Monitors, Green Iguanas, Vervet Monkeys, and 500 or so other exotic fish and wildlife species that have made their way to Florida. Against that line-up, exotic apple snails might seem rather mundane! Also keep in mind that the aquarium and pet industries are powerful economic and political interests in Florida who have successfully demanded minimal regulation. In response, “FWC has chosen to encourage responsible pet ownership rather than adopt a prohibitionist approach, which we believe would be ineffective [given] the substantial level of pet ownership [in Florida]and the industry that services this demand” (Scott Hardin, Section Leader).

Because P. insularum is clearly well-established in Florida, I hope FWC is correct in its assumption that these snails are innocuous, or even beneficial, to the aquatic environment. However, I seriously doubt it having personally witnessed P. insularum stripping the vegetation from Lake Munson, plus nearly doing so at Wellman Pond in spite of arduous snail control efforts. I admit to being very alarmed (see ALARM stage above). The next natural area that is in jeopardy near Tallahassee, in my opinion, is beautiful Lake Jackson, officially designated an Outstanding Florida Water and one of only four freshwater Aquatic Preserves in the the entire state. I wonder how this lake’s incredible, aquatic plant diversity will fare versus the on-going explosion of exotic snails. Maybe, if the Island Apple Snail strips Lake Jackson, FWC will finally take notice and put both the Island and Channeled Apple Snails on its list of “Conditional nonnative species,” those considered to be dangerous to the ecology and/or the health and welfare of the people of Florida. Until then, FWC appears “shell shocked” in the face of the rapid range expansion of exotic apple snails in Florida’s lakes, rivers and wetlands. Posted by Jess Van Dyke

For more information on FWC’s Exotic Species Coordination Section, contact:

Scott Hardin, Section Leader

850-410-0656 ext. 17257

FWC’s Non-Native Species:

Update: On July 1, 2012, Scott Hardin, former Leader of the Exotic Species Coordination Section for the Florida Fish and Wildlife Conservation Commission, joined the Pet Industry Joint Advisory Council, a group that lobbies for the interests of the pet industry in Washington, D.C.


13 Responses to “Shell Shocked – – Florida’s Response to the Invasion of Exotic Apple Snails”

  1. 1 Alex H. May 4, 2010 at 5:25 am

    Good article. It is interesting that Florida’s FWC jumped from “denial” to “acceptance” so quickly. Sounds like the right people aren’t getting the info they need, or are inundated with too much of the wrong info to care.

    I also find it incredible that only 8 employees are hired by the FWC to handle exotics. One would think that Florida should set the example for invasive species control both in scope and efficacy (and not to say you weren’t doing your job Scott!).

  2. 2 A.E.N. Writer May 4, 2010 at 2:26 pm

    Would just like to say that the Five Stages of Response to invasive species amused me greatly.

  3. 3 snailbusters1 May 4, 2010 at 3:12 pm

    I have to give credit to Jacoby Carter of USGS’s National Wetlands Research Center for the Five Stages of Response. Funny, sad, and absolutely true!

  4. 4 snailbusters1 May 4, 2010 at 3:16 pm

    Exactly, I am certainly not trying to disparage Scott or his staff. I do think that they are overwhelmed (“shell shocked”). They have an impossible job without more funding, more staff, and more political support.

  5. 5 Gary Raulerson June 1, 2011 at 8:05 pm

    Extremely useful information (all over the website) but I’d like to make a quick correction: Florida has four freshwater aquatic preserves: Lake Jackson, the Ocklawaha, Rainbow River, and Wekiva River-Middle St. Johns (where I work). We’re already “blessed” with P. insularum, and I’m gathering up any information I can find for our management plan update (to discuss current situation, research needs…). Any suggestions would be helpful, and I’m combing your site as well as the Pomacea Project site. Thanks, Gary.

  6. 6 snailbusters1 June 3, 2011 at 9:49 pm

    Thanks, Gary! I stand corrected and so does the post in question. Keep up the good work for the Real Florida!!

  7. 7 snailbusters1 July 22, 2011 at 3:20 pm

    “They have adapted to the larger Island Apple Snail . . . ” Not, exactly! Maybe, the adult Snail Kites have adapted to the exotic snails, but the juvenile kites aren’t doing well at all. See my post, entitled “Juvenile Snail Kites in Trouble.”

  8. 8 snailbusters1 July 22, 2011 at 3:20 pm

    “They have adapted to the larger Island Apple Snail . . . ” Not, exactly! Maybe, the adult Snail Kites have adapted to the exotic snails, but the juvenile kites aren’t doing well at all. See my post, entitled “Juvenile Snail Kites in Trouble.”

  9. 9 Sammii Shells Candles August 19, 2011 at 3:59 pm

    Would love some of those shells I use them for crafts… If anyone collects the empty shells I am willing to offer a small price and pay shipping cost if I could get someone to send them to me.

  10. 10 Taylor November 8, 2011 at 6:46 pm

    Say Whaaaaaaaaaaaaaaaat????

  11. 11 Bailey Resendez June 2, 2012 at 3:14 pm

    My son just got one of these out of Lake Lotela 2 weeks ago. He has added it to his fishtank. He says they are lots of these in Lake Lotela (Avon Park, Florida).

  12. 12 John July 13, 2012 at 10:59 pm

    Thanks for your work, I find this very depressing but interesting. How far north do you think they will go? I’m in Arkansas.

  1. 1 Florida Snail Kite is only found in Florida in the United States. Trackback on July 21, 2011 at 7:25 pm

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About Snail Busters

The Snail Busters Blog was created to facilitate communication between aquatic resource managers who are fighting the spread of invasive, South American apple snails, specifically Pomacea maculata (formerly P. insularum) and P. canaliculata, in the U.S.

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