How did World War 2 affect the environment in europe? Where there some major effects on fauna and flora?

by manooelito
Wibble201

If I can ask a follow-up, is it known how much effect the battle of the North Atlantic had on marine life? I can't imagine tens of thousands of depth charges or hundreds of thousands of gallons of oil didn't affect the ecosystem in a negative way, were any studies done at the time or after?