UVP INVESTIGATION OF BIOTIC AND ABIOTIC FACTORS ON PARTICLE FLUX IN THE SARGASSO SEA

The production and sinking of particulate organic carbon (POC) are important biogeochemical processes in marine systems. Understanding the transformations of this organic matter requires an evaluation of both the biotic and abiotic factors that affect particle creation and alteration. Prior research conducted at the Bermuda Atlantic Time-series Study (BATS) station has demonstrated that different particle types vary seasonally in their contribution to POC flux and are influenced by local zooplankton communities. A vertically and temporally detailed understanding of how environmental variables, such as temperature, water density, and chlorophyll concentrations, mediate particle flux, abundance, and morphology remains lacking. This study explores Underwater Vision Profiler (UVP) images collected on monthly oceanographic cruises near the BATS station. From May 2022 to June 2023, we analyzed images of aggregates, cylindrical fecal pellets, and spherical fecal pellets and simultaneously collected environmental data. Particle abundance and vertical distribution vary with temperature and surface chlorophyll, while there was a seasonally apparent midwater peak in particles (near 500 m) that correlates with a region of known migrator biomass. The relative contributions of particle type, optical transparency, and inferred density also change with depth. This work thus provides seasonally and vertically resolved insight into both the abiotic and biotic factors shaping the flux at BATS.

Presentation Preference: Either

Primary Presenter: Andrea Brenner, Arizona State University (aebrenne@asu.edu)

Authors:

Anne-Camille Haziza, Bermuda Institute of Ocean Sciences/ Bermuda High School  (AHaziza@bhs.bm)

Leocadio Blanco-Bercial, Arizona State University/ Bermuda Institute of Ocean Sciences  (leocadio@asu.edu)

Amy Maas, Arizona State University/ Bermuda Institute of Ocean Sciences  (amy.maas@asu.edu)