Coal tar in Hamilton Harbour?Attempts at biological restoration guidelines

Abstract

Sediments in Hamilton Harbour contain extremely high concentrations of polycyclic aromatic hydrocarbons (PAHs) and other contaminants. Two bioassays were used initially to find areas with the worst contamination. Three bioassays were used to develop criteria for cleanup. The bioassays in these sediments yielded the following 50% lethal and 50% effective concentrations for PAHs; Hexagenia 329 μg/g, Daphnia 254 μg/g, and Microtox 89 μg/g. The mean bioassay toxicity was rounded down to 200 μg/g and used to define areas in need of treatment. Simple aspects like oil content, ship traffic, and water depth were also used to prioritize PAH cleanup.