Natural colour satellite image showing phytoplankton blooms in the Barents Sea, situated off northern Scandinavia and north-western Russia. Phytoplankton are microscopic marine plants that live in both freshwater and saltwater. Phytoplankton blooms occur when deep currents bring nutrients up to sunlit surface waters, fuelling the growth and reproduction of the phytoplankton. in the Barents Sea, phytoplankton blooms peak every August. The bright blue colours in the satellite image are caused by the presence of coccolithophores, a group of phytoplankton that produce a calcerous shell around themselves. The green colours are from diatoms, another type of phytoplankton. Imaged by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA?檚 Aqua satellite on the 31st of August 2010.