Can you over brush a dock?

Me and a buddy of mine put out 8 nice size cedars average size was 8' to 10' in 18' fow, we put them down the same finger (walkway) that runs between the two boat slips hanging 4 on one side and 4 on the other side from the dock support post so they probably touch each other underneath the dock. They've been wet now for about a year, before we put these out you could catch a few fish but never much of a mess, since they've been out I think we caught a total of 3 fish there, was expecting much better results.