In high-traffic areas, impacts from vessels discharging sewage increase. Pathogens found in untreated sewage can cause extreme illness and even death when ingested by humans. Untreated sewage discharge from vessels can suffocate animals and plants living in the aquatic environment. Delicate coral reef communities and shellfish beds are particularly sensitive to untreated sewage. Fewer shellfish bed closures result in safer and more abundant harvests for consumers.
Shellfish often accumulate contaminants from the environment.
Eating contaminated shellfish, especially when raw or partially cooked, poses considerable health risk to humans. Since the early 1920s the U.S. Public Health Service has been monitoring the nation s shellfish harvest for bacterial contamination. Today the harvest of shellfish is restricted or prohibited in approximately 30 percent of all shellfish growing waters because of poor water quality. Untreated sewage discharge from boats accounts for about 13 percent of those restrictions. Coral reefs are one of the most spectacular and diverse ecosystems on earth.