Large diatom bloom off the Antarctic Peninsula during cool conditions associated with the 2015/2016 El Niño

• Published in: Communications Earth & Environment
• Main Authors: Costa, Raul Rodrigo, Mendes, Carlos Rafael Borges, Ferreira, Afonso, Tavano, Virginia Maria, Dotto, Tiago Segabinazzi, Secchi, Eduardo Resende
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2021
• Subjects: Antarctic; Antarctic Peninsula; The Antarctic; Antarc*; Sea ice
• Online Access: https://ueaeprints.uea.ac.uk/id/eprint/82738/; https://ueaeprints.uea.ac.uk/id/eprint/82738/1/Published_Version.pdf; https://doi.org/10.1038/s43247-021-00322-4

Diatoms play crucial functions in trophic structure and biogeochemical cycles. Due to poleward warming, there has been a substantial decrease in diatom biomass, especially in Antarctic regions that experience strong physical changes. Here we analyze the phytoplankton contents of water samples collected in the spring/summer of 2015/2016 off the North Antarctic Peninsula during the extreme El Niño event and compare them with corresponding satellite chlorophyll-a data. The results suggest a close link between large diatom blooms, upper ocean physical structures and sea ice cover, as a consequence of the El Niño effects. We observed massive concentrations (up to 40 mg m–3 of in situ chlorophyll-a) of diatoms coupled with substantially colder atmospheric and oceanic temperatures and high mean salinity values associated with a lower input of meltwater. We hypothesize that increased meltwater concentration due to continued atmospheric and oceanic warming trends will lead to diatom blooms becoming more episodic and spatially/temporally restricted.