AUTOMATED INSTRUMENTATION FOR TIME-SERIES MEASUREMENT OF PRIMARY PRODUCTION AND NUTRIENT STATUS IN PRODUCTION PLATFORM-ACCESSIBLE ENVIRONMENTS

A major limitation to the assessment of the temporal and spatial varia bility of key ecological parameters is the ability to perform complex biological and chemical procedures autonomously in situ. We present ne w instrumentation for the automated in situ measurement of photosynthe sis and other microbial processes and for assessment of micro-nutrient pools in coastal and oceanic environments. High resolution time-serie s studies of photosynthesis using a submersible incubation device (SID ) indicates that the standard sampling interval commonly employed in c oastal and oceanic studies can lead to significant errors in the deter mination of the temporal patterns of photosynthesis and quantification of integrated measures of production expressed on a seasonal or annua l basis. Clearly, methodologies that allow for the higher frequency me asurements required to quantify this key ecological parameter adequate ly are needed. In addition, SID technology was found to avoid both pot ential handling artifacts of standard techniques. Since photosynthesis rates must often be interpreted in context with the nutrient regime o f the environment, an autonomous in situ continuous flow chemical anal yzer (in situ-CFA) has be developed for parallel deployment with the S ID. Both SID and in situ-CFA instruments, when incorporated into regio nal arrays of automated moorings that are supported by offshore platfo rm research programs, should greatly facilitate the gathering of data essential to our understanding of the meso-scale processes controlling biological systems in the coastal and oceanic environment.