ARCUS | Arctic Research Consortium of the United States

6th Annual ARCUS Award for Arctic Research Excellence


Submitted by   Switgard Duesterloh
Authors   Switgard Duesterloh, J.W. Short, and M.G. Barron
Category   Life Science
Title   Photoenhanced Toxicity of Weathered Alaska North Slope Crude Oil to Two Species of Marine Calanoid Zooplankton
Affiliation   Juneau Center School of Fisheries and Ocean Sciences, University of Alaska Juneau, Juneau, AK, USA

Abstract

This study investigated the synergistic toxicity of polyaromatic compounds (PAC) in oil and ultraviolet radiation (UV) in natural sunlight to the calanoid copepods Calanus marshallae and Metridia okhotensis. These copepods were first exposed to low doses (-2µg total PACIL) of the water-soluble fraction of weathered Alaska North Slope (ANS) crude oil for 24 hours and subsequently to low or high levels of natural sunlight. Responses included mortality, impairment of swimming ability and discoloration of lipid sacs. There was 80 to 100% mortality and morbidity of C. marshallae exposed to UV and oil, compared to less than 10% effect in oil only or UV only treatments. In M. okhotensis 100% mortality occurred in the UV and oil treatment, 43% mortality and 27% morbidity in the UV only treatment, and less than 5% effect in the oil only treatment. The interaction of the bioaccumulated polyaromatic compounds (PAC) and ultraviolet (UV) radiation was highly significant (P