Navigation Links
Fecal microorganisms inhabit sandy beaches of Florida

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.

All the feces-derived bacteria (i.e. traditional indicators of sewage contamination) were capable of enhanced survival in sand and, more importantly, were capable of growth in the sand leading to much higher numbers. Conversely, in seawater the bacteria steadily decreased in number over time. Results also showed a rapid drop off in bacterial numbers in bathing water sampled close to the sand compared with 5, 10 or 20 m from shore. This indicates that the shoreline water is affected by bacterial run-off from the sand.

This has implications for beach managers since the number of bacteria from feces (fecal bacteria) in the water is used to assess the presence of sewages. A high count of these indicator bacteria would require the beach to be closed, an action with financial consequences in tourist rich regions such as Florida. Any bacteria washed from the sand complicates the interpretation of counts in the water and could lead to unnecessary beach closures. On the other hand, high numbers of fecal-derived bacteria growing in the sand could constitute an increased health risk.

The authors suggest that water quality managers should consider sampling water further from shore than is routinely practiced (say 10 m from the swash zone) to avoid the complications of bacteria being washed from sand. However, further studies are required to determine whether these higher counts pose a health hazard to bathers. The results of a beach questionnaire designed to look for incidences of illness after beach use were inconclusive.


Contact: Sara Uttech
Soil Science Society of America

Related biology news :

1. Research team finds that microorganisms filter nitrogen from small streams
2. Palm Beach County wants to establish a Max Planck Institute in Florida
3. New south Florida nursery to focus on staghorn corals
4. ASNTR 15th anniversary meeting to be held May 1-3 in Florida
5. DHS Expands Biometrics-at-Sea Program to the Florida Straits
Post Your Comments:
(Date:6/14/2017)... -- IBM (NYSE: IBM ) is introducing several innovative partner ... developing collaboration between startups and global businesses, taking place in ... event, nine startups will showcase the solutions they have built ... France is one of ... 30 percent increase in the number of startups created between ...
(Date:5/6/2017)... , May 5, 2017 ... just announced a new breakthrough in biometric authentication ... exploits quantum mechanical properties to perform biometric authentication. These ... smart semiconductor material created by Ram Group and ... finance, entertainment, transportation, supply chains and security. Ram ...
(Date:4/17/2017)... , April 17, 2017 NXT-ID, Inc. (NASDAQ: ... announces the filing of its 2016 Annual Report on Form 10-K ... Commission. ... 10-K is available in the Investor Relations section of the Company,s ... the SEC,s website at . 2016 Year ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... ... Disappearing forests and increased emissions are the main causes of the evolving air ... living in larger cities are affected by air pollution related diseases. , That is ... globally - decided to take action. , “I knew I had to take action ...
(Date:10/10/2017)... ... 2017 , ... San Diego-based team building and cooking events company, Lajollacooks4u, has ... The bold new look is part of a transformation to increase awareness, appeal to ... period. , It will also expand its service offering from its signature gourmet cooking ...
(Date:10/10/2017)... Poway, California (PRWEB) , ... October 10, 2017 , ... ... afternoon speaking at his local San Diego Rotary Club. The event ... San Diego, CA and had 300+ attendees. Dr. Harman, DVM, MPVM was joined ...
(Date:10/10/2017)... ... October 10, 2017 , ... ... process optimization firm for the life sciences and healthcare industries, announces a presentation ... San Francisco. , The presentation, “Automating GxP Validation for Agile Cloud Platforms,” will ...
Breaking Biology Technology: