Dr. David L. Strayer Freshwater Ecologist Share: March 25, 2012 Invasive Species, Environmental Policy I write today about the science and politics of snakes. You may have heard that non-native Burmese pythons (probably released by a pet owner) are now established in Florida's Everglades, where they have developed a taste for the local cuisine. A recent study shows that local wildlife populations plummeted following the spread of these 18-foot-long predators. Roadkill surveys (now there's an attractive job) show that raccoons and opossums are down by 99 percent, deer are down by 88 percent (probably not entirely a result of the pythons, although they do eat deer as large as 76 pounds), bobcats are down by 88 percent and rabbits have disappeared entirely. Biologists have captured and killed 1,500 pythons in the Everglades, but this hasn’t stopped their spread, and they probably are here to stay. Another recent scientific study emphasizes that the escape of these pythons is not an isolated occurrence, but part of a larger pattern. An amazing 137 species of foreign reptiles and amphibians have been introduced into Florida, of which 56 species are now established in the wild. Many of these species were first found outside poorly secured animal importation and breeding facilities, from which they crawled, hopped, or slithered to freedom and into our wetlands and backyards. The pet trade and its customers are leaking species across Florida and across the country. Of course, most of the animals released from the pet trade die in nature, or do not cause problems even if they do establish. But as the pythons remind us, some species do cause big problems and are hard to control. A more local example of “pets gone wild” reinforces this point. Northern snakeheads, Asian fish widely sold by pet stores, apparently were released into Ridgebury Lake in Orange County, where they began to reproduce and spread. Snakeheads are large predators that could spread through the Hudson Valley and beyond and have a huge effect on our ecosystems. Consequently, the state Department of Environmental Conservation decided to try to eradicate this population. The effort in 2008-09 killed 250 snakeheads and 8 tons of other fish and cost at least hundreds of thousands of tax dollars. Now we’re all hoping that it worked, so that we’re not facing larger damages in the future. So what ought we to do about all of this? In response to the situation in the Everglades, the federal government last month finally prohibited the importation and interstate transfer of Burmese pythons. This action is years too late, and will probably be just slightly more effective at stopping the invasion than standing at a window and singing “rain, rain, go away” to stop a summer rainstorm. Here are some options. First, we could continue with business as usual. This is easy, maximizes profits for the pet trade (an important and valuable industry), and allows pet owners to buy whatever they like. When harmful ex-pets do cause problems, we all pay to clean them up, and just accept the ecological and economic problems that result when we can’t clean them up. Second, it might sound appealing to make pet breeders and pet owners pay when their pets escape and cause problems. However, once a problem arises, it rarely is possible to track down the person who released the problematic pets. Also, few pet owners have deep enough pockets to pay for the huge damages that result when things go bad. Third, we could impose a small tax on the pet industry to set up a standing fund to pay for programs to educate pet owners about the dangers of releasing unwanted pets, campaigns to control or eradicate unwanted escapes, and compensation for damages suffered as a result of escaped pets. Finally, we could develop a rational national approach that would allow the pet industry to import and sell only species that can be shown to be unlikely to survive in the wild or be benign if they do escape. Whatever we decide to do, it would be nice to have a policy that is fair and effective at minimizing problems from escaped pets, instead of just wringing our hands when a problem arises. Share: Dr. David L. Strayer Freshwater Ecologist Dave Strayer is a freshwater ecologist whose work focuses on measuring the long-term effects of zebra mussels on the Hudson River ecosystem, and understanding the roles of suspension-feeding animals in ecosystems. Strayer also works on broader issues in freshwater conservation ecology and invasion biology.