Prochlorococcus, the most abundant photosynthetic organism on Earth and a crucial component of oceanic food webs, faces increasing threats from rising global temperatures. Yet, its sensitivity to temperature remains poorly understood, hindering our ability to predict its response under future climate change scenarios. This presentation will examine the thermal niche of Prochlorococcus using a decade-long record of in-situ measurements across vast regions of the surface ocean. We will present novel findings on the temperature dependence of Prochlorococcus division rates, revealing a critical thermal threshold with significant implications for its productivity and distribution. Furthermore, we will discuss the potential for shifts in phytoplankton community structure and trophic interactions as a consequence of future Prochlorococcus decline, based on projections from an ecosystem model incorporating our empirical findings. Our results underscore the vulnerability of Prochlorococcus-dependent marine food webs to future warming and highlight the urgent need to understand the ecological consequences of ongoing climate change.
Presentation Preference: Oral
Primary Presenter: François Ribalet, University of Washington (ribalet@uw.edu)
Authors:
Stephanie Dutkiewicz, Massachusetts Institute of Technology (stephdut@mit.edu)