A devastating pollution incident has wiped out a significant number of fish, eels, and birds in the Knockando burn, a tributary of the River Spey in Moray. A chemical, thought to be caustic soda, is understood to have entered the water, "destroying" various species in recent days. The Scottish Environment Protection Agency (Sepa) is investigating the potential pollution. Fly fishers warn the burn's salmon population has been "wiped out" and could take years to recover. Duncan Ferguson, director of the Spey Fishery Board, said the pollution incident was one of the largest he had seen in 36 years of working on the river, with a two-kilometre stretch of the Knockando burn affected. He said: “It’s a tragic event. “It’s a really bad outcome and it didn’t have to happen.” He said the salmon population could face a five-year period of recovery, with a two-kilometre stretch of the burn “destroyed”.…