Collecting data in the River Lea, London (IMAGE) University College London Caption Collecting data in the River Lea, Hackney Downs, London, surveying for freshwater invertebrates using the ‘Riverfly’ citizen science method, which is used across the UK by volunteers. Invertebrates are sensitive to changes in water quality, so they are a good indicator of pollution. Credit: Dr Izzy Bishop Credit Dr Izzy Bishop, UCL Usage Restrictions With credit and linked to this research story License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.