Bivalve Monitoring: Figure 4.14

Tables

Figure 4.14. Total DDT concentrations in parts per billion dry weight (ppb) in three transplanted bivalve species at 15 RMP stations during the wet- and dry-season sampling periods. There were no samples for Yerba Buena Island (BC10), Red Rock (BC60), Petaluma River (BD15), and Davis Point (BD40) in the wet season due to zero percent species survival. Petaluma River (BD15) also had zero percent survival in the dry season. Bivalves were not deployed at Grizzly Bay (BF20) in the dry season due to a lack of species from a "clean" source. T-0 (time zero) is the initial concentration before deployment in the Estuary. T-0 values are missing for C. fluminea for the dry season because the population at Lake Chabot crashed before sampling. Accumulation factors ranged from 2.0 in the wet season to 19.9 in the dry season. Median concentrations were highest in C. fluminea, intermediate in C. gigas, and lowest in M. californianus. The highest measured concentration was in C. fluminea, at Sacramento River (BG20) in the dry season.

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