Copper in Lake Pontchartrain bottom sediment: Relationship to sediment properties

Abstract

Several watersheds in the Louisiana Pontchartrain Basin are listed as impaired, with dissolved Cu as one of the impairments. In this study we determine Cu levels in sediment of Lake Pontchartrain (which comprises part of one of the largest estuaries in the Gulf Coast region) which receives water from impaired watersheds. Sediment samples were collected along an 8 km sampling grid (174 sites) and analyzed for total Cu in sediment. The average Cu content in sediment was 13.6 ± 6.7 mg.kg−1 ranging from 0 to 31.5 mg.kg−1 (n = 174). Results show that there was little Cu pollution in the lake sediment. Cu level was correlated with Al content (r = 0.888**) and Fe content (r = 0.907**) of sediment. Higher Cu was also found in sediment with high clay content (r = 0.429**). Cu was inversely correlated with sand content of sediment (r = −0.520**).