Featured Research

from universities, journals, and other organizations

Fecal Microorganisms Inhabit Sandy Beaches Of Florida

Date:
May 14, 2008
Source:
Soil Science Society of America
Summary:
A study of Florida beaches has shown that wet sand and dry sand above the intertidal zone have significantly more fecal bacteria than near-shore seawater. Scientists researched whether indicator bacteria survive longer in sand relative to open water and found that all feces-derived bacteria were capable of enhanced growth and survival in sand, while in seawater the bacterial populations steadily decreased over time.

Early results of a study of Florida beach sand found that wet sand (in the intertidal zone) and dry sand above the intertidal zone had significantly more fecal bacteria than near-shore seawater.
Credit: iStockphoto/Ben Russell

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.


Story Source:

The above story is based on materials provided by Soil Science Society of America. Note: Materials may be edited for content and length.


Cite This Page:

Soil Science Society of America. "Fecal Microorganisms Inhabit Sandy Beaches Of Florida." ScienceDaily. ScienceDaily, 14 May 2008. <www.sciencedaily.com/releases/2008/05/080513101555.htm>.
Soil Science Society of America. (2008, May 14). Fecal Microorganisms Inhabit Sandy Beaches Of Florida. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2008/05/080513101555.htm
Soil Science Society of America. "Fecal Microorganisms Inhabit Sandy Beaches Of Florida." ScienceDaily. www.sciencedaily.com/releases/2008/05/080513101555.htm (accessed October 2, 2014).

Share This



More Plants & Animals News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Dolphins and Turtles Under Threat in Pakistan

Dolphins and Turtles Under Threat in Pakistan

AFP (Oct. 2, 2014) — The turtles and Dolphins of Pakistan's Indus river - both protected by law - are in a fight for their survival as man's activities threatens their futures. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
'Harvest Break' Endures in Maine Potato Fields

'Harvest Break' Endures in Maine Potato Fields

AP (Oct. 2, 2014) — Educators and farmers are clinging to a tradition aimed at giving farmers much-needed help in getting potatoes out of the fields and into storage before the ground freezes in the nation's northeast corner. (Oct. 2) Video provided by AP
Powered by NewsLook.com
Attacking Superbugs

Attacking Superbugs

Ivanhoe (Oct. 1, 2014) — Two weapons hospitals can use to attack superbugs. Scientists in Ireland created a new gel resistant to superbugs, and a robot that can disinfect a room in minutes. Video provided by Ivanhoe
Powered by NewsLook.com
Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins