Publication Date:
2016-04-21
Description:
Planktonic organisms play crucial roles in oceanic food webs and global biogeochemical cycles. Most of our knowledge about the ecological impact of large zooplankton stems from research on abundant and robust crustaceans, and in particular copepods. A number of the other organisms that comprise planktonic communities are fragile, and therefore hard to sample and quantify, meaning that their abundances and effects on oceanic ecosystems are poorly understood. Here, using data from a worldwide in situ imaging survey of plankton larger than 600 mum, we show that a substantial part of the biomass of this size fraction consists of giant protists belonging to the Rhizaria, a super-group of mostly fragile unicellular marine organisms that includes the taxa Phaeodaria and Radiolaria (for example, orders Collodaria and Acantharia). Globally, we estimate that rhizarians in the top 200 m of world oceans represent a standing stock of 0.089 Pg carbon, equivalent to 5.2% of the total oceanic biota carbon reservoir. In the vast oligotrophic intertropical open oceans, rhizarian biomass is estimated to be equivalent to that of all other mesozooplankton (plankton in the size range 0.2-20 mm). The photosymbiotic association of many rhizarians with microalgae may be an important factor in explaining their distribution. The previously overlooked importance of these giant protists across the widest ecosystem on the planet changes our understanding of marine planktonic ecosystems.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Biard, Tristan -- Stemmann, Lars -- Picheral, Marc -- Mayot, Nicolas -- Vandromme, Pieter -- Hauss, Helena -- Gorsky, Gabriel -- Guidi, Lionel -- Kiko, Rainer -- Not, Fabrice -- England -- Nature. 2016 Apr 28;532(7600):504-7. doi: 10.1038/nature17652. Epub 2016 Apr 20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Sorbonne Universites, UPMC Universite Paris 06, CNRS, Laboratoire Adaptation et Diversite en Milieu Marin UMR7144, Station Biologique de Roscoff, 29688 Roscoff, France. ; Sorbonne Universites, UPMC Universite Paris 06, CNRS, Laboratoire d'Oceanographie de Villefranche (LOV) UMR7093, Observatoire Oceanologique, 06230 Villefranche-sur-Mer, France. ; GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstrasse 1-3, 24148 Kiel, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/27096373" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
*Biomass
;
*Biota
;
Carbon/metabolism
;
Carbon Sequestration
;
Earth (Planet)
;
Microalgae/metabolism
;
*Oceans and Seas
;
Photosynthesis
;
Rhizaria/classification/*isolation & purification/metabolism
;
Seawater/chemistry
;
Symbiosis
;
Zooplankton/classification/*isolation & purification/metabolism
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
