Polycyclic Aromatic Hydrocarbons in Subcutaneous Blubber of the Florida Manatee (Trichechus manatus latirostris)

The Environmental Protection Agency has listed 16 polycyclic aromatic hydrocarbons (PAHs) as priority pollutants because of their carcinogenic and deleterious effects on aquatic organisms. PAHs may be found in the waters around electricity generating plants and in ports in Florida due to contaminated effluents. The characteristic high turbidity of Florida waters also causes the carcinogenic PAHs to become more bioavailable. Florida manatees (Trichechus manatus latirostris) frequent both power plants and ports and therefore are highly susceptible to PAH accumulation. Recently manatees have shown symptoms characteristic of PAH accumulation, e.g. impaired immune response, prolonged umbilical healing, and eye pathology. To date no studies have been published on PAH accumulation in manatees. The purpose of this study was to conduct an investigation of the levels of PAHs in the Florida manatee. Twenty-eight subcutaneous manatee blubber samples were obtained from the Florida Fish and Wildlife Conservation Commission Marine Mammal Pathobiology Laboratory archive. PAHs were extracted using an ASE 100 Accelerated Solvent Extraction System (Dionex Corporation, Sunnyvale, CA), and the 16 primary pollutant PAHs were quantified using high pressure liquid chromatography (Perkin- Elmer Corporation, Boston, MA) with a Vydac 201TP5415 reversephase (C18, 5 μm, 4.6 mm ID x 150 mm) HPLC column (Grace Vydac, Hesperia, CA), and calibrated by comparison to a standard priority pollutant PAH mixture. PAHs were found in the concentration range of 0.001-23.565 g/g. PAH concentrations showed a mean of 1.15 mg/g for total PAHs, and a mean of 1.25 mg/g of carcinogenic PAHs. These values compare respectively to literature mean values of 9.05 mg/g and 0.31 mg/g in a planktophagus whale and 36.21 mg/ g and 0.938 mg/g in a teuthophagus dolphin, both of which live offshore. These preliminary results indicate that Florida manatees are accumulating PAHs and that this accumulation may result in deleterious effects on their health, reproduction, and survival