Tuesday, August 30, 2011

Things in their proper place: A Sanibel perspective

Sanibel is home to many creatures great and small, as well as terra firma for various flora.

But not all of them belong here.

And when something that is not indigenous invades, it is big trouble for the native inhabitants and a lot of work for the humans who reside here as well.

One blatant example of the misplaced was that of the Brazilian pepper. Brazilian pepper was introduced from its native range in Brazil, Argentina, and Paraguay. It is a multi-stemmed evergreen shrub that grows upwards of 40’ tall and due to its invasive nature in Florida, it is responsible for destroying thousands of acres of wildlife habitat on Sanibel.

To combat the damage and danger, The City’s Brazilian Pepper Eradication Program was adopted by City Council in 1996. The goal of this ambitious program is to rid the entire island of this invasive exotic plant. The program called for six zones of plant removal with various levels of mandates. It has been and continues to be a major project for the Island.

And then there has been the introduction of "exotic" pets such as the Burmese Python and monitor lizard that now call the Island home, encroaching on the survival statistics of indigenous species in the eat or be eaten world.

In these former two cases, the cross over was purely deliberate even if the outcome was not imagined.

But much benign, though equally potentially harmful "guests", have come to Sanibel in ways that were not imagined either. The Cuban Tree Frog is a current and good example. The Cuban treefrog spreads not only via ornamental plants, but also by motorized vehicles, trailered boats, and many other unusual methods.

This spread is devastating to the indigenous frogs because the Cuban treefrog grows to twice the size of both the green and squirrel treefrogs and is capable of eating them. Furthermore, the Cuban treefrog tadpole is a superior competitor to native tadpoles, causing even more pressure on the indigenous species. It also appears to be negatively impacting certain smaller fish in the locales it has moved into.

The Cuban treefrog readily gets into homes and condominiums, swims in toilets, can be found under sinks, has been known to short out electrical boxes, and generally wreaks havoc on the environment. Studies are now under way to explore the use of biological or chemical deterrents to halt or at least slow the continued spread of this invasive species.

Sanibel is indeed a paradise, but even a paradise has to be on guard!

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