Adding mussel to environmental assessments.Researchers have developed a new way to use mussel mussel, edible freshwater or marine bivalve mollusk. Mussels are able to move slowly by means of the muscular foot. They feed and breathe by filtering water through extensible tubes called siphons; a large mussel filters 10 gal (38 liters) of water per day. shells to diagnose a sick environment.
While alive, mussels incorporate metals from the environment into their shells, which can then serve as enduring chemical snapshots of environmental conditions.
To see whether mussel shells tell an accurate ecological story, Megan E. Brown of Virginia Tech in Blacksburg and her colleagues focused on a well-documented ease of environmental contamination.
They collected 366 mussel shells from five sites along the North Fork North Fork, river, c.100 mi (160 km) long, rising in the Ozarks, S Mo., and flowing S, into N Ark., to the White River. Near its mouth is Norfolk Dam (completed 1944), which impounds Norfolk Lake and has a power plant. Holston River For other uses of "Holston", see Holston (disambiguation).
The Holston River is a major river system of southwestern Virginia and East Tennessee. The three major forks of the Holston (its North, Middle and South Forks in Virginia. Three sites were downstream and two were upstream of a factory that emitted mercury into the river between 1950 and 1972. As early as 1957, mussel populations in the river began dying out.
In shells that the USGS USGS United States Geological Survey (US Department of the Interior) team harvested just downstream of the factory, mercury concentrations ranged up to 4,637 micrograms per kilogram kilogram, abbr. kg, fundamental unit of mass in the metric system, defined as the mass of the International Prototype Kilogram, a platinum-iridium cylinder kept at Sèvres, France, near Paris. ([micro]g/kg). The upper reading for shells upstream was 31 [micro]g/kg. Shells farther downstream from the plant topped out at 115 [micro]g/kg. Museum specimens of shells collected from the river before the factory existed showed mercury concentrations of about 6 [micro]g/kg.
Although river currents often damage or move shells, mussel remains can reveal the history of local environmental contamination, the researchers conclude in an upcoming Environmental Science and Technology.--B.H.