Marine Environmental Research 28 (1989) 533 545

Abstracts

Towards Effective Application of Ecotoxicology Research Data. B. L. BAYNE. Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth PL1 3DH, Devon, UK.

The growth in ecotoxicology research effort is illustrated by the increased number of papers and posters submitted in this series of PRIMA meetings. This parallels an increase in well-informed concern for the marine environment, and in demands for legislation to protect marine systems. But a wide gulf exists between the research 'base' and the requirements of legislation action. On the one hand are at least five topics of appropriate research interest: the biogeochemistry of contaminants in seawater and sediments; bioaccumulation and modes of toxic action and response: the derivation of standard measures of toxic response; the relevance of these measures to environmental impact; and the criteria for deployment of these measures in field monitoring. On the other hand are end-points of legislation, couched as environmental standards for perceived pollutants and monitored as risk and impact. Four available means for bridging this gulf are considered: protocols for establishing priorities amongst potential pollutants: communication through the research literature; recommended monitoring procedures; and modelling. Relevant scientific requirements, and the relative strengths and weaknesses of present practices, are discussed.

The Use of Mytilus edulis Embryos in Monitoring Changes in Water Quality Associated With the Discharge of Sewage Sludge at a Dispersive Site. RAYMOND BUTLER. Water Research Centre, Medmenham Laboratory, Henley Road, Medmenham, PO Box 16, Marlow, Bucks SL7 2HD, UK.

Mollusc early life history toxicity studies have demonstrated greater sensitivity to a wide range of pollutants than tests using adults of the same species. The degree of developmental success of embryos to D-stage larvae of Mvtilus edulis was used as an indicator of the biological quality of water

533 Marine Environ. Res. (28) (1989) ~ 1990 Elsevier Science Publishers Ltd. England. Printed in Great Britain

534 Abstracts

samples taken in the wake of a sewage sludge disposal vessel. Triplicate water samples were taken from a research vessel drifting in the centre of a sewage sludge slick before, during, and regularly over a period of 1 h after discharge of sludge. A logarithmic dilution series, in reference seawater, of a 1:9 extract of the sewage sludge was tested in parallel to the water samples so that environmental effects could be related to the effects of known sludge concentrations. Each sample was filtered to 0.45/~m and 16-32 cell embryos were inoculated into triplicate 30 ml aliquots of these water samples at a density of approximately 20 embryos per ml. After 48 h incubation at 2 0 C the larvae were preserved with buffered formaldehyde for subsequent microscopic analysis. Successful development was assessed in terms of the mean percentage of larvae reaching the D-stage for each sludge dilution. The 48h median effective concentration (ECso) for the sewage sludge was determined as 0" 17% sludge in reference seawater. A dilution of 1:1000 had no significant (P > 0"05) effect on embryo development; this dilution is approximately that achieved at the disposal ground within 8rain of discharge. Water samples collected immediately before and 8min after dumping caused no significant (P > 0.05) reduction in embryo development compared to embryos cultured in reference seawater.

Effects of Sublethal Concentrations of Cadmium on Oxygen Uptake in Early Stages of Artemia, J. DEL RAMO, A TORREBLANCA, J. ARNAU & J. DIAZ-MAYANS. Laboratoo, ofAnimal Physiology, Department o[ Animal Biology, Faculty ~?[ Biological Sciences, UniversiO, ~[" Valencia, Dr Moliner 50. 46100, Burjassot, Valencia, Spain.

Respiration represents an important physiological index in animals because it reflects the metabolism of an organism. The oxygen uptake rate has been used as an adequate response to pollutant exposure in fish and invertebrates. Cadmium is one of the most representative heavy metals that contaminate the marine environment. The effect of several sublethal concentrations of cadmium (CdCI2) on the oxygen consumption in early stages of Artemia was studied.

GSLi strain of Artemia was used. One day after hatching, the individuals were exposed at 0"5, 2 and 10mgCd/litre. After 3, 7, 9 and 11 days of exposure a sample of each set was obtained and the oxygen uptake was measured by means ofa Gilson differential respirometer. After 3 and 7 days of exposure (animals corresponding to nauplius and metanauplius stage, respectively) the oxygen uptake decreased with increasing cadmium concentration. However, after long exposure periods (11 days) an increase of oxygen uptake in animals exposed to low concentrations of cadmium [0"5 mgCd/litre) with respect to the control was observed, whereas the