Pesticide Action Network Updates Service (PANUPS)
April 30, 1999
Nearly 800 birds, primarily white pelicans, have died since pesticide-contaminated farmland was flooded in July 1998 to create a marsh near Lake Apopka in Florida. Experts fear the death toll may be even higher since thousands of migratory birds have fed at the wetland restoration project. State officials managing the lake, however, say they have no plans to monitor it for pesticides.
Preliminary tests by U.S. Fish and Wildlife Service pointed to organochlorine chemicals as the source of the problem. The soils in the area are known to have high levels of dieldrin, DDT and toxaphene. "The birds are preying on fish in ditches and small pools northeast of the lake," said a Fish and Wildlife Service official. "The birds become sick and die after eating the contaminated fish." In addition to white pelicans, bodies of endangered wood storks, great blue herons, cormorants, egrets and several bald eagles have also been found.
The Fish and Wildlife Service expressed concern that mammals, including humans, who have had direct contact with soils from the area may also be adversely affected. The agency issued a warning that people should avoid contact with any sick or dead birds and should avoid eating fish caught in the area.
The local water management district is in the midst of a US$100 million project intended to restore Lake Apopka, the largest body of severely polluted water in Florida. The district bought about 13,000 acres of farmland that had been drained by farmers in the 1940s and 50s and planned to flood it so the land could eventually become part of the lake, as it had been in previous decades.
The water district flooded the farmland in July, and by late fall large numbers of migratory birds were attracted to the marsh. As many as 41,000 birds were in the area at any one time. In late November, large fish-eating birds began to die. In early 1999 in response to the deaths, the district drained the water from the farmland back into the lake, and in February the birds began to leave. Florida state agencies then began receiving reports from residents in other parts of Florida that white pelicans were falling out of the sky.
Early in the project, tests indicated that a variety of pesticide residues were present on the land that was to be flooded, and some scientists warned that this could result in reproductive problems in wildlife that came to the area. One study singled out fish-eating birds as those being most at risk.
A Florida Audubon ornithologist, Gian Basili, has speculated that birds feeding in flooded farm fields on Lake Apopka may have been dying for years at levels that were too low to attract attention. Basili said the recent death might be partly explained by the sheer numbers of birds that descended on the area.
Lake Apopka was also in the news several years ago when researcher Lou Guillette and his colleagues discovered alligators with reproductive problems such as stunted penises that stemmed from exposure to pesticides that were dumped into the lake as the result of an accident.
Sources: The Orlando Sentinel, February 11, February 27, March 10, March 11, March 12, April 2, and April 12, 1999. U.S. Fish and Wildlife Service press release, February 17, 1999.