New Zealand Journal of Marine and Freshwater Research abstracts

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Comparison of the sensitivity to heavy metals and pentachlorophenol of the mayflies Deleatidium spp. and the cladoceran Daphnia magna

CHRISTOPHER W. HICKEY MAGGIE L.VICKERS

Water Quality Centre
DSIR Marine and Freshwater
Department of Scientific and Industrial Research
P. O. Box 11115, Hamilton, New Zealand

Abstract A laboratory testing protocol has been established for the mayfly Deleatidium spp. This involves incubation of organisms for 96 h at 15°C with continuous aeration. Under these conditions EC50 concentrations for Deleatidium were similar to those for the cladoceran Daphnia magna (48 h test) for four heavy metal toxicants (Cd²⁺, Cr⁶*, Cu²⁺, and Zn²⁺) and one organic compound (pentachlorophenol). TheECso concentration forZrr⁺ was, however, markedly higher for Deleatidium, indicating lower sensitivity. Deleatidium showed a strong increase in sensitivity with increasing exposure time, suggesting that the organism may be relatively insensitive to short-term (< 24 h) elevations in heavy-metal concentrations. Comparison with published data for other riverine invertebrates and fish suggests that Deleatidium is among the more sensitive species.

Keywords Deleatidium; mayflies; heavy metals; cladocerans; toxicity; water quality

New Zealand Journal of Marine and Freshwater Research, 1992, Vol. 26: The Royal Society of New Zealand 1992
Received 16 August 1991; accepted 16 January 1992

PDF file of entire paper: medium quality (589K); (scanned from paper original: notes about this process)

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