Low Mercury Levels in Lake Kinneret Fish

Abstract Human exposure to the neurotoxin, methylmercury (MeHg), occurs primarily through the consumption of contaminated fish that are present even in pristine freshwater ecosystems. Lake Kinneret is the sole freshwater lake in Israel and supports an important commercial fishery. We examined total mercury (THg; often equivalent to MeHg in fish muscle tissue) for nine fish species in Lake Kinneret. Concentrations were low for all fish species, 6-409 ng/g, and below 500 ng/g MeHg, the level generally considered safe for human consumption. Of particular relevance are the very low levels of THg (<60 ng/g) in Galilee St. Peter's fish (Sarotherodon galilaeus) and lavnun (Acanthobrama terrascantae), the most commercially important species in Lake Kinneret. Biomagnification was apparent among trophic guilds, with THg concentrations increasing from primary to secondary to tertiary consumers. This study suggests that consumption of commercial species, especially primary consumers, will result in low MeHg exposure to humans