Ishan Joshi 1
Mercury Contamination in Aquatic Ecosystem
Term Paper [Chemical Oceanography-4126] Ishan Joshi Department of Oceanography and Coastal Sciences
Mercury is the unique and toxic element that resides in small amount in the atmosphere, the hydrosphere and the biosphere. After industrial revolution and increased anthropogenic activities, concentration of elemental mercury and its compounds has increased about 3-4 times in the atmosphere which resulted life-threatening and devastating influence on marine and terrestrial ecosystem. Increment in atmospheric mercury concentration resulted elevated mercury loading in the upper ocean. More than a half of the human population depends on salt water and fresh water fish for their daily diet. Since fish is the main target of mercury contamination, humans are at a lifethreatening risk by toxic effects mercury. Thus, production of toxic methyl-mercury in the upper ocean due to bio-accumulation and build-up of this poisonous compound in marine food web due to bio-magnification is of a vital concern for the humans. Study of marine biochemical cycle of mercury with its potential sources and sinks is really necessary to find effective remedies to diminish the dangerous effects of this shiny-white metal. This review presents biological and physical processes that drive biochemical cycle of mercury in the global oceans with the potential sources (such as river, atmosphere, sediments, and hydrothermal vents) and sinks (such as bioaccumulation in marine fish, and scavenging due to sinking particles). Spatial, vertical and temporal variations of elemental mercury and human exposure to deadly effects of methyl-mercury are also presented in this study.
Ishan Joshi 2
Mercury occurs naturally in the Earth’s biochemical system. It is a highly volatile trace metal. Before an industrial revolution, the concentrations of mercury were fairly constant and harmless to our environment. In past few...