ABSTRACTS

Oral Session 1 | Monday, October 3, 11:40–12:00 | Abstract 638

Single Turnover Active Fluorometry (STAF) allows for in-situ assessment of phytoplankton optical properties and primary productivity

Single-Turnover Active Fluorometry (STAF) instruments can provide real-time, high-resolution data on in-situ phytoplankton physiology and photosynthetic rates. Over the past years, considerable progress has been made in the development and application of STAF in aquatic ecosystems, and interpretation of the resulting observations. Unprecedented data resolution has now routinely been achieved with fully autonomous LabSTAF instruments (CTL, West Molesey, UK) connected to continuous seawater supplies on research ships and buoy-based installations. Most recently, autonomous measurements have also successfully been made with a deployable AutoSTAF system (CTL, West Molesey, UK) installed on an AUV (AutoSub LR, National Oceanographic Centre, Southampton, UK). We present new data of direct comparisons between STAF-derived photosynthetic rates (µmol electrons m^–3 s^–1 ) and 14 C-uptake based primary productivity (µmol C m^–3 s^–1 ) which further our understanding of the utility of STAF to assess primary productivity by phytoplankton at unprecedented spatial and temporal resolution. In addition, we present data highlighting STAF capabilities for the assessment of phytoplankton optical properties of interest to the ocean optics community. We explain how the use of multiple excitation wavelengths allows for the routine assessment of spectral light absorption and utilization capabilities of phytoplankton communities and the implementation of fluorescence emission detection at two wavelengths provides a proxy for the pigment packaging effect.

Nina Schuback, Chelsea Technologies, 0000-0001-9535-0086

C. Mark Moore, University of Southampton at NOCS

Mary N. Burkitt-Gray, Chelsea Technologies

Alan Wright, University of Southampton at NOCS

Kevin Oxborough, Chelsea Technologies