Survey of PAH in low density residential stormwater ponds in coastal South Carolina: False dark mussels (Mytilopsis leucophaeata) as potential biomonitors

Abstract The distribution of PAHs was studied in sediment and false dark mussels, Mytilopsis leucophaeata , of three brackish stormwater retention ponds on Kiawah Island, a gated residential community and golf resort. Impervious surface in pond watersheds ranged from 5 to 30%. Sediment concentrations were lower than those found in other studies of suburban residential areas, and there were no significant differences among ponds or seasons. Mean ∑PAH 16 values for sediments in Ponds 67, 100, and 37 were 184.7 ± 101.3 ng g −1 , 67.5 ± 26.0 ng g −1 , and 84.3 ± 75.5 ng g −1 , respectively. Mussel ∑PAH 16 concentrations from Pond 67 in August (mean 734.5 ± 148.1 ng g −1 ), and from Pond 37 in December (mean 1115.1 ± 87.7 ng g −1 ), were significantly higher than other ponds. Mean ∑PAH 16 values for mussels in Ponds 67, 100, and, 37 were 555.9 ± 219.7 ng g −1 , 312.5 ± 99.1 ng g −1 and 737.8 ± 419.8 ng g −1 , respectively. The mean biota-to-sediment ratio was 7.6 ± 8.1. Isomer ratios generally suggested pyrogenic sources. False dark mussels are a promising indicator species for PAH contamination because they are abundant, easy to sample, bioaccumulate PAH profiles representative of the time-integrated sediment profiles, and their PAH levels are less variable than either stormwater or sediment samples.