MAREDAT: towards a world atlas of MARine Ecosystem DATa

Abstract

Abstract. We present a summary of biomass data for 11 plankton functional types (PFTs) plus phytoplankton pigment data, compiled as part of the MARine Ecosystem biomass DATa (MAREDAT) initiative. The goal of the MAREDAT initiative is to provide, in due course, global gridded data products with coverage of all planktic components of the global ocean ecosystem. This special issue is the first step towards achieving this. The PFTs presented here include picophytoplankton, diazotrophs, coccolithophores, Phaeocystis, diatoms, picoheterotrophs, microzooplankton, foraminifers, mesozooplankton, pteropods and macrozooplankton. All variables have been gridded onto a World Ocean Atlas (WOA) grid (1 • × 1 • × 33 vertical levels × monthly climatologies). The results show that abundance is much better constrained than their carbon content/elemental composition, and coastal seas and other high productivity regions have much better coverage than the much larger volumes where biomass is relatively low. The data show that (1) the global total heterotrophic biomass (2.0-4.6 Pg C) is at least as high as the total autotrophic biomass (0.5-2.4 Pg C excluding nanophytoplankton and autotrophic dinoflagellates); (2) the biomass of zooplankton calcifiers (0.03-0.67 Pg C) is substantially higher than that of coccolithophores (0.001-0.03 Pg C); (3) patchiness of biomass distribution increases with organism size; and (4) although zooplankton biomass measurements below 200 m are rare, the limited measurements available suggest that Bacteria and Archaea are not the only important heterotrophs in the deep sea. More data will be needed to characterise ocean ecosystem functioning and associated biogeochemistry in the Southern Hemisphere and below 200 m. Future efforts to understand marine ecosystem composition and functioning will be helped both by further archiving of historical data and future sampling at new locations.Microzooplankton database:

Intercomparison of Ocean Color Algorithms for Picophytoplankton Carbon in the Ocean

“…One of them is that it is only composed of picophytoplankton: though they are important contributors to the open-ocean phytoplankton biomass, picophytoplankton form a decreasing proportion of the phytoplankton biomass in more productive waters, where larger cells tend to become more important (Marañón et al, 2012;Marañón, 2015). One interesting avenue would be to expand the database with other phytoplankton groups (Buitenhuis et al, 2013;Sal et al, 2013). Nanoplankton can also be counted using flow cytometry, and microphytoplankton groups counted using microscope or automated image processing (Sosik and Olson, 2007;Álvarez et al, 2012), but the relationship between carbon and abundance becomes more variable for larger and more irregularly-shaped phytoplankton (Moberg and Sosik, 2012;Saccà, 2016).…”

“…Algorithm D (Martínez-Vicente et al, 2013) is another semi-empirical algorithm, developed from the relationship between in situ flow cytometry-based carbon and b bp (470), but is included in the comparison with some changes. The first modification was to re-compute the coefficients in the original equation by using the same computation of picoplankton as the one used in this work, which meant ignoring the nanoeukaryotes, cryptophytes and coccolithophorids contributions to the picoplankton carbon and use the same carbon to cell conversion factors as in this study (i.e., those of MAREDAT; Buitenhuis et al, 2013). This recalculation led to lower (pico)phytoplankton carbon estimates which were, on average, 27% less than the published values of phytoplankton carbon (from pico-and nano-plankton) used in Martínez-Vicente et al (2013).…”

Diatom Phytochromes Reveal the Existence of Far-Red-Light-Based Sensing in the Ocean

“…Diatom species possessing DPH sequences were searched in the MAREDAT database (Leblanc et al, 2012;Buitenhuis et al, 2013). A total of 544 and 1274 entries about distribution information were recovered for Thalassiosira rotula and Skeletonema costatum, respectively.…”

“…time. We queried the MAREDAT (marine ecosystem data) database, which contains information about diatom abundance (Leblanc et al, 2012;Buitenhuis et al, 2013) to explore the distribution of marine diatom species bearing the DPH gene (Supplemental Data Set 4). The search identified two diatoms expressing DPH, Thalassiosira rotula and Skeletonema costatum ( Figure 5B), and revealed their wide vertical distribution along the water column, including deep-water layers.…”

Global marine plankton functional type biomass distributions: coccolithophores

“…A summary of the findings for all groups is presented in Buitenhuis et al (2013). This paper presents a database of global coccolithophore biomass distributions compiled as part of the MAREDAT effort.…”