Water quality has traditionally been assessed on the basis of physical and chemical measurements but numerous alternative approaches based on the flora and fauna of surface waters have also been proposed. The main approaches used in biological and ecological monitoring are described and the scientific basis behind such methods is considered in order to identify the key criteria for their successful implementation in water quality monitoring programmes. The key biogeochemical processes in rivers and lakes, emphasising the critical information required to interpret water quality monitoring data, are also presented.

Learning Outcomes: On successful completion of this module, students should be able to:

• Identify the influences of human activities on biological communities in surface waters
• Propose, with reasons, suitable indicator organisms in rivers and lakes
• Distinguish between biological communities and individual species as approaches for water quality monitoring
• Identify the influences of human activities on composition and behaviour of particulate matter in rivers and lakes
• Select examples of use of particulate matter to monitor contamination in rivers and lakes