Infectious stowaways.While in port, shipping vessels often suck huge quantities of water into their ballast tanks A ballast tank is a compartment within a boat or ship, that holds water. A vessel may have a single ballast tank near its center or multiple ballast tanks typically on either side. to replace the stabilizing weight of cargo they've off-loaded. Along with this water comes abundant aquatic life, such as mussels and crabs, which journey with the ships--often crossing entire oceans--until the ballast bal·last n. 1. Heavy material that is placed in the hold of a ship or the gondola of a balloon to enhance stability. 2. a. Coarse gravel or crushed rock laid to form a bed for roads or railroads. b. is dumped in preparation for loading new goods. Largely ignored in this lively exchange are microbes. A new study finds that releases of ballast water dump huge quantities of bacteria and viruses into ports around the globe. Gregory M. Ruiz of the Smithsonian Environmental Research Center The Smithsonian Environmental Research Center (SERC) is a 2,800-acre environmental research and educational facility operated by the Smithsonian Institution located in Edgewater, MD on the Rhode and West Rivers. in Edgewater, Md., and his colleagues sampled ballast water from 15 ships entering the Chesapeake Bay Chesapeake Bay, inlet of the Atlantic Ocean, c.200 mi (320 km) long, from 3 to 30 mi (4.8–48 km) wide, and 3,237 sq mi (8,384 sq km), separating the Delmarva Peninsula from mainland Maryland. and Virginia. . In the Nov. 2 NATURE, they report an average of 830 million bacteria and 7.4 billion viruses in each liter of water. Though most of the microbial microbial pertaining to or emanating from a microbe. microbial digestion the breakdown of organic material, especially feedstuffs, by microbial organisms. vagabonds have yet to be identified, Ruiz' team did find in every sample at least one of the two bacterial strains that can cause epidemic cholera Noun 1. epidemic cholera - an acute intestinal infection caused by ingestion of contaminated water or food Asiatic cholera, cholera, Indian cholera infectious disease - a disease transmitted only by a specific kind of contact . Though other studies had found microbes in ballast, Ruiz says that his study was the first to quantify them and to assay for those that were in a resting phase but able to reproduce when conditions turned favorable. The new data also indicate that, counter to previous studies, most of the cholera bacteria were not attached to fine debris in the water. That's potentially bad news, Ruiz explains, because it suggests that filters won't work as a removal strategy for these potentially deadly microbes. |
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