Bottom trawling for fish is so destructive to marine environment that its plume can be seen from space!
"Bottom trawling is the most destructive of any actions that humans conduct in the ocean," said zoologist Les Watling of the University of Hawaii. "Ten years ago, Elliott Norse (of the Marine Conservation Biology Institute) and I calculated that, each year, worldwide, bottom trawlers drag an area equivalent to twice the lower 48 states. Most of that trawling happens in deep waters, out of sight. But now we can more clearly envision what trawling impacts down there by looking at the sediment plumes that are shallow enough for us to see from satellites."