Fish as biomonitors : an integrated perspective

Abstract

There is a perception in some quarters that because there has been a reduction in fish kills in Ireland in recent years that the fishery resource is no longer under threat to the same degree as heretofore. This is not necessarily the case as this study demonstrates that fish kills are merely one indicator of many by which fish respond to deteriorating water quality. Effects of pollution on fish can be measured at different levels of biological organisation - at the cellular level, the organ level, the individual level, the population level or the community level. Effects can range i from fish kills, changes in fish density or species composition, or increasing incidence of water quality related diseases. This study reviews and examines the potential for an improved role for the use o f fish as biological indicators of the aquatic environment. In recent times, the most important advances have been made in computer software development and increasingly modules are becoming available which relate to resource and environmental management. The use of models is explored. AG.I.S based approach for the implementation of an integrated data collection, assessment, reporting and classification system suitable for use under Irish conditions is recommended. The ultimate aim should be to develop an improved fisheries environmental information system. The need is to identify and record existing data sets but also to incorporate newer technological advances into meaningful formats. These could then be correlated with water quality trends over time. The potential range of data sets are so varied that any new system should allow for the input of a large number of varied spatial and non spatial information, which should be linkable to related database information and be such that it can be integrated into a geographic information system. Fortunately, the G.I.S approach allows for this in so far as the basic environmental module can be expanded upon by the user depending on the nature of the databases under examination. It would also facilitate a uniform and integrated approach in which fish by virtue of their absence, presence, relative abundance, health status etc. would reflect prevailing environmental conditions in a manner that was not possible heretofore.