Chapter 14: Particulate Organic Detritus

Abstract
Our hydrosphere, of which the oceans constitute by far the greatest portion, is far from being a clear, homogeneous solution of dissolved salts. Rather, it is a highly complex, heterogeneous system of particulate materials, ranging in size from macroscopic aggregates down to colloidal micelles of solid, liquid, and gaseous nature, dispersed in an aqueous saline medium. Furthermore, the content of dissolved salts ranges from a few fractional parts per million in fresh alpine lakes and in granite-floored streams which feed them, through somewhat more substantial concentrations near the mouths of large rivers and in estuarine waters, achieving values of 33.0 to 35.0‰ in the sea, and up to full saturation (ca 300 ‰) in natural or man-made, landlocked bodies of salt water. Concentrations of leptopel (Fox, Isaacs, and Corcoran, 1952), the finely particulate organic and inorganic matter suspended in natural waters, are minimal in clear, blue mountain lakes, are probably highest in sluggish or stagnant waters of tropical or subtropical swamps, and occupy intermediate but widely varying values in the oceans. The various colors of marine waters, from deep blue in oceanic areas through various shades of blue green, yellow green, or even ruddy or brownish in neritic or near-shore regions, reflect the general turbidity and corresponding amounts of responsible microplankton and particulate organismal products of decay or excretion. Concentrations of organic (e.g., protein, lipid, and polysaccharide) and inorganic leptopel (silicates, insoluble carbonates, phosphates, hydrous oxides, etc.) and proportions between these two classes of suspended matter are highly variable, even...