Isn't environmental degradation the deterioration of the environment through depletion of resources such as air, water and soil; the destruction of ecosystems and the extinction of wildlife? If that's the definition then brookies in western Canada have caused environmental degradation by causing the extinction of westslope cutthroat trout in more than several streams in their native range.
I would be in favor of any management plan that would drastically enhance the status of any and all native species. Liberal harvest of invasives, poisoning where viable, barriers, closure of sensitive drainages while proper species re-establish and total c+r of natives where not under threat. One only has to look to what the Americans are doing to reestablish their native species and know what should be coming to a Park/Province near you. About time, I'm sick of watching the natives disappear from their streams. All trout are NOT equal.