TY - JOUR

T1 - Improving the paleoceanographic proxy tool kit – On the biogeography and ecology of the sea ice-associated species Fragilariopsis oceanica, Fragilariopsis reginae-jahniae and Fossula arctica in the northern North Atlantic

AU - Weckström, Kaarina

AU - Roche, Benjamin Redmond

AU - Miettinen, Arto

AU - Krawczyk, Diana

AU - Limoges, Audrey

AU - Juggins, Steve

AU - Ribeiro, Sofia

AU - Heikkilä, Maija

N1 - Funding Information: We would like to acknowledge the following funders: Academy of Finland (Project 307282 ); Grønlands Forskningsråd and Greenland Institute of Natural Resources for funding the project ‘Sea ice during Holocene’, which supported the collection of the West Greenland surface sediment dataset during the annual survey with M/T Paamiut. Publisher Copyright: © 2020 The Authors

PY - 2020

Y1 - 2020

N2 - A long-term perspective is essential for understanding environmental change. To be able to access the past, environmental archives such as marine and lake sediments that store information in the form of diverse proxy records are used. Whilst many analytical techniques exist to extract the information stored in these proxy records, the critical assessment and refinement of current methods in addition to developing new methods is crucial to improving our understanding. This study aims to improve our knowledge on diatom species used for reconstructing ocean surface conditions, especially temperature and sea ice variability over time. We define the distribution and the relationship to sea surface temperature (SST) and sea ice concentrations (SIC) of the species Fragilariopsis oceanica, Fragilariopsis reginae-jahniae and Fossula arctica using diatom training sets from the northern North Atlantic. We further assess the effect of separating these species compared to grouping them under F. oceanica, as has been done in the past. Our results suggest that while these three species share similarities such as the preference for stratified waters induced by sea ice or glacier meltwater, they also exhibit heterogeneous distributions across the northern North Atlantic, with individual optima for SST and SIC. This also affects quantitative reconstructions based on our data, resulting in lower SST and higher SIC estimates when the species are separated in the surface sediment and down-core diatom assemblages.

AB - A long-term perspective is essential for understanding environmental change. To be able to access the past, environmental archives such as marine and lake sediments that store information in the form of diverse proxy records are used. Whilst many analytical techniques exist to extract the information stored in these proxy records, the critical assessment and refinement of current methods in addition to developing new methods is crucial to improving our understanding. This study aims to improve our knowledge on diatom species used for reconstructing ocean surface conditions, especially temperature and sea ice variability over time. We define the distribution and the relationship to sea surface temperature (SST) and sea ice concentrations (SIC) of the species Fragilariopsis oceanica, Fragilariopsis reginae-jahniae and Fossula arctica using diatom training sets from the northern North Atlantic. We further assess the effect of separating these species compared to grouping them under F. oceanica, as has been done in the past. Our results suggest that while these three species share similarities such as the preference for stratified waters induced by sea ice or glacier meltwater, they also exhibit heterogeneous distributions across the northern North Atlantic, with individual optima for SST and SIC. This also affects quantitative reconstructions based on our data, resulting in lower SST and higher SIC estimates when the species are separated in the surface sediment and down-core diatom assemblages.

KW - Biogeography

KW - Diatoms

KW - Ecology

KW - Indicator species

KW - Northern North Atlantic

KW - Sea ice reconstruction

U2 - 10.1016/j.marmicro.2020.101860

DO - 10.1016/j.marmicro.2020.101860

M3 - Journal article

AN - SCOPUS:85082755416

VL - 157

JO - Marine Micropaleontology

JF - Marine Micropaleontology

SN - 0377-8398

M1 - 101860

ER -