Report Number: 151
Year: 2015

Utility of the Soft Coral, Sinularia polydactyla as a Biomonitor of Polychlorinated Biphenyls (PCBs) in Tropical Marine Waters: A Preliminary Assessment

The objective of this research was to evaluate the soft coral Sinularia polydactyla as a biomonitor for polychlorinated biphenyls (PCBs). Potential influences on PCB accumulation were examined in sets of wild colonies. Uptake and depuration kinetics were measured by transplanting colonies and sampling over a 90 day period. All samples were lyophilized, extracted by accelerated solvent extraction, and analyzed by gas chromatography.

Spawning was discovered to impact PCB concentrations. Due to rapid physiological changes, within-colony differences were significant. Increases in lipid content in reproductively active portions of the colonies were not matched by increases in PCBs. During spawning, the new lipids were off-loaded while PCBs were not.

Post-spawn, within-colony differences abated. Gender and water column position were not significant factors. Most importantly, there was little variation among colonies. Analysis by lipid weight eliminated differences between age/size groups. Overall, the comparison studies revealed that S. polydactyla is well suited for biomonitoring outside of the spawning season.

The kinetics data provided strong evidence that Sinularian corals reflect ambient PCB levels. Uptake and depuration generally followed first-order kinetics. There was a degree of PCB metabolism and bioaccumulation in S. polydactyla. However, it was on par with what has been recorded in other aquatic species. Overall, it appears that S. polydactyla can be useful for PCB monitoring and Aroclor characterization. The use of S. polydactyla for at least basic PCB surveys or as part of a suite of monitoring organisms is warranted.

Paulina M. Welch
Peter J. Schupp
Gary R.W. Denton