Antarctic coastal microalgal primary production and photosynthesis
McMinn, A.; Ashworth, C.; Bhagooli, R.; Martin, A.; Salleh, S.; Ralph, P.; Ryan, K. (2012). Antarctic coastal microalgal primary production and photosynthesis. Mar. Biol. (Berl.) 159(12): 2827-2837. http://dx.doi.org/10.1007/s00227-012-2044-0
In: Marine Biology: International Journal on Life in Oceans and Coastal Waters. Springer: Heidelberg; Berlin. ISSN 0025-3162; e-ISSN 1432-1793, more
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| Authors | | Top |
- McMinn, A.
- Ashworth, C.
- Bhagooli, R.
- Martin, A.
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- Salleh, S.
- Ralph, P.
- Ryan, K.
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| Abstract |
Primary production in coastal Antarctica is primarily contributed from three sources: sea ice algae, phytoplankton, and microphytobenthos. Compared to other eastern Antarctic sites, the sea ice microalgal biomass at Casey Station, in spring 2005 was relatively low, 3.84 ± 1.67 to 21.6 ± 13.3 mg chl-a m-2 but productive, 103–163 mg C m-2 day-1. The photosynthetic parameters, F v/F m and rETRmax, imply a community well-acclimated to the light climate of the benthic, water column, and sea ice habitats. Phytoplankton biomass was greatest in late spring (11.1 ± 0.920 µg chl-a l-1), which probably reflects input from the overlying sea ice. Lower biomass and depressed F v/F m values later in the season were probably due to nutrient limitation. Benthic microalgal biomass was consistently between 200 and 400 mg chl-a m-2 and production increased through into late summer (204 mg C m-2 day-1). After the sea ice broke out, the marine environment supported a small phytoplankton biomass and a large benthic microalgal biomass. Compared with previous studies, F v/F m values were relatively low but there was no evidence of photoinhibition. When sea ice was present, primary production of benthic microalgae was either very low or there was a net draw down of oxygen. The benthic microalgal community made a larger contribution to total primary production than the phytoplankton or sea ice algae at water depth less than approximately 5 m. |
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