Nickel and water: reaction mechanisms, environmental impact and health effects

Seawater contains approximately 0.5-2 ppb of nickel, and rivers contain approximately 0.3 ppb. Phytoplankton contains 1-10 ppm nickel (dry mass), resulting in a 10³-10⁴ bioconcentration factor compared to seawater. Bentic algae can be found both in freshwater and salt water, and may contain between 0.2 and 84 ppm nickel. Lobsters contain 0.14-60 ppm nickel, molluscs 0.1-850 ppm, and fishes between 0.1 and 11 ppm (all values based on a dry mass). Nickel occurs in water as Ni²⁺ (aq) and sometimes as NiCO₃. It may be either dissolved, or complexed with inorganic ligands. Nickel may also be bound to particles.