Changes in nematode communities in different physiographic sites of the condor seamount (north-East atlantic ocean) and adjacent sediments

PLoS One. 2014 Dec 26;9(12):e115601. doi: 10.1371/journal.pone.0115601. eCollection 2014.

Abstract

Several seamounts are known as 'oases' of high abundances and biomass and hotspots of biodiversity in contrast to the surrounding deep-sea environments. Recent studies have indicated that each single seamount can exhibit a high intricate habitat turnover. Information on alpha and beta diversity of single seamount is needed in order to fully understand seamounts contribution to regional and global biodiversity. However, while most of the seamount research has been focused on summits, studies considering the whole seamount structure are still rather poor. In the present study we analysed abundance, biomass and diversity of nematodes collected in distinct physiographic sites and surrounding sediments of the Condor Seamount (Azores, North-East Atlantic Ocean). Our study revealed higher nematode biomass in the seamount bases and values 10 times higher in the Condor sediments than in the far-field site. Although biodiversity indices did not showed significant differences comparing seamount sites and far-field sites, significant differences were observed in term of nematode composition. The Condor summit harboured a completely different nematode community when compared to the other seamount sites, with a high number of exclusive species and important differences in term of nematode trophic diversity. The oceanographic conditions observed around the Condor Seamount and the associated sediment mixing, together with the high quality of food resources available in seamount base could explain the observed patterns. Our results support the hypothesis that seamounts maintain high biodiversity through heightened beta diversity and showed that not only summits but also seamount bases can support rich benthic community in terms of standing stocks and diversity. Furthermore functional diversity of nematodes strongly depends on environmental conditions link to the local setting and seamount structure. This finding should be considered in future studies on seamounts, especially in view of the potential impacts due to current and future anthropogenic threats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aquatic Organisms / physiology*
  • Atlantic Ocean
  • Biodiversity*
  • Biomass*
  • Geologic Sediments
  • Nematoda / physiology*

Grants and funding

This study was funded by the CONDOR project (Observatory for long term study and monitoring of Azorean ecosystem, EEA Grants PT0040/2008, (Iceland, Liechtenstein), the Fundação para a Ciência e Tecnologia, Portugal (FCT Project BIOMOUNT, PTDC/MAR/105486/2008, COMPETE/FEDERE funds). IMAR-DOP/UAz is Research and Development Unit no. 531 and LARSyS-Associated Laboratory no. 9 funded by the Portuguese Foundation for Science and Technology (FCT) through FCT - Pest/OE/EEI/LA0009/2011-2014 and by the Azores Fund for Science and Technology (FRCT), funded by OE, COMPETE, QREN and ProConvergencia. The Open Access of this paper is funded by FCT -Pest/OE/EEI/LA0009/2014 (OE, COMPETE and QREN). DZ was partly supported by the “Laboratoire d'Excellence” LabexMER (ANR-10-LABX-19), co-funded by a grant from the French government under the program “Investissements d'Avenir” by a grant from the Regional Council of Brittany (SAD programme), and by the project “Deep-sea hYdrothermal Vent nematodes as potential source of new Antibiotics” (DYVA) funded by Fondation Total and Ifremer. LB was supported by the RITMARE flagship project 2012-2016 funded by MIUR and coordinated by CNR, Italy. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.