Beaufort Sea Upwelling and Corresponding Shifts in the Eukaryotic Community

Sveinn V Einarsson1, Dreux Chappell2, Kimberly Powell3, Kate E Lowry4, Robert S Pickart4 and Carin J Ashjian5, (1)Old Dominion University, Ocean, Earth, and Atmospheric Sciences, Norfolk, VA, United States, (2)Old Dominion University, Ocean, Earth and Atmospheric Sciences, Norfolk, VA, United States, (3)Old Dominion University, Ocean, Earth & Atmospheric Sciences, Norfolk, VA, United States, (4)Woods Hole Oceanographic Institution, Woods Hole, MA, United States, (5)Woods Hole Oceaonographic Institution, Woods Hole, MA, United States
Abstract:
Upwelling along continental shelves brings deeper water masses having higher nutrient concentrations up to the surface ocean. These events are known to support seasonal blooms of phytoplankton, important primary producers at the base of the oceanic food web. The Beaufort Sea regularly experiences upwelling due to atmospheric sea level pressure differences between air masses over the Canada Basin (high pressure) and the Aleutian area (low pressure) leading to easterly winds. Wind driven upwelling in the Beaufort Sea is becoming more frequent, and a completed cruise (SKQ201713S) examined the wind driven upwelling system in the Beaufort Sea during the fall season. Samples from upwelling plume transects were collected before, during, and after the events. DNA was extracted, amplified using the 18S Earth Microbiome Project primers, and sequenced, allowing us to examine the changes in the eukaryotic phytoplankton community. A specific focus of the analysis is on how the community composition shifted between diatoms and dinoflagellates in response to upwelling events. This is of particular interest as one of the dinoflagellates that was observed, Alexandrium tamarense, is associated with release of the toxin known to cause paralytic shellfish poisoning.