That pretty rich water. Are those strings stretched across the pond to deter birds? Are you feeding the crayfish and minnows? Did you once grow other fish there with feed ... eg catfish? It's nutrient rich for sure. Fish and crayfish aren't going to make it nutrient rich (though their standing weight might be relatively high due to the richness of the water). Only you would know how the nutrients were loaded ... so .... from where did the nutrients come from?
