NCCOS scientists recently used tidal estuarine simulation units (mesocosms) to study the crude oil-removal efficiency of shoreline cleaners and the potential impacts of removed oil on an estuary. Oil spills that occur in estuaries, bays, or enclosed harbors have the potential to contaminate docks, bulkheads, ship hulls, and sensitive estuarine habitat. Depending on the situation and location, shoreline cleaners may be applied to oiled surfaces within inshore areas.
In the mesocosms, crude oil was applied during three consecutive high tide events. After the oiling, hard surfaces in some of the mesocosms were cleaned using three different shoreline cleaning products designed to lift and float oil back onto the surface of the water. The exposure lasted for 30 days from the initiation of the simulated spill. Scientists are now examining the data collected during the spill to evaluate: (1) how well the various products removed oil from hard surfaces in the mesocosms; and (2) the effects of the removed oil mixed with the cleaners on marsh vegetation, sediment organisms (amphipods, polychaetes, and clams), fish, shrimp, and bacterial communities.
Ceramic tiles were used as the hard surfaces to test oiling and removal efficiency. Water and sediment samples collected during the study are being analyzed to determine how the oil concentration and composition changes over time. The results of this study will help managers weigh thepotential risks and advantages of using shoreline cleaners in the coastal zone.