i don,t know if their behavior is inapropriate . i,m in Northeastern PA , but when my water temp dropped below 50 degrees , my guys went to the bottom and don,t move much unless disturbed , check your water temps about 18 inches below the water surface

If the water temp is very cold, that is normal behaviour. But I suspect you may have something else going on. Your weather is a bit mild to drive them to the bottom. You need to get a test kit and check your water. Ammonia problems will cause fish to sit on the bottom. Are their pec fins out like normal or are they clamped to their sides? Clamping fins is a sure sign of trouble.