1. Plymouth Environmental Research Centre
University of Plymouth
England
Brief introduction to the need for biological effects measures in a broad context - What they can give us and then a review of considerations that must be made when seeking to develop these tests. What we need to be aware of.
At PERC we seeking to develop a whole host of biological effects measures to help to better manage the environment. One of these techniques allows us to non-invasively study the heart rate of invertebrate animals. It is this technique that I will concentrate on today and the potential it has for a wider role in education.
Shaw Bamber

2. Biological monitoring What can it offer?
The potential for great sensitivity to environmental stress
Effects reflect integration of exposure history
Biological and ecological relevance
One of the first questions we need to ask is what can such bioassays offer us.
Much of the work we are undertaking at Plymouth is based on sub-lethal, and therefore non-destructive, measurements. Such tests allow us the opportunity to examine the health of animals in exposed marginal habitats, perhaps occurring as a result of pollution, without further reducing the population by destructive sampling.
If changes in the physiological and behavioural patterns of animals can be detected before mortality then there remains the strong possibility that the threshold of sensitivity to exposure to various toxicants can be lowered.
Physiological assays also allow us to view the effects of integrated exposure taking into account possible synergistic and antagonistic factors in the medium.
Careful selection of physiological and behavioural ‘end points’ in assays using animals representative of local populations offers the opportunity for greater biological and ecological relevance to be derived from tests. - what will similar invertebrate animals face in the environment.
In addition, certain toxic compounds will exert characteristic effects of certain animals. If these can be recognised then this could provide a big help in ascertaining the nature and even source of toxicants, in other the generation of particular symptoms - must however be aware of the complexity of most effluents.

3. Key stages in the development of a biological monitoring system
Identification of a suitable biological indicator
Establishing ‘normal’ responses and determining the typical limits of variability
Any proposed biological monitoring system clearly needs a development programme. The one employed for our own project is detailed here. In the first instance suitable animals need to be selected, together with the endpoint which will be the focus of the measurement. The next stage is to assess the extent of natural variability we can expect from this measurement, due to natural physicochemical variability and indeed biological variability. Once typical ‘normal’ responses have been established we can introduce test contaminants into the system to see individual effects and to determine thresholds etc. This is the stage we are currently working at. Once this complete, and if results support it, then further work will continue to establish what constitutes an event and then this will be translated to the field.

4. Natural Physical and Chemical Variables
Biological Variables
Natural Physical and Chemical Variables
Temperature
Salinity
Dissolved oxygen
Emersion
Turbidity
Light
Size
Sex
Season
Age
Health
Fasting
Here is a selection of variables that require investigation. In the left column are natural physical and chemical variables mussels might expect to experience in their typical habitat, or indeed in a biomonitoring situation. Pretty standard stuff. Temp salinity etc. In the right column we see examples of some biological variables, size sex, season etc, equally important aspects that require attention in the design of any system.
It is vital to understand the influence of these factors on heart rate if we are to accurately interpret what the machine is telling us.
In terms of scientific value these studies are as vital as those where animals are exposed to chemicals in the lab or gathered from the field. The assessment of all of these parameters can be easily incorporated into studies carried out in schools. Introducing studnets to the complexity of biology and the rigours of good scientific investigation.