Featured Research

from universities, journals, and other organizations

Microbial Stowaways: Are Ships Spreading Disease?

Date:
May 29, 2008
Source:
Society for General Microbiology
Summary:
Ships are inadvertently carrying trillions of stowaways in the water held in their ballast tanks. When the water is pumped out, invasive species could be released into new environments. Disease-causing microbes could also be released, posing a risk to public health, according to an article in Microbiology Today.

When water held in the ballast tanks of ships is pumped out, disease-causing microbes could be released into new environments, researchers warn.
Credit: iStockphoto/Brian Raisbeck

Ships are inadvertently carrying trillions of stowaways in the water held in their ballast tanks. When the water is pumped out, invasive species could be released into new environments. Disease-causing microbes could also be released, posing a risk to public health, according to an article in the May issue of Microbiology Today.

Related Articles


"There is no romantic adventure or skullduggery at work here," said Professor Fred Dobbs from Old Dominion University, Virginia. Ships pump water in and out of ballast tanks to adjust the waterline and compensate for cargo loading, making the ship run as efficiently as possible. These tanks can hold thousands of tonnes of water. "Any organisms in the water are likely to be released when it is next pumped out."

Many non-native animals and plants have been taken to new environments and become invasive, threatening the survival of local species; some fundamentally alter the ecosystem. Zebra mussels were introduced in North America and the comb jelly in the Black Sea and both have had enormous ecological and economic impacts

For more than 20 years we have known that a variety of large phytoplankton and protozoa are transported in this way, but we know very little about smaller microbes like bacteria and viruses. "It is inevitable that hundreds of trillions of micro-organisms enter a single ship's ballast tank during normal operations," said Professor Dobbs. The majority of these microbes are harmless, but some are a potential risk to public health.

"Vibrio cholerae, which causes cholera in humans, can be carried in ballast tanks," said Professor Dobbs. "There have been no known outbreaks of disease associated with ballasting activities, but the water is only sampled very rarely." Other disease-causing microbes in the tanks include Cryptosporidium parvum and Giardia duodenalis, which cause stomach upsets.

Some people say microbes are present everywhere; they may be easily dispersed because they are so small. However, many experts believe micro-organisms have a "biogeography", a natural home, which means they could become invasive if moved and have a negative effect on different environments. There is some evidence for this argument: two phytoplankton species called diatoms were introduced to the English Channel from the North Pacific Ocean.

The International Maritime Organisation, which sets rules and standards for the global shipping industry, has proposed an upper limit to the numbers of Vibrio cholerae, E. coli, and intestinal enterococci contained in discharged ballast water. A few ships are also using different treatments to reduce and even eliminate the microbes in their ballast water. "A number of techniques are being looked at for this purpose, from filtration to biocides, ultrasound to ultraviolet irradiation," said Professor Dobbs. "Our understanding of the issues involved will increase as more studies are carried out, particularly those employing the tools of modern molecular biology."


Story Source:

The above story is based on materials provided by Society for General Microbiology. Note: Materials may be edited for content and length.


Cite This Page:

Society for General Microbiology. "Microbial Stowaways: Are Ships Spreading Disease?." ScienceDaily. ScienceDaily, 29 May 2008. <www.sciencedaily.com/releases/2008/05/080528191422.htm>.
Society for General Microbiology. (2008, May 29). Microbial Stowaways: Are Ships Spreading Disease?. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/2008/05/080528191422.htm
Society for General Microbiology. "Microbial Stowaways: Are Ships Spreading Disease?." ScienceDaily. www.sciencedaily.com/releases/2008/05/080528191422.htm (accessed October 24, 2014).

Share This



More Earth & Climate News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU Gets Climate Deal, UK PM Gets Knock

EU Gets Climate Deal, UK PM Gets Knock

Reuters - Business Video Online (Oct. 24, 2014) EU leaders achieve a show of unity by striking a compromise deal on carbon emissions. But David Cameron's bid to push back EU budget contributions gets a slap in the face as the European Commission demands an extra 2bn euros. David Pollard reports. Video provided by Reuters
Powered by NewsLook.com
Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Raw: Tornado Rips Roofs in Washington State

Raw: Tornado Rips Roofs in Washington State

AP (Oct. 24, 2014) A rare tornado ripped roofs off buildings, uprooted trees and shattered windows Thursday afternoon in the southwest Washington city of Longview, but there were no reports of injuries. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
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