Photosynthesis by phytoplankton, algal and marine plant forests as well as corals all sustain trophic webs that support marine biodiversity and food security worldwide. Marine primary productivity (MPP) by these organisms ultimately sets the carrying capacity of coastal and ocean ecosystems, and profoundlyinfluences nutrient and mineral(re)cycling. MPP, however, exhibits complex environmental responses that are still poorly understood, and under global climate change MPP is rapidly turning from an indicator of ocean health to one of ocean decline, e.g. harmful algal blooms. Unlocking how MPP varies over space and time is critically needed to support management decisions that can safeguard marine ecosystem functioning, but until recently has remained a central challenge to marine science. New technologies now enable semi (or fully) automated chemical sensors to measure mixed layer dissolved gases (e.g. O2, N2, Ar, and CO2) as tracers of net community productivity, and bio-optical sensors of both photosynthetic community composition(and cell size) and ‘currencies’ of gross photosynthesis and export including electron transfer, ATP, and sinking rates. This session will consider how development and deployment of such technologies are rapidly transforming our understanding of MPP, and underpin a new era for synoptic assessment of ocean functioning. Furthermore, how more autonomous data collection modes via platforms, from mooring and ships of opportunities to satellites, can support regional water framework and marine strategy directives needed to deliver UN Sustainable Development Goals.