Could pollution in the St. Johns River be leading to bird deaths?

In adddition to the more than 70 calls that have been made to the St. Johns River fish-kill hotline with reports of dead fish, area organizations have started getting calls to report another ailing species: birds.

On June 8, a bald eagle was found dead beneath Jacksonville’s Fuller Warren Bridge. Workers at Jacksonville’s BEAKS (Bird Emergency Aid and Kare Sanctuary) had received a call about an ailing bald eagle two days prior, and tracked it for over an hour in the water and then later on land. They eventually ceased following the bird after it made its way to a tree, a decision that B.E.A.K.S. founder Cindy Mosley says she now regrets.

Though Mosley can’t say for certain whether the sick eagle and the dead eagle found days later were the same, she is quick to point out that it wasn’t a solitary case: “We’ve gotten calls for around 10 dying or dead ospreys in the past month. There were a few in Putnam County — one that died near Lake George and at least three or four that were sent to us in Jacksonville. Most of them died almost immediately and one survived for just two days after we got him. We have sent some bodies to the Game Commission for testing. We don’t know definitively what the problem is, but they seem to be either coated with something that is hindering them from flying, or they are having trouble preening themselves. They couldn’t dry themselves off. And a wet bird is a dead bird.”

Joy Hill, of the Florida Fish and Wildlife Conservation Commission, says that eagle bodies are treated differently than other animals: ”The Florida Fish and Wildlife Commission collected the body, but it was taken to an eagle repository in Colorado, where its body will be disassembled for use in Native American religious ceremonies.” Though the eagle body was never tested for any chemicals, two of the dead ospreys were necropsied, albeit with inconclusive results.

Dan Wolf, a biologist with the FFWC, says that he saw no major physical abnormalities in the ospreys he studied, but did note that they were likely very hungry: “They seemed relatively normal, but they had empty stomachs. They clearly hadn’t eaten in awhile.”

An osprey’s diet almost exclusively consists of live fish, which, due to recent algal blooms in the St. Johns River, are increasingly harder to find. And though it seems that a dead fish would be an ideal meal for a pescaterian bird, Wolf says ospreys are “opportunistic eaters” that  likely wouldn’t eat a dead fish: “It’s possible that they could eat a sick fish that was flailing on the surface of the water, and that would lead to a sick bird.”

Even worse than eating a sick fish would be ingesting a toxin not unlike those that come about during occurences of algal blooms — blooms that are the main culprit in the river fish kill. Avian botulism occurs when decomposing vegetation and invertebrates combines with warm temperatures, producing toxins. Botulism requires an environment to be lacking in oxygen, not unlike the anaerobic condition created when algae decays. With recent conditions in the St. Johns ideal for the paralytic disease, it comes as no surprise that river-dwelling birds like the osprey are turning up dead.

Wolf says that algal blooms like those that have been recently reported can lead to bird deaths, but further studies need to be done to come to any sort of definitive conclusion. Though he is in possession of several algal samples, the recent gulf oil spill has made it difficult to focus on testing: “Testing will be done eventually; it’s just a matter of time.”

Since the dead fish were first reported (around Memorial Day) thousands more have surfaced, a problem which is not only aesthetically displeasing, but quite dangerous. The Duval County Health Department recently issued a health advisory for all areas affected by the fish kills, advising residents to use “common-sense precautions and to avoid algae blooms and fish kill areas.”