The goal of this study is to describe the variation of metal concentrations in the environment of San Diego Bay, California, and assess the biological availability of metals throughout the Bay considering the local environmental characteristics. The concentrations of 15 metals were measured from sediment (top layer) and seawater particulates collected during an 8 week period from June 14 to August 9, 2001 at four sites in San Diego Bay, located near navigation buoys R8 (site A), R16A (site B), G1 (site C) and R34 (site D). Metals were also measured from tissues of the common brittlestar, Ophiothrix spiculata (Ophiuroidea, Echinodermata), transplanted from outside to inside the Bay. Experiments with transplants determined the ratio of metal from the environment that is biologically available to fauna. Measuring metal concentrations from disk and arm tissue of transplanted brittlestars determined the variation with time of metal contamination from the diet and/or from the seawater. Indeed, brittlestars can accumulate metals by feeding on metal contaminated food items that will mainly target the disk tissue, while they can also accumulate metals directly from seawater in arm tissue. The report also includes, from each site, environmental parameters such as surface and bottom temperature, salinity, turbidity and tidal height.