Mega-blooms of the harmful alga Alexandrium catenella in the Bering Sea recorded by the Continuous Plankton Recorder Survey.

Authors

Clare Ostle, Keelan C Lawlor, Sonia D Batten, Martina Brunetta, Michael Cunliffe, Claire H Davies, Glenn M Harper, David G Johns, Hannah Robinson, Francesca Loro, John Nelson, Anthony J Richardson, Akash Sastri, Marrianne Wootton, Sarah Zimmermann, Rowena Stern-Kluckner

Published in

Harmful algae. Volume 159. Pages 103194. Epub Aug 06, 2026.

Abstract

The Pacific Arctic region is warming faster than almost any other region on Earth, and reductions in sea ice extent and the increased northward transport of warmer Pacific-origin water are expected to favour the poleward expansion of harmful algal blooms (HABs). The dinoflagellate Alexandrium catenella produces paralytic shellfish toxins (PSTs) that accumulate through marine food webs, and recent recurring blooms in the Chukchi Sea have been linked to wildlife mortality and risk to subsistence harvesters. Offshore monitoring in this remote region is sparse. Using the Continuous Plankton Recorder (CPR) Survey, we describe four Alexandrium bloom events sampled along a transect in the Bering Sea between 2021 and 2024, including the largest Alexandrium bloom recorded in the >60-year history of the CPR Survey (750,000 cells per 10 nautical-mile sample, July 2023). DNA was extracted from formalin-preserved CPR silks using three protocols, and partial large subunit (LSU) rDNA sequencing identified the cells as A. catenella. Bloom peaks occurred in shelf waters near the Pribilof Islands and St. Matthew Island, within Bering Summer Water (∼32 salinity, ∼9°C). The findings extend the known offshore distribution of potentially toxic A. catenella in the eastern Bering Sea, demonstrate the value of the CPR Survey as a cost-effective platform for HAB monitoring in difficult-to-access waters, and add to growing evidence that warming is increasing HAB risk to ecosystem function and food security in the Pacific Arctic.

PMID:
42702412
Bibliographic data and abstract were imported from PubMed on 07 Sep 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.