Emission factor and balance of mercury in fish farms in an artificial reservoir in NE Brazil

摘要: This paper estimated the mercury (Hg), emission factor, and mass balance from caged fish farming in Castanhao Reservoir, NE Brazil, based on monitoring of a typical farm Nile tilapia (Oreochromis niloticus). The total Hg input to reached 1.45 gHg ha−1 year−1, which 0.21 gHg ha−1 year−1 was exported out as biomass, ultimately resulting an factor 1.24 for reservoir or approximately 8.27 mgHg ton fish−1 year−1 produced. Most came aquafeeds with concentrations varying 1.4 31.1 ng g−1, depending type aquafeed. were very low varied 1.0 2.9 ng g−1. These values are two orders magnitude lower than legal limit human consumption. annual discharge into is 174 g 18,000 tons produced may reach 387 g when reaches its capacity (40,000 tons), expected occur 2020. balance, considering deposition accumulation rates, showed that 40 % accumulate sediments (0.72 g ha−1 year−1), 60 % rate through sediment traps suggests 0.54 gHg ha−1 year−1 could eventually be transported reservoir. Notwithstanding these facts, Reservoir less 1.0 % anthropogenic sources.