Millions of pearl mussels wiped out by sewage pollution, say scientists

Millions of freshwater pearl mussels have been killed by sewage pollution of the River Spey in northeast Scotland over the last 15 years, according to scientific reports released under freedom of information law.

Experts from the James Hutton Institute in Aberdeen have revealed that the number of mussels in the river has halved from 10 million in 1998-9 to five million in 2013. They blame high levels of phosphorus and other pollutants in sewage discharges for the decline, along with other factors.