Scientists study effects of mercury in Bay-Delta birds

Scientists taking blood samples from bird at San Francisco BayThe U.S. Fish and Wildlife Service and the U.S. Geological Survey, with assistance from the San Francisco Bay Bird Observatory, are conducting a variety of studies to assess the impact of mercury on birds in the San Francisco Bay-Delta estuary. Scientists are working both in the field – collecting and sampling adult birds, chicks and eggs – and in the laboratory. One of their goals is to assess whether extensive tidal marsh restoration in the Bay will increase the risk of mercury exposure for wildlife. Locations include:

Caspian terns, with chicksHikers, anglers and others may occasionally see biologists at different locations around the Bay working on this important study. They will be trapping limited numbers of birds. In most cases, they will collect blood samples and release the birds unharmed. To fully understand the effects of mercury on these species, a much smaller number of birds and eggs will be taken to laboratories for in-depth analysis. Overall, only a tiny percentage of birds in the Bay region will be affected by these studies.

The biologists should not cause any disruption to public use of Bay lands. But please, do not enter the areas off the paths where they are working.

Mercury, a highly toxic metal that can cause nervous system and reproductive disorders in wildlife, enters the Bay-Delta Estuary from a number of sources. One of the main sources of mercury in the Estuary is from historic mercury and gold-mining activities.

Among the species we are studying:

For more information, contact Tom Maurer, USFWS, at (916) 414-6590.