April 13, 2014
The bay of San Francisco is being investigated by scientists that claim the clams found in the bay show a high level of toxicity, and could be causing the bay to be a dead zone for both sea creatures and humans.
MENLO PARK (KCBS) — California’s ongoing drought is affecting much more than just drinking water supplies as scientists are looking into how declining rainfall may be increasing the toxicity of the San Francisco Bay.
With less water flowing into the bay during the drought, there is an increase in naturally occurring toxins—materials which are then ingested by all kinds of creatures, including the overbite clams, which are non-native to the ecosystem, and then move up the food chain.
“Diving ducks love this clam. It’s very available for fish, they don’t have fight their way through the shell,” scientist Jan Thompson said, who along with her colleague Robin Stewart, are studying the clams at the U.S. Geological Survey in Menlo Park.
They want to determine how many toxins are getting into the clams and into the Bay during the drought. They are especially looking for high levels of selenium.
“We’re looking for what are the potential risks, particularly as contaminates are concerned, for not only the food web and species that we’re interested in but also for human consumption,” Stewart said.
The results of the USGS study are expected to be completed later this year.