I hate to muddy the waters but I am sure your crawdads beat me to it. They call them "mud bugs" for a reason. It's not a matter of too many fish, it's a matter of, too many crawdads.
Hopefully they are signal crawdads? As bad as signal crawdads are, any other species n your area would be worse and irresponsible.
Crawdads will voraciously feed on fish spawn. As a result, zoo plankton will increase and DO will decrease causing blue algae, like, gleotrichia to spike since it is a less desirable food source.
