Effects of environmental factors on release of mercury from Berry's Creek (New Jersey) sediments and its uptake by killifish Fundulus heteroclitus

Sediments from the highly mercury-contaminated Berry's Creek in the Hackensack Meadowlands of New Jersey were brought into the laboratory to investigate the effects of different environmental factors on their release of mercury and its uptake by Fundulus heteroclitus. Sediments were placed in 16 aquaria in which conditions of pH (6 vs 8), salinity (0·3% vs 1·2%), aeration (aerated or unaerated) and stirring (stirred or not stirred) were varied. Mercury analysis was performed on Fundulus heteroclitus from the aquaria. Condition factor of the fish was also monitored. Low oxygen was associated with higher levels of mercury in the fish and with poorer condition. Stirring the sediment did not decrease fish condition, and was associated with lower Hg uptake. The concentration of mercury in the sediments in individual tanks was not related to the uptake by the fish. Monitoring of mercury levels of fish collected from Berry's Creek throughout the year revealed a 5-fold increase during the summer months.