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Title: Availability of sediment-bound cobalt, silver, and zinc to a deposit-feeding clam. [Macoma balthica]

Conference ·
OSTI ID:7345162

The availability to Macoma balthica of sediment-bound metals was dependent upon the physical-chemical nature of the metal-sediment association. Laboratory studies of bioaccumulation from individual sedimentary trace-element sinks labelled with radioactive tracers of Ag, Co and Zn indicated bioavailability varied among metals within a given sink and among sinks for a given metal. Little bioaccumulation was observed from several sinks which may be common in nature, e.g., little Zn or Co uptake was observed when those metals were coprecipitated with amorphic iron oxide or manganese oxide. However, Ag, Co, and Zn were all taken up from detrital organics and Ag was accumulated by the clam from the iron oxide precipitate. Even quantitatively minor sinks within aquatic sediments may be important sources of some metals for M. balthica. Uptake rates of Co and Zn from biogenic carbonates (crushed clam shells) were significantly greater than rates of uptake from other sinks. Likewise, Ag uptake from both biogenic carbonates and synthetic calcites was greater than Ag uptake from iron oxides or detrital organics. Sinks from which bioaccumulation of bound metals was greatest also showed the greatest rate of sediment to water desorption of metals. Where such sinks are abundant in nature, bioavailability of sediment-bound metals may be enhanced both through increased uptake from ingested particulates by deposit feeders, and through increased sedimentary desorption, resulting in higher concentrations of solute metals.

Research Organization:
Geological Survey, Menlo Park, Calif. (USA)
OSTI ID:
7345162
Report Number(s):
CONF-750929-4
Resource Relation:
Conference: 15. symposium on the biological implications of metals in the environment, Richland, WA, USA, 29 Sep 1975
Country of Publication:
United States
Language:
English