Mercury In River Moves Into Terrestrial Food Chain Through Spiders Fed To Baby Birds
http://www.sciencedaily.com/releases/2008/04/080417175221.htm
Summary: Mercury is one of the world’s most troublesome pollutants. For years, thousands of
bodies of water in North America have been under fish consumption advisory. It was originally
thought that only animals that fed on fish would pass mercury through the food chain but Dan
Cristol at the Institute for Integrated Bird Behaviour Studies at The College of William and Mary
in Virginia has discovered otherwise. In fact, a large terrestrial area around South River in
Virginia, where the study took place, was found to be contaminated with traces of mercury.
Mercury enters the food chain through bacteria that convert it into a more potent form in a
process called methylization. Animals in the highest trophic levels have the highest
concentrations of mercury due to a phenomenon called biomagnification. Although
biomagnifications has been studied immensely, terrestrial animals living near water bodies have
been largely ignored until now. Cristol and his colleagues studied food brought by songbirds to
their young. The birds were found to be eating a large amount of mercury contaminated spiders.
“Spiders are like little tiny wolves, basically, and they’ll bioaccumulate lots of contaminants in
the environment,” states Cristol. “The question that remains is this: How are the spiders getting
their mercury?”
ScienceDaily (Apr. 20, 2008) — Songbirds feeding near the contaminated South River are showing high
levels of mercury, even though they aren’t eating food from the river itself, according to a paper
published by William and Mary researchers in the journal Science.....