Benthic Community Responses to the Filling of a Hurricane-Induced Barrier Island Inlet

摘要

In September 2003, Hurricane Isabel created a new tidal inlet through Hatteras Island, a barrier island of North Carolina (U.S.A.). Within two months, the breach was filled with sand dredged from nearby areas. Subsequent ecological response of the benthic macroinvertebrate communities to the filling differed on shores on opposite sides of the island. Thus, the filled area on the high-energy sandy beach exhibited convergence in community composition and abundance with a nearby reference area within 30 months, whereas the filled area on the lower-energy sound shoreline still possessed a depauperate benthos. The high volume of long-shore sediment transport documented along the ocean beaches of Hatteras Island probably acted quickly to transport benthic macrofauna to the fill along with natural beach sediments, and thereby activating a rapid ecological response of the beach community. The beach community was dominated by annual macroinvertebrate species, which could account for mixing from nearby areas in the rapid macrofauna community response. In contrast, the Pamlico Sound shoreline experiences only local wind-driven waves and modest long-shore currents likely insufficient to import macrobenthos readily. Infrequent passive transport of macrobenthos and persistence of defaunated sediment habitats nearby probably slowed the macrofauna community response on the sound-shore side. Management intervention through habitat restoration would be recommended in the less dynamic sound shore environment compared to the high-energy ocean beach where ecological responses of the invertebrate community occurred rapidly.