TY - JOUR
T1 - Evidence for the Impact of Climate Change on Primary Producers in the Southern Ocean
AU - Pinkerton, Matthew H.
AU - Boyd, Philip W.
AU - Deppeler, Stacy
AU - Hayward, Alex
AU - Höfer, Juan
AU - Moreau, Sebastien
N1 - Publisher Copyright:
© Copyright © 2021 Pinkerton, Boyd, Deppeler, Hayward, Höfer and Moreau.
PY - 2021/5/17
Y1 - 2021/5/17
N2 - Within the framework of the Marine Ecosystem Assessment for the Southern Ocean (MEASO), this paper brings together analyses of recent trends in phytoplankton biomass, primary production and irradiance at the base of the mixed layer in the Southern Ocean and summarises future projections. Satellite observations suggest that phytoplankton biomass in the mixed-layer has increased over the last 20 years in most (but not all) parts of the Southern Ocean, whereas primary production at the base of the mixed-layer has likely decreased over the same period. Different satellite models of primary production (Vertically Generalised versus Carbon Based Production Models) give different patterns and directions of recent change in net primary production (NPP). At present, the satellite record is not long enough to distinguish between trends and climate-related cycles in primary production. Over the next 100 years, Earth system models project increasing NPP in the water column in the MEASO northern and Antarctic zones but decreases in the Subantarctic zone. Low confidence in these projections arises from: (1) the difficulty in mapping supply mechanisms for key nutrients (silicate, iron); and (2) understanding the effects of multiple stressors (including irradiance, nutrients, temperature, pCO2, pH, grazing) on different species of Antarctic phytoplankton. Notwithstanding these uncertainties, there are likely to be changes to the seasonal patterns of production and the microbial community present over the next 50–100 years and these changes will have ecological consequences across Southern Ocean food-webs, especially on key species such as Antarctic krill and silverfish.
AB - Within the framework of the Marine Ecosystem Assessment for the Southern Ocean (MEASO), this paper brings together analyses of recent trends in phytoplankton biomass, primary production and irradiance at the base of the mixed layer in the Southern Ocean and summarises future projections. Satellite observations suggest that phytoplankton biomass in the mixed-layer has increased over the last 20 years in most (but not all) parts of the Southern Ocean, whereas primary production at the base of the mixed-layer has likely decreased over the same period. Different satellite models of primary production (Vertically Generalised versus Carbon Based Production Models) give different patterns and directions of recent change in net primary production (NPP). At present, the satellite record is not long enough to distinguish between trends and climate-related cycles in primary production. Over the next 100 years, Earth system models project increasing NPP in the water column in the MEASO northern and Antarctic zones but decreases in the Subantarctic zone. Low confidence in these projections arises from: (1) the difficulty in mapping supply mechanisms for key nutrients (silicate, iron); and (2) understanding the effects of multiple stressors (including irradiance, nutrients, temperature, pCO2, pH, grazing) on different species of Antarctic phytoplankton. Notwithstanding these uncertainties, there are likely to be changes to the seasonal patterns of production and the microbial community present over the next 50–100 years and these changes will have ecological consequences across Southern Ocean food-webs, especially on key species such as Antarctic krill and silverfish.
KW - Antarctica
KW - MODIS
KW - SeaWiFS
KW - biogeochemistry
KW - climate
KW - deep chlorophyll maximum
KW - ocean colour
KW - phytoplankton
UR - http://www.scopus.com/inward/record.url?scp=85107039905&partnerID=8YFLogxK
U2 - 10.3389/fevo.2021.592027
DO - 10.3389/fevo.2021.592027
M3 - Article
AN - SCOPUS:85107039905
SN - 2296-701X
VL - 9
JO - Frontiers in Ecology and Evolution
JF - Frontiers in Ecology and Evolution
M1 - 592027
ER -