THE INFLUENCE OF PHYSICAL PROCESSES ON PHYTOPLANKTON COMMUNITY STRUCTURE IN THE GALAPAGOS ARCHIPELAGO

Phytoplankton are responsible for half of the total oxygen production, and are a key contributor to sequestering carbon dioxide from the atmosphere.  Different groups of phytoplankton (diatoms, dinoflagellates, green algae, cyanobacteria) compete for the same growth-limiting resources - light and nutrients - but each group of primary producers employs a set of unique strategies, which allows diverse communities to co-exist in time and space.  Physical processes and local topography of the Galápagos Archipelago play an important role in shaping plankton community composition by establishing unique nutrient delivery regimes favoring specific phytoplankton functional traits. The spatiotemporal scales of these regimes vary from intermittent localized nutrient bursts lasting a few days in the island wake areas to consistent high concentrations of nutrients sustained over several months over tens of kilometers in the Equatorial Undercurrent upwelling zone. To achieve deeper understanding of the bottom-up controls on primary productivity, we will integrate observations from a vertical profiling platform, along with experimental measurements from multiple groups of phytoplankton cultures recently isolated from areas associated with upwelling, island wakes and internal tides into a modeling framework to characterize the biological response to different nutrient delivery modes.  Establishing the link between physical processes and biological response will enhance our understanding of the resilience of the Galápagos Archipelago marine ecosystem in the face of climate change.

Presentation Preference: Poster

Primary Presenter: Margarita Lankford, University of North Carolina at Chapel Hill (mlankford@unc.edu)

Authors:

Margarita Lankford, University of North Carolina at Chapel Hill  (mlankford@unc.edu)

Adrian Marchetti, University of North Carolina at Chapel Hill  (amarchet@email.unc.edu)

Harvey Seim, University of North Carolina at Chapel Hill  (hseim@email.unc.edu)

Prisca Lim, University of North Carolina at Chapel Hill  (prisca@live.unc.edu)

Abigail Lamoutte, University of North Carolina at Chapel Hill  (alamoutte@unc.edu)