Toxicological Risks and Considerations Associated With Lipophilic Contaminant Burdens of Southern Ocean Mysticetes

• Main Author: Bengtson Nash, Susan
• Format: Book Part
• Language: unknown
• Published: Academic Press 2018
• Subjects: Environmental Sciences; Antarctic; Southern Ocean; The Antarctic; Antarc*; baleen whales; Sea ice
• Online Access: http://hdl.handle.net/10072/384168; https://doi.org/10.1016/B978-0-12-812144-3.00014-0

Southern Ocean foraging baleen whales, as with other capital breeders, represent a “special case” scenario for the evaluation of the toxicologic risk posed through lipophilic chemical exposure. Feeding on seasonally productive prey species, followed by extended fasting associated with energy intensive activities, such as migration, competitive breeding behavior, pregnancy, and lactation, results in massive fluctuations in lipid reserves. These fluctuations are mirrored in the toxicokinetics of lipophilic contaminant burdens, with significant mobilization and redistribution of contaminants taking place between the individual's tissues during this time. While the toxicologic consequence of this life-history behavior remains unquantified, fasting should be thought of as a time of “reexposure” of target sites of toxicity to harmful chemicals. Of significant relevance is the temporal cooccurrence of pregnancy and nursing of young calves, with elevated circulating maternal chemical burdens. Elevated maternal offloading of persistent organic pollutants to the young is further exacerbated by the disproportionate exposure experienced by the embryo and calf on account of a smaller body size. The interplay of multiple stressors, for example, chemical exposure, negative energy balance, and immune function, during migration remains a critical nexus of priority for future investigation. The importance of such investigations are underscored by the vulnerability of the Antarctic sea-ice ecosystem to the direct effects of polar climate change, which may result in further energetic challenges to Southern Ocean mysticetes, already adapted to metabolic extremes. No Full Text