Effects of contamination from Antarctic research stations on marine benthic fauna

Antarctica is our most pristine continent, home to many unique and scientifically interesting ecosystems. But the presence of researchers and supporting infrastructure are unintentionally causing localized pollution at research stations, which is adding to the stress of climate change in Antarctica. Therefore, it is important to determine the extent of this contamination so that careful environmental management can be ensured. This dissertation identified long-term decreases in mercury, copper, organochlorine, and polycyclic aromatic hydrocarbon (PAH) contamination at McMurdo Station, the largest, and possibly most polluted, research station in Antarctica. However, these long-term (13 year) decreases in contaminants were not great enough to allow the recovery of affected macrobenthic communities. Instead, changes in macrobenthic communities at both polluted and references areas coincided with climate cycles and changes in sea ice characteristics, indicating effects of global climate change. Bioaccumulation of trace metals, pesticides, and/or organochlorines from McMurdo Station occurred in ten of twelve epibenthic species sampled, although polychlorinated biphenyls (PCBs) in benthic fish (Trematomus spp.) were of most concern. Bioaccumulation of PAHs, copper, lead, and zinc in a limpet (Nacella concinna) occurred at Palmer Station, a medium sized Antarctic research station, although concentrations have decreased since the 1990s. The effects of local contamination on macrobenthic fauna communities adjacent to Palmer Station could not be differentiated from the effects of natural variables, which indicates that smaller stations may have a smaller influence (intensity and/or spatial extent) on the local environment. Legacy contamination in the marine environment persists adjacent to Antarctic research stations. However, continued careful environmental management and varying amounts of time (years to decades) may allow contamination to further decrease and ecosystems to recover.