Otters in the Lake!

I stand at the kitchen window and watch the waves in the lake made by our resident River Otters. I thought they were only passing through, but now they've been here long enough to be called resident... until they eat all the slow moving fish, that is.
I rarely see them, but I see huge rings of water and swirls rising from their antics underwater, mostly in the mornings. When I've walked around the lake they get curious enough to float with their heads and bodies just out of the water, like sea otters in California, and watch me. If I stop and look at them they'll dive, like porpoise.
I figure they're the ones who've been eating the Israeli Carp and leaving the skulls and sometimes the skeletons. They're called 'Fishermen's Friend', but all my redneck buddies tell me that I should let them kill them. A good pelt can sell for $1500!
Not in my lake! Too interesting to watch. Our lake needs some fish culling. Supposedly Bass are too fast for the Otters. We'll see!