But man isn't the only animal making trails in the woods. Actually it's a sign of a healthy woods if there's lots of trails. Deer have well traveled paths. It becomes very apparent if you walk into the woods (which I'm sure you have) right after a snow fall. there are little trails used by more than one animal all over the place. Same with reefs. Man may bang them up a bit but look at parrot fish, especially Hump Heads. And hawks bill turtles? They're like rats in a grain bin. I've seen them draped over large spounges munching away on them at Sipadan. Are they environmentalists? Are the deer?
Of course animals make trails. Animals will also use man-made trails like bike paths WHEN there aren't bikes running up and down them.
I think our impact as divers is minimal. It's the big things like industrial runnoff, temperature change etc etc that are rough on the reefs.
I think you need to qualify that. I agree that there are bigger threats to the environment worldwide. However we have run-off, polution and climate change everwhere. There are relatively few divers diving in relatively few places. The problem is that in some of those few places that see lots of divers, the damage is pretty extensive.
Not only that, but the damage the divers do is completely avoidable.