POLLUTION, FORAMINIFERA AND REMEDIATION OF A SAN FRANCISCO BAY MARSH

San Francisco Bay is one of the most degraded urban marine environments in the nation. Among other things it has lost 90% of its marshes and many of the remaining ones are polluted or endangered. A marsh in Richmond, a highly industrialized city on the east side of the Bay, serves as a model for the effects of pollution and remediation methodology. It contains metals, PCBs, DDT, and acid wastes that came from former munitions, paint and perhaps other manufacturing plants in the 20th century. Metal pollutants include As, Cd, Cu, Pb, Hg, Se, and Zn, ranging from 1 to 22000 parts per million depending on the location and metal. Most of these and the sulfuric acid come from roasted pyrite ore dumped onto the marsh during munitions manufacture. Foraminifera nevertheless florish on the marsh in all parts except those with high metal contamination and very low pH (~2). Species include Trochammina inflata, Miliammina fusca and Haplophragmoides manilaensis. Other species have not been observed. H. manilaensis and M. fusca increase in abundance closer to highly polluted areas although this may be due to more freshwater runoff. Deformed foraminifera occur in samples with high levels of pollution. The marsh is scheduled for remediation by removal of polluted areas to a depth of about 4 feet and replacement with clean mud from other areas of the Bay. A foraminiferal sampling program will monitor the establishment and development of the remediated marsh.