The struggle to compute total ocean primary production accurately and to determine the relative 

 significance of component ecosystems continues as more sophisticated tools become available. 

 The subtle complexities of such integrations are being pursued through research on the 

 physiology and biochemistry of photosynthesis and metabolic activities of single cells, the 

 rigorous intercomparison and evaluation of the methodologies of primary production 

 measurement, and the expanding range of primary production processes including photo- and 

 chemosynthetic bacteria, nitrogen fixation and the role of submicron "picoplankton." The 

 concept of new versus recycled production is sharpening definitions of regional potential for 

 secondary productivity (e.g., fish production). 



The promise of a renewed capability for large-scale synoptic satellite color sensing is 

 stimulating reexamination of the relative roles of shelf and open ocean waters in marine 

 productivity. It is also, of necessity, stimulating efforts toward quantitative calibration of 

 ocean color In terms of primary production in preparation for the next decade. These core 

 studies are particularly important for global (both coastal and open) ocean flux and 

 recruitment subinitiatives, as well as global productivity. 



2. Microbial Loop Processes. As little as two decades ago, marine bacteria and other 

 heterotrophic microorganisms were thought to be rather rare and largely inactive. They are 

 now known to be responsible for up to 50% of the total water column biomass. They can 

 consume up to 50% of the total primary production in some situations and over 80% of water 

 column respiratory activity remains after filtration through a 1 -micrometer filter. 



Growing knowledge of the vital and active role of microorganisms in marine food chains has 

 vastly complicated the old "simple" diatom-copepod-fish short food chain concept. We now 

 realize that intricate microscale food chains may be responsible for rapid recycling of material 

 in the upper water column and transformation of detrital remains sinking to the ocean floor. 

 Further definition of the role of ocean microbes will provide a major component of ocean flux 

 studies. 



3. Higher Trophiic Levels. Ecological studies of populations and communities above the 

 microbial level and their behavior and ecological interactions have also added immeasurably to 

 our current understanding of the sophistication of ocean ecosystems. One significant example is 

 the exotic gelatinous zooplankton. Their importance was first determined by scientists using 

 near-surface scuba techniques; submersibles are now being used for studying them at greater 

 depths. In standard texts on marine invertebrates, whole chapters can now be written where 

 formerly groups such as Foraminifera, Radiolaria, salps, ctenophores, and chaetognaths were 

 dismissed in a sentence or two. 



Complex predator/prey interactions are being explored in imaginatively designed field studies 

 and in controlled laboratory studies. Sophisticated instrumentation is being developed to analyze 

 swimming behavior in three dimensions, to slow down millisecond-rate activities of the 

 microscopic mouth parts of copepods, and to measure flow velocities over feeding appendages of 

 benthic organisms. The biochemical basis of larval settlement and the competitive overgrowth 

 of clonal encrusting organisms are but two examples of ecological studies needing support for a 

 better understanding of major groups of organisms comprising coastal and oceanic ecosystems. 

 Basic life history and biology studies of individual populations are requisite for understanding 

 the seasonal, interannual, and longer scale regulation of populations and communities, and they 

 are relevant to the recruitment processes and ecosystem dynamics subinitiative. 



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