Figured I might as well mention, we do have a backhoe, I could probably talk him into digging some of it out if you really think it'll help.
It'd definately help. The nutrients build up over years and years, and just keep getting recycled. Removing them is the only way to help (long term). Tilapia remove the nutrients by getting themselves removed from the pond by scavengers and by us in the Fall, but a backhoe would really speed up the process. Dig out as much muck as possible, and put it where rain won't wash it or the nutrients back into the pond. I realize that it might be hard to do considering the slope of the property, but do the best job you can.
It'd help if you were to pump water out so you aren't digging in the water and stirring things up. Even if you can drain it dry and have a water trough for the cattle while the pond is dry, it'll be better than working in the slop.
