Sediment toxicity in the Duluth-Superior Harbor: Use of Microtox{reg_sign} and Mutatox{reg_sign} as screening assays
- Minnesota Pollution Control Agency, St. Paul, MN (United States)
- Univ. of South Carolina, Georgetown, SC (United States). Baruch Marine Inst.
- Univ. of Minnesota, Duluth, MN (United States). Natural Resources Research Inst.
Sediment toxicity tests were conducted in the Duluth-Superior Harbor at 40 sites as part of an integrated sediment assessment during the fall of 1993. Two rapid assays conducted with Photobacterium phosphoreum (Microtox{reg_sign} and Mutatox{reg_sign}) were compared with three standard US EPA sediment toxicity tests: Hyalella azteca (acute tests) and Chironomus tentans (acute and sub-lethal tests). The response in the two microbial assays was also evaluated for sensitivity to various contaminants analyzed simultaneously in the Duluth-Superior Harbor sediments. Microtox{reg_sign} and Mutatox{reg_sign} were found to be sensitive to approximately one-third and one-half the sediments, respectively; Chironomus tentans was sensitive to 15% of the sediments (either acutely or sub-lethally), while Hyalella azteca was not sensitive to any of the sediments. In almost all cases, Microtox{reg_sign} and Mutatox{reg_sign} correctly identified samples that were toxic to the chironomid, making it useful as a screening tool for toxicity, to reduce the number of sites to be tested with the benthic organisms. The subsequent application of Microtox{reg_sign} as a screen for sediment toxicity in an EMAP survey in the St. Louis River (MN) estuary will be discussed. Correlation of Microtox{reg_sign} and Mutatox{reg_sign} toxicity to environmental contaminants found in the sediments will be presented.
- OSTI ID:
- 242303
- Report Number(s):
- CONF-9511137--; ISBN 1-880611-03-1
- Country of Publication:
- United States
- Language:
- English
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