The Fate of Chemically Dispersed and Untreated Crude Oil in Arctic Benthic Biota

Abstract

Several studies have investigated whether polar or temperate organisms are more sensitive to toxicants. These experiments contain very different outcomes whether a few polar or temperate species are more sensitive to certain toxicants. So far, a comparison of data on all species tested in the two geographical areas is lacking. In this study a comparison is made between both regions to investigate whether polar marine species are more, equally or less sensitive to contaminants, than temperate marine species. Available ecotoxicological data of marine organisms in scientific articles and databases were used. Species Sensitivity Distributions of LC50 and EC50 values were used to compare the sensitivity of species of the two geographical regions for cadmium chloride, crude oil and xylene. For these chemicals sufficient (more than 4) LC50 and EC50 values were available. For six chemicals with less than four toxicity (LC50 or EC50) measurements in polar species: cadmium sulphate, copper chloride, copper sulphate, zinc sulphate, DDT and sodium-dodecyl-sulphate, the available polar data were compared to HC50 values of the temperate species. Logistic means of polar and temperate curves in the SSDs do not differ significantly from each other. This similarity in mean sensitivity indicates that polar marine species are not more sensitive to contaminants than temperate marine species, but equally sensitive. However, the SSDs show several differences between the two regions, for example slopes for polar species are generally steeper than for temperate species. The polar species seem to be more sensitive to xylene than temperate species, because all polar species have a higher PAF than temperate species at the same environmental concentration. There is no quantifiable difference between both regions in sensitivity for xylene, cadmium chloride and crude oil. Very few ecotoxicological data on marine species (LC50 and EC50 values) is available in articles, reports and databases. The more taxiconomical groups are available, the better a comparison can be made of the overall sensitivity between the polar and temperate region.