The National Oceanic and Atmospheric Administration issued a study Thursday that found hazardous materials such as lead and zinc were at low to medium levels for toxicity to shellfish near the reserve defense ships.
The study determined that most of the heavy metals are at concentration levels comparable to other parts of San Francisco Bay, which has been compromised by years of pollution from urban runoff, factories, sewage plants and shipping.
Rob Ricker, a NOAA regional manager, said that flaking paint from the 70 or so decommissioned ships of the National Defense Reserve Fleet was the most likely source of heavy metals and other toxic chemicals found in bay sediments in close proximity to the mothballed fleet. The paint often contains lead, zinc, copper and other toxic materials such as PCBs.
“You can see paint blowing off the vessels,” Ricker said. "As the paint goes into the water and with the break down of the paint, you have a release of heavy metals."