The distribution of plankton is governed more by nutrients than by temperature. Large tracts of ocean are blue and sterile. The reason is that these areas lack one or more crucial nutrients for the photosynthetic plankton, upon whom all the others depend. Broadly speaking, areas near land masses get nutrients by rivers and wind. The key nutrient lacking in the Pacific ocean is iron, essential in molecules such as "ferredoxins", iron-sulfur proteins which do electron transfer in a range of metabolic reactions.