Biomagnification of Perfluoroalkyl Compounds in the Bottlenose Dolphin (Tursiops truncatus) Food Web

Abstract

The environmental distribution and the biomagnification of a suite of perfluoroalkyl compounds (PFCs), including perfluorooctane sulfonate (PFOS) and C8 to C14 perfluorinated carboxylates (PFCAs), was investigated in the food web of the bottlenose dolphin (Tursiops truncatus). Surficial seawater and sediment samples, as well as zooplankton, fish, and bottlenose dolphin tissue samples, were collected at two U.S. locations: Sarasota Bay, FL and Charleston Harbor, SC. Wastewater treatment plant (WWTP) effluents were also collected from the Charleston area (n = 4). A solid-phase extraction was used for seawater and effluent samples and an ion-pairing method was used for sediment and biotic samples. PFCs were detected in seawater (range <1-12 ng/L), sediment (range <0.01-0.4 ng/g wet weight (ww)), and zooplankton (range 0.06-0.3 ng/g ww). The highest PFC concentrations were detected in WWTP effluents, whole fish, and dolphin plasma and tissue samples in which PFOS, C8 and C10-PFCAs predominated in most matrices. Contamination profiles varied with location suggesting different sources of PFC emissions. Biomagnification factors (BMFs) ranged from <1 to 156 at Sarasota Bay and <1 to 30 at Charleston. Trophic magnification factors (TMFs) for PFOS and C8-C11 PFCAs indicated biomagnification in this marine food web. The results indicate that using plasma and liver PFC concentrations as surrogate to whole body burden in a top marine predator overestimates the BMFs and TMFs.