Posted on 05/18/2004 5:50:34 AM PDT by Pharmboy
The worldwide decline in frogs and other amphibians has been well documented, though the reasons for it are less clear. Scientists have suggested many possible factors, including climate change, disease and increased exposure to ultraviolet radiation and pesticides.
But for some species, a major reason could simply be that they are being eaten — by predators introduced into their habitat. A researcher at the University of California at Berkeley has shown this to be the case for a frog in the Sierra Nevadas. The researcher, Dr. Vance T. Vredenburg of the Museum of Vertebrate Zoology at the university, demonstrated that rainbow and brook trout, introduced over the last century for sport fishing, are largely responsible for the decline of the mountain yellow-legged frog. He reported the finding in the current issue of The Proceedings of the National Academy of Sciences.
But Dr. Vredenburg wanted to show the effects of the fish without harming more frogs, which exist almost exclusively in declining populations in California mountains. "I had two choices," he said. "One was to actually introduce fish into a frog lake and watch what happens. But I couldn't do that in any conscionable manner."
Instead, Dr. Vredenburg studied what occurs when the trout are removed. Beginning in 1997, he laboriously removed the fish from five lakes in a remote region of Kings Canyon National Park in the central Sierra Nevada. In a year or two, Dr. Vredenburg found signs that frogs were returning.
To determine exactly how the fish affect the frogs, he conducted another experiment, placing a few rainbow trout in small cages in the lake and introducing some frog eggs. The trout, he found, ate the tadpoles emerging from the eggs. "The fish would sit there and pick them off one by one," he said. Taken together, Dr. Vredenburg said, the two findings provide strong direct evidence of the trout's role. "The fish in this case obviously are a major player in the decline of this frog," he said.
The solution is easy. If you want to restore the frog, just remove the fish, which the National Park Service has begun to do. "The most exciting thing about this," Dr. Vredenburg said, "is that this is one study of frog decline where we can actually do something about it."
Look out your window, folks, and see if any pigs fly by...
The frogfish (Antennarius multiocellatus) suffers from divided loyalties.
There is no shortage of frogs. If there is any doubt, I challenge anyone to try and sleep in my neighborhood with their windows open.
No shortage of frogs where I live out here on the farm. We are serernaded by "karaocroaky" all night. :>)
"serernaded"
serenaded
Yup. And in some place the "shortage" is turning out to be a full-scale invasion, like in Australia, or a rapid colonization like in Germany and Belgium.
"What?? It wasn't Bush's fault? And this from the NY Times?"
Not directly, but it is indirectly. I believe if anyone is to blame, it'd be Gale Norton. She's the big business, anti-environment, oil polluting, natural resource depleting woman in charge in President Bush's cabinet. So, yes. It's most definitely President Bush's fault. :)
On another note, what is this scientist doing removing fish from there lake home? Doesn't he know they have feelings? :)
Hmmmmmm ... perhaps I can start a frog export business. We've got them all over the place. So much so that the snakes are getting fat, and numerous.
I was looking for something to watch on cable last night, so I was viewing the TV Guide channel that lists all the options.
Who should appear on the TV Guide channel, but Rob Reiner, criticizing the President for his environmental policies. Saying things like "We've got to get Bush out of there before he destroys the environment."
You can't even watch the "listings" on TV without having to listen to some Bush bashing!!!
I thought this was about the French.
Good article anyway.
Laboriously removed the fish? Sounds like he did a whole lot of fishing. Now that's my kind of research!
With a grant, he can probably prove that such cycles can oscillate as the populations ebb and flow. If he's lucky, Middle School biology textbooks will soon be discussing this fascinating tidbit.
"Stifle yourself, Meathead."
But...but... we know that man is responsible for ALL ecological problems...
Frog legs ... yum!
Gotta love it.........getting government grants to go fishing!!!!!
We have frogs, toads, anoles, geckos, mockingbirds, etc.
It is LOUD here. And we live IN town.
We also have occasional ALLIGATORS here! In town. I guess THEY get hungry too.
If only.
Ya beat me to it!!!! LOL!
Sure wish I could collect a paycheck for two years of fishing!!!!
So it is YOUR fault!!! LOL
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.