Estimation of Trace Metal Storage in Lake St. Clair Post-Settlement Sediments Using Composite Samples

Abstract

Sediment cores were collected from 36 stations in Lake St. Clair during 1985 by divers. Usually within hours of collection, replicate cores were extruded and sectioned into 1-to 2-cm intervals. One replicate was stored by Canada Centre for Inland Waters personnel for organic contaminant, mercury, and major element analyses. The other replicate was stored by Great Lakes Research Division and Great Lakes Environmental Research Laboratory personnel for Cs-137, Pb-210, grain size, total carbon, and trace metal analyses. In order to estimate the mass of trace metals stored in the lake sediments, equal mass sections of each core were composited. These and individual sections of each core were analyzed and the total mass and anthropogenic mass of each metal in culturally impacted sediments were calculated. Estimated total and anthropogenic masses (metric tons) are: bismuth, 27 and 13; cadmium, 690 and 440; chromium, 5,100 and 1,800; copper, 3,000 and 1,500; nickel, 4,000 and 1,300; lead, 3,200 and 1,500; antimony, 25 and 13; and zinc, 11,000 and 3,300.