Featured Research

from universities, journals, and other organizations

Research Finds Alligator Problems Also Evident In Less Polluted Lakes

Date:
February 9, 1998
Source:
University Of Florida
Summary:
Reproductive and hormonal problems documented in alligators living in a polluted Florida lake have turned up in alligators living in other Florida lakes thought to be more insulated from pollutants, say researchers at the University of Florida.

Writer: John Lester, JCLester@ufl.edu

Related Articles


Source: Louis Guillette, (352) 392-1098, ljg@zoo.ufl.edu

GAINESVILLE, Fla. --- Reproductive and hormonal problems documented in alligators living in a polluted Florida lake have turned up in alligators living in other Florida lakes thought to be more insulated from pollutants, say researchers at the University of Florida.

"These long-term studies are the answer to finding out how environments change over time, naturally and under man's hand. This should be a wake-up call. We have to make sure that similar problems are not occurring in ourselves," said UF Professor of Zoology Lou Guillette.

A research team led by Guillette made headlines in 1993 when they said pesticides could be responsible for sexual deformities and a previous population decline of alligators in Lake Apopka near Orlando.

That lake suffered from a severe pesticide spill in 1980 and commercial development on its shores.

"Everyone accepted the fact that Lake Apopka had a problem," Guillette said. "We now have the same problems on another lake."

Preliminary tests on Lake Okeechobee, Florida's biggest lake, showed the research team many of the same problems it had seen before: lower testosterone levels and small penis size in male alligators. In addition, tests also showed a new problem: altered thyroid hormone levels. The results are scheduled to appear in the Feb. 17 issue of the scientific journal Environmental Toxicology and Chemistry.

Also during the studies, researchers for the first time found possible effects of environmental toxicants on the thyroid, a critical regulator of growth in animals.

Biology Professor Drew Crain, a former student of Guillette now teaching at the University of Mississippi, said the study shows that problems found in Lake Apopka alligators are confined neither to that lake nor to one system in the animals.

"Previous studies have focused on the hormones associated with reproduction -- the steroid hormones testosterone and estradiol -- but now we have evidence of disruption in other endocrine-controlled systems," Crain said. With funding from the Environmental Protection Agency and the National Institute of Environmental Health Services, the team wanted to see if the past findings from the Lake Apopka alligators were unique to that highly polluted lake.

"We were asking, ‘Are we getting the same effects with lower exposure, exposure that we would assume to be normal background?'" Guillette said. Guillette said alligators are the perfect animals to study because they are predators at the top of the food chain, have a long life span and take several years to mature.

Researchers caught, measured, tagged and withdrew blood from 50 alligators each on Lake Okeechobee, Lake Apopka and Lake Woodruff, a relatively pristine lake located in a wildlife refuge. When the blood was tested and compared the results from the Lake Okeechobee alligators were very similar to the results they obtained from Lake Apopka.

"There was a 75- to 80-percent reduction in testosterone levels in males" when measured against the alligators in their control lake, he said. Hormonal irregularities found in Lake Okeechobee alligators were not as severe across-the-board as the Lake Apopka alligators, but a number of measures were troublesome, he said.

"The thing that now concerns us about Lake Okeechobee is we're no longer talking about a lake that has a Superfund site. We're no longer talking about a lake with a major pesticide spill. This is a huge body of water."

Guillette had help from Crain; Daniel Pickford, another former student of Guillette's; Franklin Percival of UF's Florida Cooperative Fish and Wildlife Research Unit; and Allan Woodward of the Florida Game and Freshwater Fish Commission.


Story Source:

The above story is based on materials provided by University Of Florida. Note: Materials may be edited for content and length.


Cite This Page:

University Of Florida. "Research Finds Alligator Problems Also Evident In Less Polluted Lakes." ScienceDaily. ScienceDaily, 9 February 1998. <www.sciencedaily.com/releases/1998/02/980209154754.htm>.
University Of Florida. (1998, February 9). Research Finds Alligator Problems Also Evident In Less Polluted Lakes. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/1998/02/980209154754.htm
University Of Florida. "Research Finds Alligator Problems Also Evident In Less Polluted Lakes." ScienceDaily. www.sciencedaily.com/releases/1998/02/980209154754.htm (accessed October 24, 2014).

Share This



More Plants & Animals News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. Video provided by Newsy
Powered by NewsLook.com
Weird-Looking Dinosaur Solves 50-Year-Old Mystery

Weird-Looking Dinosaur Solves 50-Year-Old Mystery

Newsy (Oct. 23, 2014) You've probably seen some weird-looking dinosaurs, but have you ever seen one this weird? It's worth a look. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins