Mercury and methylmercury uptake and trophic transfer from marine diatoms to copepods and field collected zooplankton

Mercury (Hg) and methylmercury (CH3Hg) are found at trace levels in most marine waters. These species, particularly CH3Hg, then ominously bioaccumulate through food chains eventually reaching potentially harmful top oceanic wildlife. Accordingly, it is important to measure evaluate uptake environmentally relevant concentrations where trophic transfer initiates; during primary producers, consumption by plankton grazers. Experiments using cultured copepods (Acartia tonsa) field zooplankton assemblages were performed with two different sized diatom species labeled stable isotopes of inorganic Hg (200Hg) CH3Hg (CH3199Hg) concentrations. We observed size-specific effects on algal copepods, addition concentration. Prey size likewise copepod assimilation efficiencies (AE). Average AE 200Hg for feeding smaller diatoms was 50%, 39% larger diatoms. The AEs much greater CH3199Hg, yielding 71% the 88% experiments add evidence demonstrating a significant relationship between exposure concentration subsequent zooplankton. Furthermore, results imply that facilitated into algae occurs low (~pM) concentrations, which has been suggested but not confirmed previous research.