Comparing marine primary production estimates through different methods and development of conversion equations

Abstract

Numerous studies have compared the rates of primary production using various techniques at specific locations and times. However, these comparisons are local and cannot be used to compare or scale rates of primary production using different methods across ocean basins or seasonal time scales. Here, we quantify the range in rates of primary production derived using different techniques and provide equations that allow conversions of estimates between different methods. We do so on the basis of a compilation of data on volumetric estimates of primary production rates concurrently estimated with at least two different methods. We observed that the comparison of estimates of marine phytoplankton primary production derived from different methods reveals very large variations between methods. The highest primary production estimates are derived using the 18 O method, which may provide the best and more generally applicable estimate of gross primary production (GPP). The regression equations presented in this work provide the best available approach to convert data across methods and therefore integrate and synthesize available and future data derived using different methods.

Ocean acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO<sub>2</sub> tolerance in phytoplankton productivity

“…Dring and Jewson, 1982;González et al, 2008;Regaudie-de Gioux et al, 2014). Samples were analysed for total organic carbon (TO 14 C) content, thereby including any 14 C-labelled photosynthate leaked to the dissolved organic carbon (DO 14 C) pool (Regaudie-de Gioux et al, 2014).…”

“…Deppeler et al: Ocean acidification of a coastal Antarctic marine microbial community of which 40 % has been via the SO (Raven and Falkowski, 1999;Sabine et al, 2004;Khatiwala et al, 2009;Takahashi et al, 2009Takahashi et al, , 2012Frölicher et al, 2015). While ameliorating CO 2 accumulation in the atmosphere, increasing oceanic CO 2 uptake alters the chemical balance of surface waters, with the average pH having already decreased by 0.1 units since pre-industrial times (Sabine et al, 2004;Raven et al, 2005). If anthropogenic emissions continue unabated, future concentrations of CO 2 in the atmosphere are projected to reach ∼ 930 µatm by 2100 and peak at ∼ 2000 µatm by 2250 (Meinshausen et al, 2011;IPCC, 2013).…”

The influence of phytoplankton pigments composition and dominant cell size on fluorescence-derived photophysiological parameters and implications for primary production rates

“…Other methods to quantify the end products of photosynthesis have been applied, based on stable isotope additions, using the labelled 13 C and 18 O as tracers (see Regaudie-de-Gioux et al 2014). The different methods and measurement protocols, such as incubation time, will provide rates of gross or net primary production.…”

“…Furthermore, there are still limitations regarding the results analysis, mostly associated with the uncertainties in the respiration and other metabolic rates (Bender et al 1999;Williams et al 2002). The respiration during incubation periods can effectively recycle fixed CO2 depending on the incubation time, thus preventing the accurate discrimination of gross from net primary production rates (Marra 2002;Regaudie-de-Gioux et al 2014). …”

“…Both ocean color and fluorimetric approaches easily estimate chlorophyll concentrations as a proxy for phytoplankton abundance, which despite of its important prediction power for photosynthetic parameters (Huot et al 2007b) cannot account alone for primary production rates, especially over large scales (e.g., Saba et al 2011). Primary production classic techniques are expensive and time-consuming limiting, thus, temporal and spatial coverage (see Regaudie-de-Gioux et al 2014).…”