The River Shannon is Ireland’s longest river (224 miles, 360 km) and discharges on average more than 200,000 litres of water per second into the Shannon estuary at Limerick, where it enters the sea. That is the same volume as 5 Olympic-sized swimming pools every minute!
Half of all the endangered freshwater pearl mussels in Europe live in Irish rivers. Riverbanks provide wildlife corridors through the countryside and give food and shelter for a wide range of animals and plants. They also serve as an important habitat for many wildflowers that support butterflies and bees.
Biological monitoring has been carried out in Irish rivers since 1971. The current national river monitoring programme covers more than 13,000 km of river channel.
Source – Grasshopper Geography