Cleaning Up Oahu’s Costal Waters, the Role of Tube-Building Polychaetes in Sediment Dynamics
3/1/10 – 2/28/11
Marine sediments in coastal waters and their biota are affected by human disturbance. Drainage from land, groundwater incursion and seasonal effects such as high surf are all part of the natural dynamics of coastal sediments. Recent efforts to remove introduced algae on Oahu’s shallow reefs are ongoing to restore the native biota in these coastal communities. This will result in improved water clarity, enhanced recreational use and greater species richness. Destabilization of sediments may occur as algal holdfasts are pulled from the substrate and sediment lodged among the branches could become suspended in the water and transported by water motion. Tube building and gregarious polychaetes that fix sediments in their tubes occur on these reefs and play a useful role in anchoring sediments. Some attach algal fragments to the tube apertures as a source of food. This study resulted in an understanding of the fauna associated with the algae and tube building polychaetes, the presence of native and introduced species in the benthos, grain size composition of the sediments and rate of accumulation of sediment in the proposed study areas. Changes in these communities were defined when compared to previous research on the invertebrates of these fringing reefs and beaches.