Vertical Mixing, A Constraint to Primary Production: An Extension of the Concept Of an Optimal Mixing Zone

Abstract

Abstract The neating by the sun's energy provides buoyancy to surface layers of trie oceans which limits vertical mixing of the entire water column. A water column stratified by the buoyancy of the surface layers is low in important nutrients; thus, primary production and the stocks of phytoplankton are small. The buoyancy of surface layers and resulting stratification of the water column is a constraint to primary production and in turn to the ecosystem as a whole. Renewewed vertical mixing of the water column emphasizes the importance.of an optimal depth of mixing: this is the zone of the mixed layer where stresses due to light limitation are balanced by the addition of nutrients to surface layers.