where does mercury in the ocean come from
Mercury pollution in the ocean Mercury enters the ocean in different ways. Atmospheric deposition is the largest source of mercury to the oceans. Atmospheric deposition introduces three types of mercury to the ocean. Gaseous elemental mercury (Hg0) enters the ocean through air-water exchange. Inorganic mercury (Hg2+/HgII) and particle-bound mercury (Hg(P)) enters through wet and dry deposition. In addition, mercury enters the ocean via rivers, estuaries, sediments, and, hydrothermal vents etc.[11] These sources also release organic mercury compounds such as Methyl mercury. Once they are in the ocean they can undergo many reactions primarily grouped as; redox reactions (gain or loss of electrons), adsorption processes (binding to solid particles), methylation and demethylation (addition or removal of a methyl group).[1]
Oceanic carbon cycle Three main processes (or pumps) that make up the marine carbon cycle bring atmospheric carbon dioxide (CO2) into the ocean interior and distribute it through the oceans. These three pumps are: (1) the solubility pump, (2) the carbonate pump, and (3) the biological pump. The total active pool of carbon at the Earth's surface for durations of less than 10,000 years is roughly 40,000 gigatons C (Gt C, a gigaton is one billion tons, or the weight of approximately 6 million blue whales), and about 95% (~38,000 Gt C) is stored in the ocean, mostly as dissolved inorganic carbon.[2][3] The speciation of dissolved inorganic carbon in the marine carbon cycle is a primary controller of acid-base chemistry in the oceans.