Insects of the river
While it is the fish that this project is all about. The reality is it's actually about all the things that make it a good river for fish. So really, it's a project that is all about water quality and conditions. In which case the best indicators of the health of a river are the insects that live beneath its surface. Insects and other invertebrates such as a multitude of crustaceans, worms and molluscs are small and highly specialised, adapted to very specific conditions. It is often their presence or absence of certain species that reveal information about the underlying quality of the water and the health of the aquatic ecosystem. In short, if things are good for insects and the river is supporting a rich and varied number of different kinds then it's going to be supporting a healthy population of fish, birds and mammals. While it's impossible to feature every insect that might creep, crawl, fly or hop into you as you explore the River Teign, there are a few that are either very distinctive, obvious or interesting.