Abstract:
As summer months approach, excitement for the warm sun and water trigger
families to solidify plans for a trip to the beach. Parents worry about packing for the
kids, affording travel expenses, finding lodging, and making sure there is enough
sunscreen for everyone. Does anyone ever worry about the condition of the ocean water
they will be swimming in? In America, the Environmental Protection Agency monitors
the health of coastal recreational waters and has the authority to close beaches that do not
meet their safety standards.
Bodies of water may contain pathogenic bacteria, protozoa, and viruses found in
animal waste. These fecal pathogens contaminate our waterways through coastal and
shoreline development, wastewater collection and treatment facilities, septic tanks, urban
runoff, disposal of human waste from boats, bathers themselves, animal feeding
operations, and natural animal sources like wildlife. Humans that swim in these infected
waters risk diseases as mild as ear infections and sore throats, to more serious diseases
such as dysentery, typhoid fever, and Hepatitis A. However, instead of testing for a
variety of diseases, the EPA uses indicator organisms, E. coli and enterococci, to monitor
fecal contamination in coastal recreational waters. If E. coli counts in freshwater rise
above 126 organisms per 100 ml or if Enterococci counts in saltwater rise above 35
organisms per 100ml, a sign posting or beach closure is necessary.
E. coli and Enterococci, referred to as indicator organisms or fecal indicator
bacteria (FIB), are two of the many organisms that live in the intestinal tracks of
mammals and birds. Everyday one human will pass approximately 100 billion to 10
trillion individual E. coli bacteria in their feces. These indicators do not normally harm humans. However, there has been a lot of press about E. coli infecting the public through
food. This particular strain of E.coli, E. coli 0157:H7, is a rare but dangerous strain
which causes hemorrhaging in the intestines.
Because these indicators are relied on so heavily to determine safety of water, it is
imperative to determine if these are suitable indicators, understand the environmental
factors that allow them to thrive, and ways to eliminate them from the waters. Some of
these factors include temperature, light, salinity, rainfall, predation, available nutrients
and environmental pollutants.
