File(s) under permanent embargo
Assessing Sub-Antarctic Zone primary productivity from fast repetition rate fluorometry
journal contribution
posted on 2023-05-17, 10:14 authored by Cheah, W, Andrew McMinnAndrew McMinn, Griffiths, FB, Karen WestwoodKaren Westwood, Simon WrightSimon Wright, Molina, E, Webb, JP, van den Enden, RIn situ primary productivity(PP)in the Sub-Antarctic Zone(SAZ)and the Polar Frontal Zone (PFZ)south of Australia was estimated using fast repetition rate fluorometry(FRRF).FRRF-derived PP at Process station 3(P3)southeast of Tasmania(461S, 1531E) were higher than P1inthe southwest of Tasmania (461S, 1401E) and P2 in the Polar Frontal Zone (541S, 1461E). The FRRF-derived PP rates were well correlated with 14C-uptake rates fromone-hour incubations(r2¼0.85,slope¼1.2370.05, po0.01, n¼85) but the relationship between both methods differed vertically and spatially. There was a linear relationship between FRRF-based PP and 14C-based PP underlight-limited conditions in deeper waters. Under light-saturated conditions near the surface(0–45m),the relationship was less clear. This was likely associated with the effects of physiological processes such as cyclic electron flow and the Mehler reaction, which are stimulated at high irradiance. Our results indicate that FRRF can be used to estimate photosynthesis rates in the SAZ and PFZ but to derive an accurate estimation of C-fixation requires a detailed understanding of the physiological properties of the cells and their response to oceanographic parameters under different environmental conditions.
Funding
Department of Environment and Energy (Cwth)
History
Publication title
Deep-Sea Research. Part 2: Topical Studies in OceanographyVolume
58Issue
21-22Pagination
2179-2188ISSN
0967-0645Department/School
Institute for Marine and Antarctic StudiesPublisher
Pergamon-Elsevier Science LtdPlace of publication
The Boulevard, Langford Lane, Kidlington, Oxford, England, Ox5 1GbRights statement
The definitive version is available at http://www.sciencedirect.comRepository Status
- Restricted