The toxic mercury menace in San Francisco Bay

It’s been long known that mercury from old mines leaks into the San Francisco Bay from the hills above San Jose where the New Almaden Quicksilver Mine operated for more than 120 years before it was shut down in the 1970s. Gold mining also washed mercury, a potent neurotoxin, into tributaries to the bay where it ultimately contaminated the estuary’s aquatic life.

Over the past decade, the San Francisco Estuary Institute, an Oakland science center financed in part by businesses that legally discharge treated waste to the bay, has monitored for mercury.