Particle Flux to Abyssal Depths: Hourly to Seasonal Variability Over an Eight Month Period (October 2014–June 2015)

Crissy Huffard1, Colleen A Durkin2, Stephanie Wilson3, Paul McGill1, Richard Henthorn1 and Kenneth Smith1, (1)Monterey Bay Aquarium Research Institute, Moss Landing, CA, United States, (2)Moss Landing Marine Laboratories, Moss Landing, CA, United States, (3)Bangor University, United Kingdom
Long-duration, high temporal resolution sampling technologies are needed to resolve the rapidly changing ecological drivers of carbon export. We present detailed views of particle supply over an eight-month period (October 2014June 2015) at the abyssal time-series site Station M (northeast Pacific, ~ 4000 m depth). Using fluorescence data and macro images from the Sedimentation Event Sensor (SES), an autonomous, bottom-moored optical sediment trap with hourly measures of particle flux, we resolved timescales over which flux events occurred, their biological properties, and ecological sources. Diel variability in fluxes to 3900 meters (50 meters above bottom) was influenced by the biological source of particles and the prevailing current direction. Relative contributions of aggregates, appendicularian fecal pellets, crustacean fecal pellets, and salp fecal pellets varied during high- and low-flux periods. SES light attenuation and modeled carbon flux accurately represented the quantity of particulate material sinking to the site. We recommend using this instrument in combination with conventional sediment traps to work toward a detailed mechanistic understanding of carbon flux.