Wednesday, April 25, 2012

Armored Catfish: eroding lake shorelines in Florida

The fish pictured above is a Loricariidae, or armored catfish.  As a teen, I had several freshwater aquariums and this particular catfish was a common fixture in my tanks as a bottom feeder and window cleaner as it fed on the algae that would grow on the aquarium glass.  But they were always just an inch or two long, a juvenile (as is often the case with many of the fish in the aquarium trade).  Cute little guy, nosing around scrubbing the small porcelain hard hat diver resting on the gravel bottom. 

However, the beast above is no welcome visitor to the freshwater lakes and streams in southern Florida.  It is another invasive species that the state is having to contend with.  While the beautiful but voracious lionfish plays havoc with coral reef fish populations off the eastern Florida coast and into the Caribbean, the armored catfish, so named because of its tough scales and spiked fins, is damaging fresh waterways by devouring aquatic plant life which causes erosion of the local shoreline by as much as 10 feet.   Full grown adults also  lay their eggs in 18-inch deep, 4-inch wide holes along the shoreline which can pose a hazard to people walking along the water's edge.

In South America, where the armored catfish is normally found, the balance of nature - the level of plant growth, the predators that feed on the catfish - all help to maintain a proper balance in the catfish population and whatever damage it inflicts on local aquatic plant life.  But in southern Florida it is running amok as it already has for several years in Texas waterways.

The armored catfish joins a long list of invasive species that include, in addition to the lionfish, the ravenous snakehead fish in the Northeast, freshwater zebra mussels in the Great Lakes, and the Caulerpa taxifolia seaweed in California, just to name a few.  And as is often the case with these unintended invaders - sometimes the result of being castaway pets or sometimes brought in from distant waters by freighters carrying them or their eggs/spores in the bilgewater - eradicating them can prove to be difficult and costly.  Estimates to correct shoreline erosion and set up various methods to deter the catfish have been as high as a million dollars.

In describing the situation, contractor Chip Collins, owner of Lake Erosion Restoration, said, "One, it's a safety issue.  Two, it's a curb-appeal issue."

"If we do nothing, I think eventually we're going to end up with a sinkhole," said Suzanne Ury, president of the Royal Lakes Homeowners Association.

It's always a difficult decision, deciding on how best to deal with an invasive species.  Will we do more damage in trying to eliminate it, or should nature take its course and over time reach a new balance.  It was mankind's clumsy handiwork that put it into a foreign ecosystem; do we have the ability to correct the situation or make things worse?
Source: Florida Sun-Sentinel 

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