Effects of Beach Renourishment on Inshore Macroinfauna off John U. Lloyd Beach State Park, Broward County, FL

Effects of Beach Renourishment on Inshore Macroinfauna off John U. Lloyd Beach State Park, Broward County, FL

The marine benthic macrofauna at John U. Lloyd Beach State Park (Broward Co., FL) has been surveyed at intervals since 1987 to examine effects of periodic beach renourishments. The current study followed the most recent renourishment, which ran from May 2005 to February 2006. A total of 20 quantitative sediment core samples (926.667 cm3) were taken from four sites (5 replicates per site), ~100 m offshore at depths of 2-5 m in May 2007. Samples were fixed in 10% seawater formalin with Rose Bengal stain, and subsequently passed through a 0.5-mm-mesh sieve and transferred to 70% ethanol in advance of sorting and identification under light microscopy. The dominant organisms were polychaetes (chiefly Paraonis fulgens), amphipods (e.g.,Metharpinia floridana, haustoriids) and the bivalve Tivela floridana. Organism densities were lower than those recorded during previous renourishment surveys of the same area, but species richness appeared greater than in most previous samples. The current study was carried out a little over a year following the renourishment. Previous work also recorded decreases in organism abundances following renourishment. Further monitoring will be needed to assure that such effects are resolved with time for acceptable organism recovery.