Fishing all up and down the Arkansas River in bass tourneys about 10-15 years ago they where so bad you had to throw a crankbait with a long steel leader or just bumping them with 20lb test would break you off. Then we got a year that we had no flow during a very hot summer and the water warmed into the mid 90's and it killed them off. Those things are bad news!! They have completely changed the fishing on the Great Lakes.