FY 1986

Seasonal and vertical variations in the elemental composition of suspended and settling particulate matter in Puget Sound, Washington

Feely, R.A., G.J. Massoth, E.T. Baker, J.F. Gendron, A.J. Paulson, and E.A. Crecelius

Estuar. Coast. Shelf Sci., 22, 215–239, doi: 10.1016/0272-7714(86)90114-9 (1986)

The distributions of C, Al, Si, P, Cr, Mn, Fe, Ni, Cu, Zn and Pb in suspended and settling particulate matter from Puget Sound were studied to investigate the processes affecting the uptake of trace metals by particulate phases. Particulate material was collected by water filtration procedures and sequentially-sampling sediment traps during approximately bimonthly surveys from December 1980 through December 1981 at a station located in the center of the main basin of Puget Sound. The samples were selectively extracted for trace metals associated with oxide, organic, and residual phases and analyzed by graphite furnace atomic absorption spectrophotometry and X-ray energy spectrometry. The results show that for Mn, Fe, Zn and Pb, residual and oxide phases were the most important phases controlling the vertical flux; whereas residual and organic phases controlled the vertical flux of Cu. The average annual flux data were used along with dissolved metal profiles to compute scavenging residence times for several trace metals in Puget Sound. Relatively short scavenging residence times (i.e. <30 days) were calculated for those metals that were significantly enriched in oxide phases, such as Fe, Mn and Pb. In contrast, longer scavenging residence times (>100 days) were calculated for metals enriched in organic phases, such as Cu.