Indicators and Models

Indicators and models are two kinds of tools in the toolbox, but their objectives are quite different. Indicators measure the actual status of the environment before, during or after an event such as the start of the aquaculture growing cycle. However, the relationship between the event and the indicator requires scrutinisation which is one of the reasons why several indicators should be used to describe the impact of aquaculture on the marine environment.  Indicators cannot predict any future environmental conditions, as models do. In the context of an EIA, indicators serve as a reference status or as a signal for environmental change (qualitative or quantitative) and form the basis of a monitoring programme.

Models however, can predict future conditions without any further measurements since they have been validated and field tested before use. Models are increasingly more flexible and precise, mainly due to increasing computer power, but their quality depends on the models underlying processes and validation of results through a large range of environmental conditions.

Using both indicators and models greatly increases the ability of scientists, regulators, producers and environmental consultants to carefully assess the potential impact of new aquaculture operations, to characterize and evaluate any actual impact, and to define areas where the impact of marine aquaculture could minimized.

Indicators and Models
Final selection of indicators