Chapter 6 - Fishes and Estuarine Environmental Health

This chapter addresses the use of fish as indicators of environmental health. The main anthropogenic pressures impacting estuarine fishes are reviewed, as well as the main types of responses by fishes at different levels of biological organisation. Fishes have been widely used to assess estuarine health through different methodological approaches, namely comparisons with historical data or reference conditions, experimental approaches, environmental impact or risk assessment methods, as well as qualitative or quantitative indicators and models. A large number of multi-metric indices based on fish have been proposed and are routinely used in environmental assessments, although to disentangle natural variability from anthropogenic pressures in a multi-stress context of global change is still a major challenge.