Seasalt Is More Than NaCl

All figures are available on the companion website in color (if applicable). 

Because water is a universal solvent, at least some of virtually every element is present as a solute in seawater. As shown in Table 3.1, the most abundant substances in seawater are the major ions (Cl , Na , SO4 , Mg , Ca , and K ). They are present in nearly constant proportions in the open ocean because their concentrations are largely controlled by physical processes associated with water movement, such as transport by currents, mixing via turbulence, evaporation, and rainfall. These solutes are also referred to as conservative ions. Most of the rest of the solutes in seawater are not present in constant proportions because their concentrations are altered by chemical reactions that occur faster than the physical processes responsible for water movement. These chemicals are said to be nonconservative. Though most substances in seawater are nonconservative, they collectively comprise only a small fraction of the total mass of solutes and solids in the ocean. 

The last two entries in Table 3.1 are not solutes. From a theoretical perspective, true solutes have diameters less than 0.001 pm (10A).True solids have a particle 

Solids Organic Particulate Matter Inorganic Particulate Matter ng/L to mg/L ng/L to mg/L Plankton biomass, fecal pellets, molts, feeding nets Atmospheric dust, riverborne clay minerals, iron oxyhydroxides, micrometeorites 

Colloids Organic Colloids Inorganic Colloids iron oxyhydroxides 

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