Mercury offloaded in Northern elephant seal hair affects coastal seawater surrounding rookery

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Cossaboon, Jennifer M., Ganguli, Priya M., Flegal, A. Russell
• Format: Text
• Language: English
• Published: National Academy of Sciences 2015
• Subjects: Physical Sciences; Elephant Seal
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4593100/; http://www.ncbi.nlm.nih.gov/pubmed/26372960; https://doi.org/10.1073/pnas.1506520112

Mercury is a potent neurotoxin that accumulates in food webs, posing a global threat to environmental health. Marine mammals are common sentinel species for studying marine pollution; however, their potential role as vectors of contaminants to local ecosystems has rarely been addressed. By quantifying the concentration and chemical form of mercury in seawater affected by Northern elephant seal (Mirounga angustirostris) colonization, we demonstrated here that marine mammal behavioral ecology can substantially influence nearshore mercury cycling. Elevated methylmercury (MeHg) levels in seawater adjacent to the rookery during the molting season may become bioavailable to lower trophic levels, indicating that large marine mammal assemblages represent an important source of MeHg to nearshore food chains and coastal marine fisheries, thereby threatening ecosystem health.