A Plague of Frogs; Unraveling an Environmental Mystery by William Souder

Consider frogs. They’ve been around for 350 million years, and that’s a while. They are essentially funnels with a big mouth at one end, and at the other, big legs to escape predators with. They’ve evolved ingenious techniques for surviving serious cold and heat and drought. They seem well adapted to anything nature wants to throw at them. And so it is. They’ve survived astronomical catastrophes, drifting and colliding continents, glaciations, and mass extinctions of all sorts. Everything except us, possibly. It is a fact that frog populations are in decline everywhere, even in pristine environments where we haven’t yet pulled our ugliest stunts.

But on August 8, 1995, the frogs’ saga took a nasty turn. A group of middle school children visiting an environmental learning center in Le Sueur County, Minnesota, found an entire population of leopard frogs suffering from all kinds of horrid deformities. Extra legs, extra arms. More limbs than a centipede. Only one eye. Open the mouth and there’s the other one. A hell-hole of frog horrors. The Minnesota Pollution Control Agency was called into to view the spectacle, and soon the scientific community was in a hubbub. In A Plague of Frogs, William Souder, who covered Minnesota’s deformed frogs for the Washington Post, reviews that scientific hubbub following the discovery in Le Sueur County.

It took awhile to dig out, but the literature is there. It just took a French Canadian to make it available to language deprived American scientists. Deformed frogs have not been all that uncommon. Frog deformation does happened quite naturally. But the literature also demonstrated that what was going on in Le Sueur County was of entirely new order of magnitude. And once the news got on the Internet, deformed frogs, soon found all over Minnesota, started popping up in other places as well. Canada. Vermont. Japan. California. Oregon.

Two hypotheses immediately presented themselves. The first was that the frogs were being exposed to some type of deforming pollutant. Simple, find it and get rid of it. Not so simple. In Minnesota, 15 types of pesticide are applied three times a year in addition to several fungicides and insecticides. These breakdown into.what? Nobody knows. Which of the chemicals or its ‘daughters’ was the guilty party. Possibly it was two or three of them in combination, and anyway, how and when were they delivered? In the water? In the sediments? In the vegetation?

The second hypothesis was that it was a parasite causing the deformities. Some are known to do that. But why would a parasite so thoroughly massacre its host population? And why now, if not a hundred years ago?

Possibly the answer lies in a synergistic combination of toxicants and parasites. Possibly it is neither, but global warming or increased UV radiation, or those in combination with toxicants and parasites. Or possibly frogs are just at the end of their evolutionary rope, and there’s no help for it.

With all the possibilities, designing data collection techniques and laboratory experiments became a scientific nightmare all its own. Key components of field observations weren’t gathered and laboratory findings just didn’t jive with field observations. Yes, this toxicant will cause deformities in the lab but in the field the toxicant just isn’t present. Oh, well, time to whip the slate clean and start over. Let’s hypothesize that…and here we go again.

To make a long story short, we don’t know much more about frog deformities than we knew on August 8, 1995. But in telling the tale, Souder tells us a lot about how science, good and bad, is done by big and small bureaucracies and by individual scientists. He takes the reader with ease and daring through a lot of complex ideas from evolution, from embryology, from toxicology. And he explores a lot of interesting personalities from middle school teachers, to landowners worried about being blamed for things they don’t understand, to simple and contented professors in backwater colleges, to science’s most arrogant and smug geniuses.

Much of this is very troublesome. Biologists who are concerned with organisms are themselves an endangered species being replaced by molecular biologists in their laboratories and by biology teachers preparing students for medical schools and owning BMWs. We just don’t have the scientist who can tackle a major field problem concerning basic organisms, living critters. Agencies squabble and fight among themselves and can’t protect their incomplete data from an incompetent public. Landowners are too frightened to cooperate. Professors withhold data and findings the public has paid for in hopes of achieving more prestigious publication, and thereby faster promotion and tenure. And finally, and most disturbing, we may know a lot, but we don’t know diddle-squat about how life on this plant works. We’ve a lot of equipment for measuring this and that, and a lot of theories and ideas, but not the organization or management to tackle any major environmental or ecological problem. The frogs are trying to tell us something, but something too complicated for us to understand.

But, if you aren’t into frogs, what do you care? The answer, beyond our simple lack of preparation for understanding what is going on among the frogs, is that frogs are supposed to be a ‘sentinel species’, itself a controversial concept in science. Frogs are major predators who eat, in their specific habitat, pretty far up on the food chain. If the frogs of the world are doing well, we have little reason to worry. If the frogs are doing badly, we have reason to be anxious. The frogs aren’t doing well so we should be worried. As one of Souder’s scientists is made to observe, ‘We don’t have to save the world. We have to save ourselves.’