On the feasibility of effects monitoring

This report first discusses selected recent literature on the effects of pollutants on marine organisms under six headings - biochemical, morphological, physiological, behavioural, population/community and genetic, and examines the ways in which these effects are measured experimentally, including the use of bioassay procedures. It then goes on to consider effects in the light of their potential value in monitoring programmes. While some symptoms could probably be measured in the sea, there would in most cases be great difficulty in recognising them as effects of specific pollutants, and in distinguishing pollution - linked from naturally-caused events. This is particularly so in population and community studies and the difficulty in using population-related observations is discussed. Most behavioural and genetic effects also seem difficult to apply at present in a monitoring context. However certain biochemical, morphological and physiological effects measured on individuals may be useful, and bioassay procedures are pertinent. 

The relevance of existing effects data to current baseline and monitoring program.mes is discussed, and it is concluded that effects and monitoring studies cannot easily be linked at present, because whereas monitoring programmes tend to provide information on residues in organisms, most effects studies relate effects to environmental concentrations of contaminants. There is an urgent need to link environmental concentrations, body burdens and effects.

In spite of the difficulties it is considered that a start should be made in assessing the possibility of effects monitoring, and the following four-part approach is suggested.

1. An attempt could be made to build up a picture of the well-being of organisms in various geographical areas, and as a start observa-tions on some or all of the following items could be included in on-going biological survey programmes: liver/somatic and gonad/somatic indices; vertebral deformities; tumours, lesions, etc.; gill damage; general morphology.
2. Since some of the best monitoring data, currently available refer to residues in organisms, it is suggested that experiments should be conducted to link effects with residues, as well as with levels in the water or sediment, and that monitoring programmes should be designed to include relevant tissues or organs.
3. Suitable bioassay techniques should be adapted from the wide range of procedures available, to identify regions of poor water quality and to provide a test of the applicability of experimental results to field situations.
4. A number of effects are recognised as potentially useful in monitoring, but none is thought to be sufficiently understood at present to justify its immediate addition to monitoring programmes. It is suggested, however, that any promising approach identified should be subjected to a concentrated research effort (ideally linked via field validation trials to on-going research programmes) to evaluate its use as a monitoring tool. Among possible topics for such study, scope for growth, gill damage, lysosomal enzymes and steroid metabolism are particularly discussed in the report, but the list is far from exclusive.

These proposals recognise that for adequate effects monitoring no single procedure will be sufficient in itself, but it is felt that the work outlined above could lead in the short term to a closer association between the chemical and biological data that together are necessary for the identification of areas at risk from pollution, and in the longer term to a suite of techniques for the detection, measurement and evaluation of effects in the field.