Using aeration to probe the flow characteristics associated with long-term marine macrofouling growth and suppression

Abstract

It is well-established that hydrodynamics affect the settlement of biofouling organisms. Laboratory studies have demonstrated a connection between larval attachment rates and the prevalence of time windows that satisfy certain instantaneous flow conditions. However, it is unclear whether a link exists between short-term hydrodynamics and long-term macrofouling survival and growth, or if it is applicable at an ecosystem-wide level. This study used single bubble stream aeration in field and laboratory experiments to find critical flow characteristics that correlate to long-term, multi-species fouling prevention. The research was accomplished by combining PIV-derived flow statistics with fouling severity measured over seven weeks in the field. Flows with a decreasing proportion of time windows defined by a flow speed < 15.1 mm s−1 for longer than 0.03 s correlated to decreased biofouling growth and survival. These results provide a potential framework for studying and comparing flow fields that successfully inhibit biofouling growth.