The Influence of Temporal Variability on Marine Snow Dynamics in a Subtropical Estuary System

Elizabeth Harvey, University of New Hampshire, Department of Biological Sciences, Durham, United States, Sean Anderson, Skidaway Institute of Oceanography at the University of Georgia, Marine Sciences, Savannah, GA, United States and Patrick Duffy, Skidaway Institute of Oceanography at the University of Georgia, United States
Abstract:
Particle aggregation aided by transparent exopolymer particles (TEP) is one of the most common mechanisms that facilitates vertical carbon flux. Given TEP is a fundamental link between dissolved and particulate carbon pools, understanding the mechanisms that mediate TEP dynamics will enhance models of carbon flow in the ocean. Most TEP surveys have been conducted under a spatial context, often sampled along a horizontal or vertical gradient, while temporal TEP dynamics have been less examined. Here, TEP concentrations and production dynamics were measured over varying time scales (from hourly to weekly) from stationary geographic locations in the Skidaway River Estuary in Savannah, Georgia. Interestingly, distinct patterns in TEP concentration were observed over diel scales, with peak TEP occurring following sunset. Significant differences in TEP concentration were also observed over the tidal cycle, with higher TEP:Chl a ratios almost universally observed at high tide. Trends across weekly time scales were hard to resolve, but temperature emerged as an important factor influencing TEP concentrations. Finally, the role of temporal variability on TEP consumption and production dynamics will be discussed. Overall, these findings highlight the importance of considering how TEP shifts over time, especially in dynamic coastal systems where environmental factors often fluctuate.