The "muddy taste" is caused primarily by a specific specie of algae (Oscillatoria perornata) that produces 2-methylisoborneol (MIB), which imparts the nasty flavor to fish. The off-flavor has no direct correlation to water turbidity caused by suspended colloids (clays).
True. In fact, fish caught from turbid water is less likely to have an algae taste than fish caught from clear water. Of course that's because the turbid water inhibits algae growth.
