Avian botulism is a paralytic disease caused by one of the deadliest toxins known to mankind. It is produced by a naturally occurring bacterium, Clostridium botulinum, and when environmental conditions cause the toxin to accumulate in their food supply, botulism can kill thousands of birds each year. Under a Cooperative Research and Development Agreement, the USGS, through its National Wildlife Health Center Diagnostic Microbiology Laboratory, with support from the Great Lakes Restoration Initiative, is developing a rapid method for detecting a Type E avian botulism that causes mortality in fish-eating birds. This method uses a fluorescence-based bioassay and would potentially eliminate the need to use laboratory animals in mouse lethality assays. The new assay method will also be less labor intensive and faster so it will facilitate analysis of the large number of samples required to conduct meaningful ecological studies. This method may also have applications for human health since Type E botulism can occur in humans following consumption of improperly prepared fish.