News and Activities
Hundreds of Birds Die in Florida
Date Posted: June 15, 2001UPDATE: JUNE 11, 2001 The U.S. Fish and Wildlife Service today released detailed laboratory results from the 1999 Lake Apopka area bird deaths to members of the Technical Advisory Group which includes representatives of interested state, local and federal entities. The laboratory data show elevated levels of organochlorines (pesticides) in the birds tissues, including toxaphene, dieldrin and DDT. Some necropsies, including one for an endangered wood stork, prepared by the National Wildlife Health Center in Madison, Wisconsin, determined that levels of dieldrin alone were sufficiently high to cause death.
The Service is continuing to investigate the bird deaths.
BACKGROUND: SEPTEMBER 1999 The north shore of Lake Apopka, Florida, is a site where farms were developed in the early 1940's to help produce food during WWII. To create these farms, a portion of the lake was sectioned off using a dirt berm and the water was pumped off the land into Lake Apopka. For more than 50 years, this area was farmed. Tons of pesticides such as DDT, dieldrin, chlordane, and toxaphene were used. Water from the lake was regularly pumped onto the fields for irrigation, and each year the fields were flooded with a few inches of water for short periods of time to control unwanted plant growth. By the 1980's, water quality in the lake had decreased dramatically. This decrease in water quality was attributed not only to agriculture, but also to waste water treatment plants located along the lake. Also around this time, scientists began investigating the reduction in young alligator populations around the lake. It was later determined that residual contamination from a Superfund site on the south side of the lake was responsible for endocrine disruption in the alligators and significantly reduced penis size in young male alligators. In an effort to improve the lakes water quality during the 1990's, wheels were set in motion for Florida's St Johns River Water Management District (SJRWMD) to buy the land, with Natural Resource Conservation Service (NRCS) assistance, from the farmers and restore it to wildlife habitat. The SJRWMD purchased 13,000 acres of farmland in the fall of 1998. By that time, the fields had been flooded with 1-3 feet of water for several months. The Service was notified of bird mortalities in January 1999; it was reported that more than 100 American white pelicans and eight wood storks (a Federally listed endangered species) had died. To date, more than 500 birds (including more than 60 wood storks) have died at this site and an additional 450 dead birds have been collected from nearby locations. In several cases, birds were described as "falling from the sky."
Service contaminants staff are still in the process of investigating the situation to identify all sources of the contamination. Birds are still dying, and the survivors may not be successfully reproducing. Contaminants staff also are working with the SJRWMD, NRCS, the Florida Department of Natural Resources, the Florida Audubon Society, and a myriad of scientists and agencies to determine what management steps are needed to eliminate further exposures of birds to contaminants at the site.