University of Tasmania
Browse

File(s) under permanent embargo

The physiological response to increased temperature in over-wintering sea ice algae and phytoplankton in McMurdo Sound, Antarctica and Tromsø Sound, Norway

journal contribution
posted on 2023-05-17, 12:58 authored by Martin, A, Andrew McMinnAndrew McMinn, Heath, M, Hegseth, EN, Ryan, KG
The physiological response to increased temperature during dark exposure was examined in phytoplankton and sea ice algae that had overwintered in McMurdo Sound, Antarctica and Tromsø Sound, Norway. Under ice phytoplankton and sea ice algae from McMurdo Sound were incubated in the dark for 22 days and 23 days respectively at −2, 4 and 10 °C, while phytoplankton from Tromsø Sound were incubated for 35 days at 4, 10 and 20 °C. A fluorescence approach was used to examine algal photophysiology (Fv/Fm, rETRmax and α) and changes in the concentration of chlorophyll a, while the spectrophotometric 2,4,6-tripyridyl-s-triazine (TPTZ) assay was used to quantify water-extractable carbohydrates. Prior to incubation, the photosynthetic parameters documented relatively healthy overwintering communities for both polar regions. Elevated temperature had a considerable impact on the dark survival of Arctic phytoplankton, and, to a lesser extent, Antarctic sea ice algae: photosynthetic health and stored monosaccharides declined during the incubation period, particularly at the warmest temperature regimes. In contrast, the concentration of chlorophyll a and polysaccharides remained relatively constant. When Antarctic sea ice algae were subsequently exposed to low light (~ 20 μmol photons m− 2 s− 1), significant photosynthetic recovery was only observed in cultures maintained at −2 °C. A more robust response to increased temperature was observed in Antarctic phytoplankton and in general, variability between the −2 °C and 4 °C (Antarctic) and 4 °C and 10 °C (Arctic) temperature regimes was minimal, which suggests that increasing temperature will not limit the ability of phytoplankton to survive the polar winter and provide the inocula for bloom events.

Funding

Australian Research Council

History

Publication title

Journal of Experimental Marine Biology and Ecology

Volume

428

Pagination

57-66

ISSN

0022-0981

Department/School

Institute for Marine and Antarctic Studies

Publisher

Elsevier Science Bv

Place of publication

Po Box 211, Amsterdam, Netherlands, 1000 Ae

Rights statement

Copyright 2012 Elsevier B.V.

Repository Status

  • Restricted

Socio-economic Objectives

Biodiversity in Antarctic and Southern Ocean environments

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC