Worryingly, their population numbers in the UK have declined 59% since 1970.
Why is the decline of aquatic invertebrates problematic for wild fish?
1. Foundation of life
Small but all-sustaining, invertebrates are food for our wild fish, birds and mammals. Without invertebrates, the food web would collapse.
2. Excellent storytellers
Aquatic invertebrates live in our rivers for most, if not all, of their lives – sometimes for years. Over this time, they are directly exposed to the conditions of the water.
Every invertebrate species is unique, thriving in a specific set of conditions. So, the composition of invertebrates found can be utilised to indicate the types of water quality stress impacting a river. Because of this, using invertebrates provides insight into river health over a much broader period of time than that of a single-point water chemistry sample.