The effect of prolonged darkness on the growth, recovery and survival of Antarctic sea ice diatoms

• Main Authors: Reeves, S, Andrew McMinn, Martin, AR
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2011
• Subjects: Marine and estuarine ecology (incl. marine ichthyology); Winter Antarctic sea ice algae phytoplankton dark survival; Antarctic; The Antarctic; Antarc*; Antarctica; ice algae; Sea ice
• Online Access: https://figshare.com/articles/journal_contribution/The_effect_of_prolonged_darkness_on_the_growth_recovery_and_survival_of_Antarctic_sea_ice_diatoms/22888559

While global climate change in polar regions is expected to cause significant warming, the annual cycle of light and dark will remain unchanged. Cultures of three species of Antarctic sea ice diatoms, Fragilariopsis cylindrus (Grunow) Krieger, Thalassiosira antarctica Comber and Entomoneis kjellmanii (P.T. Cleve) Poulin and Cardinal, were incubated in the dark and exposed to differing temperatures. Maximum dark survival times varied between 30 and 60 days. Photosynthetic parameters, photosynthetic efficiency (a), maximum quantum yield (Fv/ Fm), maximum relative electron transport rate (rETRmax) and non-photochemical quenching (NPQ), showed that dark exposure had a significant impact on photoacclimation. In contrast, elevated temperatures had a relatively minor impact on photosynthetic functioning during the dark exposure period but had a considerable impact on dark survival with minimal dark survival times reduced to only 7 days when exposed to 10 Celsius degree. Recovery of maximum quantum yield of fluorescence (Fv/Fm) was not significantly impacted by temperature, species or dark exposure length. Recovery rates of Fv/Fm ranged from -5.06E- 7 +- 2.71E-7 s-1 to 1.36E-5 +- 1.53E-5 s-1 for monthly experiments and from -9.63E-7 +- 7.71E-7 s-1 to 2.65E-5 +- 2.97E-5 s-1 for weekly experiments. NPQ recovery was greater and more consistent than Fv/Fm recovery, ranging between 5.74E-7 +- 8.11E-7 s-1 to 7.50E-3 +- 7.1E-4 s-1. The concentration of chl-a and monosaccharides remained relatively constant in both experiments. These results suggest that there will probably be little effect on Antarctic microalgae with increasing water temperatures during the Antarctic winter.