Sacramento River and San Joaquin River) San Joaquin River Or Proposed San Luis Drain Extension, Sacramento River
FIGURES Selenium source Organic carbon-enriched sediment deposits Depositional environments Freshwater Seawater Geologic sources Coal Soils and Alluvium Oil Phosphorite Anthropogenic Power Generation Irrigation Refining Mining activity Pollutants Ash, Flue Gas Scrubbing Subsurface drainage Wastewater Tailings, runoff Kesterson NWR, San Francisco Blackfoot San Joaquin River, Receiving waters Belews Lake, Bay-Delta River watershed, (examples) North Carolina Tulare Basin, California Estuary, California Idaho scoter, scaup, coot, duck, grebe Species of bluegill, sunfish, sturgeon, splittail, trout, coot, horse, concern bass, bullhead avocet, stilt, sculpin, splittail, salmon flounder, salmon, sheep, elk, cow Dungeness crab Figure 1. Conceptual model of Se pollution with examples of source deposits, anthropogenic activities, receiving water bodies, and biota at risk. Bay-Delta Selenium Model Composite Source Load ¸ Composite Volume (oil refinery discharges, agricultural drainage via (Sacramento River and San Joaquin River) San Joaquin River or proposed San Luis Drain extension, Sacramento River Composite Freshwater Endmember Concentration (head of estuary) Transformation Phytoplankton, algae, bacteria Dissolved species Partitioning (Kd) suspended particulate material and bed sediment (selenate, selenite, organo-Se) (elemental Se, particulate organo-Se, adsorbed selenite/selenate) bioaccumulation prey clams zooplankton amphipods trophic transfer sturgeon splittail striped bass predators diving ducks flounder splittail effects Impaired reproduction, teratogenesis, selenosis Figure 2. Conceptual model describing linked factors that determine the effects of selenium on ecosystems. The sequence of relations links environmental concentrations to biological effects. The general term “bioaccumulation” can be applied to all of the biological levels of selenium transfer through the food web, but in this report we use the term explicitly in reference to particulate/invertebrate bioaccumulation. 122°30' 122°00' .
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