Global Assessment of Silver Pollution using Sperm Whales (Physeter macrocephalus) as an Indicator Species

摘要

Silver pollution in the marine environment is of concern, particularly, with the rapid increasing use of silver nanoparticles in consumer products providing additional sources of silver emissions. Silver is highly toxic and known to bioaccumulate in aquatic organisms; however, the risk silver poses to the marine ecosystem is poorly understood. The sperm whale (Physeter macrocephalus), a toothed whale having a wide global distribution and high trophic level, is a sentinel of ocean health. The aim of this study was to provide a global baseline for silver as a marine pollutant using the sperm whale as an indicator species. Skin biopsies were collected in free-ranging sperm whales around the globe during the voyage of the research vessel, Odyssey, during 2000 and 2005. Total silver levels were measured in 298 sperm whales from 16 regions. Detectable levels were found in 176 whales and ranged from 0.1 to 4,179.0 μg/g ww with a global mean level of 16.9 ± 14.1 μg/g ww. The highest mean level was found in whales sampled in waters near Seychelles with 123.3 μg/g ww, and the lowest mean in whales near Chagos with 0.1 μg/g ww. These data provide an important global baseline for silver pollution that precedes the recent emergence of silver nanoparticles.