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 variability of key ecological parameters is the ability to perform complex biological and chemical procedures autonomously in situ. We present new instrumentation for the automated in situ measurement of photosynthesis and other microbial processes and for assessment of micro-nutrient pools in coastal and oceanic environments. High resolution time-series studies of photosynthesis using a submersible incubation device (SID) indicates that the standard sampling interval commonly employed in coastal and oceanic studies can lead to significant errors in the determination of the temporal patterns of photosynthesis and quantification of integrated measures of production expressed on a seasonal or annual basis. Clearly, methodologies that allow for the higher frequency measurements required to quantify this key ecological parameter adequately are needed. In addition, SID technology was found to avoid both potential handling artifacts of standard techniques. Since photosynthesis rates must often be interpreted in context with the nutrient regime of the environment, an autonomous in situ continuous flow chemical analyzer (in situ-CFA) has be developed for parallel deployment with the SID. Both SID and in situ-CFA instruments, when incorporated into regional arrays of automated moorings that are supported by offshore platform 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.