PhytoBase: A global synthesis of open-ocean phytoplankton occurrences

Damiano Righetti,Nicolas Gruber,Michael D Guiry,Meike Vogt,Niklaus E Zimmermann

doi:10.5194/essd-12-907-2020

Abstract

Abstract. Marine phytoplankton are responsible for half of the global net primary production and perform multiple other ecological functions and services of the global ocean. These photosynthetic organisms comprise more than 4300 marine species, but their biogeographic patterns and the resulting species diversity are poorly known, mostly owing to severe data limitations. Here, we compile, synthesize, and harmonize marine phytoplankton occurrence records from the two largest biological occurrence archives (Ocean Biogeographic Information System, OBIS; and Global Biodiversity Information Facility, GBIF) and three independent recent data collections. We bring together over 1.36 million phytoplankton occurrence records (1.28 million at the level of species) for a total of 1704 species, spanning the principal groups of the diatoms, dinoflagellates, and haptophytes, as well as several other groups. This data compilation increases the amount of marine phytoplankton records available through the single largest contributing archive (OBIS) by 65 %. Data span all ocean basins, latitudes, and most seasons. Analyzing the oceanic inventory of sampled phytoplankton species richness at the broadest spatial scales possible using a resampling procedure, we find that richness tends to saturate at ∼93 % of all species in our database in the pantropics, at ∼64 % in temperate waters, and at ∼35 % in the cold Northern Hemisphere, while the Southern Hemisphere remains under-explored. We provide metadata on the cruise, research institution, depth, and date for each data record, and we include phytoplankton cell counts for 193 763 records. We strongly recommend consideration of spatiotemporal biases in sampling intensity and varying taxonomic sampling scopes between research cruises or institutions when analyzing the occurrence data spatially. Including such information into predictive tools, such as statistical species distribution models, may serve to project the diversity, niches, and distribution of species in the contemporary and future ocean, opening the door for quantitative macroecological analyses of phytoplankton. PhytoBase can be downloaded from PANGAEA: https://doi.org/10.1594/PANGAEA.904397 (Righetti et al., 2019a).

Highlights

Phytoplankton are photosynthetic members of the plankton realm, responsible for about half of the global net primary production (Field et al, 1998)
Additional data processed by the Tara Oceans or Malaspina expedition (Duarte, 2015) may provide valuable context for a future synthesis and may eventually combine molecular with traditional approaches, yet here we have focused on publicly available sources up to March 2017
Data density is globally highly uneven (Fig. 1b, c; histograms) with 44.7 % of all records falling into the North Atlantic alone, while only 1.4 % of records originate from the South Atlantic and large parts of the South Pacific basin are devoid of records (Fig. 1a)

Summary

Introduction

Phytoplankton are photosynthetic members of the plankton realm, responsible for about half of the global net primary production (Field et al, 1998). Additional factors that have impeded progress in developing a good biogeographic understanding of phytoplankton are difficulties in species identification, linked to their microscopic body size. This is reflected well in the current geographic knowledge of phytoplankton species richness from direct observations (e.g., RodríguezRamos et al, 2015), which is much more limited compared to that of other marine taxa, such as zooplankton (e.g., Rombouts et al, 2010), fishes (e.g, Jones and Cheung, 2015), sharks (e.g., Worm et al, 2005), or krill (e.g., Tittensor et al, 2010), even though many of these taxa suffer from deficiencies in sampling efforts (Menegotto and Rangel, 2018)

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Results

Discussion

Conclusion