Photosynthetic response and recovery of Antarctic marine benthic microalgae exposed to elevated irradiances and temperatures

• Published in: Polar Biology
• Main Authors: Salleh, S, McMinn, A
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer-Verlag 2011
• Subjects: Biological Sciences; Ecology; Marine and estuarine ecology (incl. marine ichthyology); Antarctic; Antarc*; Antarctica; Polar Biology
• Online Access: https://doi.org/10.1007/s00300-010-0943-4; http://ecite.utas.edu.au/75592

Exposure to high temperatures affects thephotosynthetic processes in marine benthic microalgae bylimiting the transport of electrons, thus reducing the abilityof the cell to use light. This causes damage to the PhotosystemII (PSII) and may lead to photoinhibition. However,the PSII of benthic microalgal communities from BrownBay, eastern Antarctica, were relatively unaffected bysignificant changes in temperature. Benthic microalgaeexposed to temperatures up to 8Celsius degree and an irradiance of450 lmol photons m-2 s-1 did not experience any photosyntheticdamage or irreversible photoinhibition. Theeffective quantum yield (DF/Fm0) at 8Celsius degree (0.433 +- 0.042)was higher by comparison to cell incubated at -0.1 Celsius degree(0.373 +- 0.015) with similar irradiances. Temperaturesdown to -5 Celsius degree at a similar irradiance showed a decrease inphotosynthesis with decreasing temperature, but no severephotoinhibition as the cells were able to dissipate excessenergy via non-photochemical quenching and recover fromdamage. These responses are consistent with those recordedin past studies on Antarctic benthic microalgae andsuggest that short-term temperature change (from -5 to8 Celsius degree) will not do irreversible damage to the PSII and willnot affect the photosynthesis of the benthic microalgae.