SUBMERSIBLE INCUBATION DEVICE (SID), AUTONOMOUS INSTRUMENTATION FOR THE INSITU MEASUREMENT OF PRIMARY PRODUCTION AND OTHER MICROBIAL RATE-PROCESSES

A Submersible Incubation Device (SID) is described that will conduct three sequential time-course incubation experiments directly in situ. Each incubation involves a cleaning cycle, procurement of a 400 ml sample at depth, with simultaneous introduction of fresh tracer, and the time-course preservation of four subsamples for analysis upon retrieval of the instrument (12 subsamples total). The instrument records elapsed time, pressure (depth), light intensity, temperature and battery voltage throughout the deployment. The instrument has been used successfully for measurements of phytoplankton production in the open ocean and coastal wates. Three modes of operation have been employed: (a) a mode for obtaining daily rate information by summation of data from multiple short-term incubations, (b) a rapid profiling mode for measurement of microbial rate processes at several depths during a single deployment, and (c) an unattended time series mode for obtaining representative short-term activity measurements at several day intervals. The described instrument is a prototype for a long-term (months) time series version deployable in the open ocean or in remote locations. © 1990.