Life on the ice-edge: Paleoenvironmental significance of the radiolarian species Amphimelissa setosa in the northern hemisphere ...

• Main Authors: Hernández-Almeida, Iván, Björklund, Kjell R., Diz, Paula, Kruglikova, Svetlana, Ikenoue, Takahito, Matul, Alexander, Saavedra-Pellitero, Mariem, Swanberg, Neil
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2020
• Subjects: Radiolaria; Amphimelissa setosa; Ice-edge; Northern Hemisphere; Paleoecology; Proxy; Arctic Basin; Arctic; Chukchi; Chukchi Sea; North Atlantic; Sea ice
• Online Access: https://dx.doi.org/10.3929/ethz-b-000441351; http://hdl.handle.net/20.500.11850/441351

The high-latitude Northern Hemisphere is a key region in the global climate balance. Variations in sea-ice extent affect biological productivity, CO2 exchange and carbon drawdown. Marine proxies indicative of proximity of the ice-marginal zone are therefore essential to understand these processes. Amphimelissa setosa is nowadays a dominant radiolarian species in the Arctic basin and very abundant in the high-latitude North Atlantic. This species, now absent from the North Pacific, has been widely used as a qualitative proxy of modern and past environmental conditions in the high-latitude Northern Hemisphere. Using our new and published data on the distribution of A. setosa in plankton, sediment trap, surface sediment and downcore samples, we provide a quantitative ecological context for the occurrence of this species. We find that the optimal depth and season of A. setosa in the modern North Atlantic and the Chukchi Sea are 160 m and the late boreal summer/early fall (August–October), respectively. A ... : Quaternary Science Reviews, 248 ...