Protecting Aquarium Sea Mammals and Fish from Pile Driving Noise and Vibration

Marine mammals and fish on exhibit at the Maritime Aquarium in Norwalk, Connecticut were the subject of an extensive study to predict, assess, measure and control pile driving noise and vibration levels produced by an upcoming major railroad bridge replacement project occurring proximal to the aquarium. There was great concern that the aquarium's harbor seals, sea turtles and various fish species could be adversely affected or even harmed by the pile driving. This paper will describe the development of relevant criteria limits, prediction of pile driver noise and vibration levels, and most importantly, the extensive measurements that were performed during a live pile driver test program conducted in late-2018. Air-borne noise, ground-borne vibration and hydro-acoustic levels were measured in real time as test pile driving was conducted at six locations using three different types of pile drivers. The results proved successful in protecting the aquarium's sensitive species of concern, and in doing so, reassured FRA/CTDOT regulators, project designers and aquarium management that the bridge replacement project could be conducted safely.