OCCURRENCE AND RESPIRATION OF ULTRAPLANKTON IN UPPER 500 METERS OF OCEAN

By gentle concentration the ultraplankton of the open ocean were prepared for estimation of their rate of respiration and for microscopic examination while still alive. Except in coastal waters the predominant organisms of the upper 500 m in the western North Atlantic and Southeast Pacific were generally μ flagellates (2-10 μ). Most bacteria and many flagellates were associated with flocculent organic aggregates. Below 25-50 m most of the flagellates were non-pigmented. Evidence is presented that much of the energy fixed by photosynthesis is utilized by Protista. Organic aggregates appear to be the locus of much of the metabolic activity in the ocean. © 1968.