You guys go on about the deepest river, but the deepest Lake is Baikal, in Siberia, and it is the deepest of anything, so they say. It has fresh water sea lions and dolphins and seals swimming in it, and it has geothermal activity that stirs it, making it an oxygenated deepest lake.
It is having some environmental problems, tho. Some hotshot idiots are polluting it- there are no standards in place; they haven't even circumnavigated it with a walking trail- I mean I don't think anyone has been all the way around it yet-- they have volunteer trailblazing camps. I'd love to go, when my baby gets bigger