Shellfish are filter feeders that eat tiny food particles filtered through their gills into their stomachs, along with bacteria from sewage. Shellfish can convey nearly all waterborne pathogens, including hepatitis, typhoid and cholera to humans. Shellfish beds are closed when the coliform count reaches 14 per 100 ml of water. Public beaches are closed to swimmers when the coliform count reaches 200 per 100 ml of water. In January and February 1995, the Journal of the American Medical Association reported that outbreaks of viral gastroenteritis in Florida, Georgia and Texas, resulting from the consumption of raw oysters, was traceable to marine sewage disposal on or near oyster harvesting areas in Apalachicola and Galveston Bays.
Studies also show the possibility of viral transmission in cooked oysters.
The Clean Vessel Act provides a portion of its total funding for educational outreach regarding the effects of boater sewage and the means by which boaters can avoid improper sewage disposal. The first goal is to make boaters aware of the importance of proper sewage disposal. The awareness campaign kicked off at the February 1996 Miami Boat Show. The kickoff included representatives from the Department of Interior, U.S. Fish and Wildlife Service, Environmental Protection Agency, NOAA, U.S. Coast Guard, Florida Department of Environmental Protection, and the National Marine Manufacturers Association. These agencies continue to work with marine interests to distribute materials and educate boaters on the use of pumpout and portable toilet dump stations.