Each year aquatic biologists from Florida Fish and Wildlife Conservation Commission survey all of Florida’s public water bodies – – lakes and rivers with both state sovereignty and public boat ramps. This effort by the Invasive Plant Management Section focuses on aquatic vegetation, especially invasive, exotic plants, such as hydrilla and water hyacinth. In 2006, however, Pomacea maculata was added. Rob Kipker, my former supervisor there, is kind enough each year to provide me with the current data. His chart above shows a steady increase in the number of water bodies invaded by the South American snail. As of 2014, 36% of Florida’s public 450 waters are affected. Even more alarming is that Pomacea maculata can be found in 72% of Florida’s lakes and rivers by area! Jess Van Dyke
Published December 10, 2008
Tags: exotic, Pomacea, Snail Kite
Check out this site’s Recent Publication Page for reports published since 2000. Please let me know what is missing. For instance, I just found new research on the effects of Pomacea insularum on the Snail Kites in Florida:
For his Master’s Thesis at UF (see Recent Publication page), Christopher Cattau recently found that the exotic snails (Pomacea insularum) that have invaded Lake Tohopekaliga were 69% larger than the native apple snails (P. paludosa). The larger exotic snails require longer handling times for Snail Kites (Rostrhamus sociabilis plumbeus), an endangered raptor in the U.S. that exhibits an extreme form of dietary specialization. The larger size of the prey leads to increased drop rates and depressed capture rates. However, the average exotic snail weighed 3.5 times the native and provided 2.7 times energy than the average native snail. Consequently, the effects of the exotic snail on foraging behavior do not have negative energetic repercussions for adult kites. In fact, he found that adult kites are attracted to Lake Toho and that the relative contribution of the lake to the range-wide nesting effort increased from 6% to 33% after the invasion of the exotic snail.
The invasion of exotic snails is a problem for juvenile Snail Kites, however. The exotics were 4 times harder to capture, plus drop rates and handling times for the exotic snails were over 5 times those of the native. These effects on juvenile foraging behavior lead to insufficient daily energy balances and suppress juvenile survival. Given the critically endangered status of the snail kite and the propensity of the exotic apple snail to spread, serious management and conservation initiatives that address the exotic apple snail are necessary to prevent further deleterious consequences for the kite population in Florida.
Posted by Jess Van Dyke
For more of Jim Neiger’s incredible images of Snail Kites on Lake Toho:
Published December 5, 2008
Tags: exotic, invasive, Pomacea
It was a rainy December day, so I finally created eight pages for this new Snail Busters site. My purpose here is to speed up the transfer of information on controlling the South American apple snails that threaten our lakes, rivers, and marshes. It won’t work without the input of those on the front line fighting these destructive animals. Please feel free to comment. Let’s work together to stop the damage to aquatic ecosytems and farms! Posted by Jess Van Dyke