Alexandrium on the Alaskan Beaufort Sea shelf: Impact of upwelling in a warming Arctic.

Autor: Einarsson SV; Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, USA., Lowry KE; Science Philanthropy Alliance, Palo Alto, CA, USA; Woods Hole Oceanographic Institution, Woods Hole, MA, USA., Lin P; Woods Hole Oceanographic Institution, Woods Hole, MA, USA., Pickart RS; Woods Hole Oceanographic Institution, Woods Hole, MA, USA., Ashjian CJ; Woods Hole Oceanographic Institution, Woods Hole, MA, USA., Chappell PD; Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, USA. Electronic address: pdchappe@odu.edu.
Jazyk: angličtina
Zdroj: Harmful algae [Harmful Algae] 2022 Dec; Vol. 120, pp. 102346. Date of Electronic Publication: 2022 Nov 18.
DOI: 10.1016/j.hal.2022.102346
Abstrakt: The harmful algal genus Alexandrium has characteristically been found in temperate and subtropical regions; however recent evidence suggests global warming may be expanding its range into high latitude waters. Alexandrium cysts have previously been documented in the Chukchi Sea and we hypothesize that Alexandrium may be expanding further into the Arctic due to distribution by the Beaufort shelfbreak jet. Here we document the presence of Alexandrium catenella along the Alaskan Beaufort Sea shelf, marking an expansion of its known range. The observations of A. catenella were made using three different methods: FlowCAM imaging, 18S eukaryotic sequencing, and real-time quantitative PCR. Four occupations of a shelf/slope transect spanned the evolution of a strong wind-driven upwelling event over a 5-day period. A nearby mooring provided the physical context for the event, revealing that enhanced easterly winds reversed the Beaufort shelfbreak jet to the west and induced upwelling of colder, denser water onto the outer shelf. A. catenella sequences dominated the surface phytoplankton community at the onset of the upwelling event. This signal vanished during and after the event, likely due to a combination of alongstream advection, cross-stream advection, and wind mixing. These results suggest contrasting physical processes that are both subject to global warming amplification, delivery of warm waters via the Beaufort shelfbreak jet and upwelling, may control the proliferation of this potential harmful alga into the Arctic.
Competing Interests: Declaration of Competing Interest The authors declare no competing interests.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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