Accumulation of Silver in Yellow Perch (Perca flavescens) and Northern Pike (Esox lucius) From a Lake Dosed with Nanosilver

A total of 15 kg of silver nanoparticles (AgNPs) was added continuously over two ice-free field seasons to a boreal lake (i.e. Lake 222) at the IISD-Experimental Lakes Area in Canada. We monitored the accumulation of silver (Ag) in the tissues of yellow perch (Perca flavescens) and northern pike (Esox lucius) exposed to the AgNPs under environmentally relevant conditions. The greatest accumulation was observed in the liver tissues of pike, and a single pike sampled in the second year of additions had the highest concentration observed in liver of 5.1 µg/g wet weight. However, the Ag concentrations in gill and muscle tissue of both pike and perch did not exceed 0.35 µg/g wet weight. Following additions of AgNP, the Ag residues in fish tissues declined, with a half-life of Ag in pike liver of 119 days. Monitoring using passive sampling devices and single particle ICP-MS during the AgNP addition phase confirmed that Ag nanoparticles were present in the water column and estimated mean concentrations of Ag inc...