Sex and the Single Reptile: Reproductive Problems in Florida Alligators May Be an Early Warning for People

Article excerpt

Alligators with undersized testicles may seem like a problem only for other alligators, but scientists at the University of Florida (UF) argue that what happens to 'gators today may well happen to humans tomorrow. In fact, the alarming reproductive problems of Florida's alligators may be surfacing in largemouth bass, a sign of widespread lake pollution.

The focus of this alarm is Florida's third-largest freshwater lake, Lake Apopka, covering 30,000 acres near Orlando and once an internationally recognized mecca for bass fishermen. Now only splintered remnants of once-numerous fishing camps remain because of the lake's shrinking bass and bluegill populations.

Scientists decided to examine bass as well as alligators because both are at the top of the food chain and both are long-lived, giving them a chance to accumulate contaminants in their bodies over time - like humans. "Theoretically, we have data that suggest this could be a fundamental problem elsewhere in Florida and the U.S. It's definitely a canary in a coal mine," suggests Louis Guillette, a UF zoology professor.

Lake Apopka has suffered from what may be called "battered lake syndrome" for decades. Because of relentless development, its alligator, turtle and bass populations have been on the decline at least since the 1980s. UF scientists, who recently received funding for a five-year study of the lake and its environs, have documented a near-90 percent drop in Apopka alligators over 20 years.

A chemical spill in 1980 and ongoing agricultural pesticide contamination are the primary reasons for the lake's problems, according to researchers. They found that fewer male alligators are being born, and those that are "don't appear normal," explains Tim Gross, a reproduction endocrinologist at UF. "When their gonads are sectioned, they're abnormal. Their hormone production is abnormal as well." Both females and males are showing abnormally high levels of estrogen. Low levels of testosterone are showing up in male alligators and bass.

The lake's biggest battering took place in 1980, when the now-defunct Tower Chemical Company spilled large amounts of the pesticide Dicofol into a stream that drains into the lake. The chemical company's buildings have since been designated a Superfund cleanup site by the U.S. Environmental Protection Agency (EPA). The ingredients in Dicofol, including DDT and its derivative, DDE, are called "endocrine disrupters," which can cause hormonal imbalances that result in reproductive problems.

"We're eating the fish and we're exposed to these same environments where these contaminants are occurring," Gross says. "It may not be too far in the future that we see fallout from it. For humans, it doesn't mean gross deformities, but people less and less able to have offspring. …