Assessing the toxicity of chemically fractionated Hamilton Harbour (Lake Ontario) sediment using selected aquatic organisms

Abstract

Studies of the sediments of Hamilton Harbour, Lake Ontario, Canada, have shown variable degrees of pollution with a large number of organic and inorganic pollutants. Three areas in the Harbour -Windemere Basin, Cootes Paradise and Randle Reef -exhibited particularly high levels of contaminants, with concomitant impacts on benthic organisms. Sediment samples examined in this study were taken from a site in Randle Reef in Hamilton Harbour and a station (LE 23) in Lake Erie used as a reference sample. The samples were subjected to chemical fractionation to remove organic contaminants, with one fraction being used as total extract, and another aliquot being subjected to silica gel fractionation to give four fractions. Each fraction was chemically analysed and an aliquot used for bioassays following exchange with dimethylsulfoxide. Standard biotests were performed with Daphnia magna, Hyalella azteca, Pimephales promelas (fathead minnows) and Selenastrum capricornutum . Results from direct sediment contact bioassays indicated that sediment from Randle Reef is highly toxic, whereas the Lake Erie sample had no observable impacts. Total extract when added at 1% to the bioassays replicated the solid phase with acute toxicity for Randle Reef, and no effect on Lake Erie. For the silica gel fractionation, Fraction 1 (F1) showed similar toxicity as the total extract, even at low additions, whereas F2-4 gave variable and inconclusive results. F1 eluted with hexane contained the non-polar fractions, predominantly the polyaromatic hydrocarbons, and these compounds are the most likely causative agents for the highly acute toxicity observed in the sediment of Randle Reef.

The utilization of the freshwater invertebrates hyalella azteca and daphnia magna for use in assessing potential endocrine distruption in aquatic systems

“…Hyalella azteca are freshwater amphipods extensively used to test acute and chronic toxicity of aquatic contaminants, especially in sediment toxicology testing due to their close association with sediments (Nebeker et al, 1986;Mackie, 1989;Borgmann et al, 1991;Phipps et al, 1995;McCarthy et al 2004;Wang et al, 2004;Ingersoll et al, 2005). An added benefit to using Hyalella is that they are prolific and rather hardy; thus, they are easy to culture and their results also generate less false positives than Daphnia.…”

Lake and Reservoir Management

“…Toxicity of chemically fractionated Hamilton Harbor (Lake Ontario, Canada) sediment using selected aquatic organisms was assessed (McCarthy et al, 2004). In another study, increases in sediment loads on aquatic ecosystems were shown to have implications for the conservation of littoral communities in sediment-impacted areas (Donohue and Irvine, 2004a).…”

Contaminant concentrations and biomarkers in 21-day old Herring Gulls (Larus argentatus) and Double-crested Cormorants (Phalacrocorax auritus) from eastern Lake Ontario, and from Hamilton Harbour in western Lake Ontario in 1989 and 1990

“…High levels of contaminants in the sediment have also been associated with the restricted benthic macroinvertebrate community of the harbour (Krantzberg and Boyd, 1992). Polyaromatic hydrocarbons in Hamilton Harbour sediment were the cause of toxicity to four aquatic species in bioassays (McCarthy et al, 2004). However, persistent organic pollutant concentrations in the Great Lakes declined precipitously in the late 1970s, and, at a slower rate, have continued to stabilize or decline since that time (Pettit et al, 1994).…”