Fecal microorganisms inhabit sandy beaches of Florida

From a press release issued by the Soil Science Society of America:

MADISON, WI, MAY 12, 2008 -- Traditionally, the cleanliness of a beach is monitored by sampling the bathing water a few meters from shore. But since sand is an effective filter, it follows that fecal bacteria (those from sewage) may be concentrated in the sand as the tide flows and ebbs. Moreover, trapped bacteria are offered a large surface area for attachment, nourishment from nutrients in sand crevices, and protection from sunlight. These bacteria might be afforded greater survival opportunities and may even be nourished enough to replicate in the beach environment. Dr. Andrew Rogerson, formally of the Oceanographic Center of Nova Southeastern University, Florida, headed an Environmental Protection Agency study to determine the levels of fecal-derived bacteria in Florida beach sand and look for health implications. Early results showed that wet sand (in the intertidal zone) and dry sand above the intertidal zone had significantly more fecal bacteria than near-shore seawater. This lead to the question– do indicator bacteria survive longer in sand relative to open water? A series of laboratory experiments were conducted to answer this question and the results are presented in the May-June issue of Journal of Environmental Quality.

The study leads to another question, too. Do heavily used beaches in the Caribbean also harbor fecal bacteria?