Impact of river marinas being dredged

Does anyone know what the usual impact of a marina getting dredged out is?  Saw some off the Ohio River where I fish getting dredged out.  Basically the guy was getting the silt from the middle of the marina and then dumping it outside the mouth into the creek.  I don't know what a typical size marina is but this one holds maybe 50 boats...not really sure.  It is no bigger or smaller than most of the other marinas I've seen up and down the river.

Just curious...mainly about short term impact...if the bass would relocate do to the disturbance or just sort of ignore it since he is digging mostly in the middle of the marina as far as I can tell.   Also wondering if they might be attracted to the possible hump he is creating by dumping the mud into one area of the creek.  This is bound to create an abnormality in the bottom structure I would think.  I dunno...maybe the current would smooth it out..

Any experiences with this would be appreciated.