Dataset Information

Elucidating Viral Communities During a Phytoplankton Bloom on the West Antarctic Peninsula.

ABSTRACT: In Antarctic coastal waters where nutrient limitations are low, viruses are expected to play a major role in the regulation of bloom events. Despite this, research in viral identification and dynamics is scarce, with limited information available for the Southern Ocean (SO). This study presents an integrative-omics approach, comparing variation in the viral and microbial active communities on two contrasting sample conditions from a diatom-dominated phytoplankton bloom occurring in Chile Bay in the West Antarctic Peninsula (WAP) in the summer of 2014. The known viral community, initially dominated by Myoviridae family (?82% of the total assigned reads), changed to become dominated by Phycodnaviridae (?90%), while viral activity was predominantly driven by dsDNA members of the Phycodnaviridae (?50%) and diatom infecting ssRNA viruses (?38%), becoming more significant as chlorophyll a increased. A genomic and phylogenetic characterization allowed the identification of a new viral lineage within the Myoviridae family. This new lineage of viruses infects Pseudoalteromonas and was dominant in the phage community. In addition, a new Phycodnavirus (PaV) was described, which is predicted to infect Phaeocystis antarctica, the main blooming haptophyte in the SO. This work was able to identify the changes in the main viral players during a bloom development and suggests that the changes observed in the virioplankton could be used as a model to understand the development and decay of blooms that occur throughout the WAP.

SUBMITTER: Alarcon-Schumacher T

PROVIDER: S-EPMC6527751 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Elucidating Viral Communities During a Phytoplankton Bloom on the West Antarctic Peninsula.

Alarcón-Schumacher Tomás T Guajardo-Leiva Sergio S Antón Josefa J Díez Beatriz B

Frontiers in microbiology 20190514

In Antarctic coastal waters where nutrient limitations are low, viruses are expected to play a major role in the regulation of bloom events. Despite this, research in viral identification and dynamics is scarce, with limited information available for the Southern Ocean (SO). This study presents an integrative-omics approach, comparing variation in the viral and microbial active communities on two contrasting sample conditions from a diatom-dominated phytoplankton bloom occurring in Chile Bay in ...[more]

PMID: 31139164

Similar Datasets

Project description:Glacio-marine fjords occur widely at high latitudes and have been extensively studied in the Arctic, where heavy meltwater inputs and sedimentation yield low benthic faunal abundance and biodiversity in inner-middle fjords. Fjord benthic ecosystems remain poorly studied in the subpolar Antarctic, including those in extensive fjords along the West Antarctic Peninsula (WAP). Here we test ecosystem predictions from Arctic fjords on three subpolar, glacio-marine fjords along the WAP. With seafloor photographic surveys we evaluate benthic megafaunal abundance, community structure, and species diversity, as well as the abundance of demersal nekton and macroalgal detritus, in soft-sediment basins of Andvord, Flandres and Barilari Bays at depths of 436-725 m. We then contrast these fjord sites with three open shelf stations of similar depths. Contrary to Arctic predictions, WAP fjord basins exhibited 3 to 38-fold greater benthic megafaunal abundance than the open shelf, and local species diversity and trophic complexity remained high from outer to inner fjord basins. Furthermore, WAP fjords contained distinct species composition, substantially contributing to beta and gamma diversity at 400-700 m depths along the WAP. The abundance of demersal nekton and macroalgal detritus was also substantially higher in WAP fjords compared to the open shelf. We conclude that WAP fjords are important hotspots of benthic abundance and biodiversity as a consequence of weak meltwater influences, low sedimentation disturbance, and high, varied food inputs. We postulate that WAP fjords differ markedly from their Arctic counterparts because they are in earlier stages of climate warming, and that rapid warming along the WAP will increase meltwater and sediment inputs, deleteriously impacting these biodiversity hotspots. Because WAP fjords also provide important habitat and foraging areas for Antarctic krill and baleen whales, there is an urgent need to develop better understanding of the structure, dynamics and climate-sensitivity of WAP subpolar fjord ecosystems.

Project description:Although crucial for the addition of new nitrogen in marine ecosystems, dinitrogen (N2) fixation remains an understudied process, especially under dark conditions and in polar coastal areas, such as the West Antarctic Peninsula (WAP). New measurements of light and dark N2 fixation rates in parallel with carbon (C) fixation rates, as well as analysis of the genetic marker nifH for diazotrophic organisms, were conducted during the late summer in the coastal waters of Chile Bay, South Shetland Islands, WAP. During six late summers (February 2013 to 2019), Chile Bay was characterized by high NO3- concentrations (~20 µM) and an NH4+ content that remained stable near 0.5 µM. The N:P ratio was approximately 14.1, thus close to that of the Redfield ratio (16:1). The presence of Cluster I and Cluster III nifH gene sequences closely related to Alpha-, Delta- and, to a lesser extent, Gammaproteobacteria, suggests that chemosynthetic and heterotrophic bacteria are primarily responsible for N2 fixation in the bay. Photosynthetic carbon assimilation ranged from 51.18 to 1471 nmol C L-1 d-1, while dark chemosynthesis ranged from 9.24 to 805 nmol C L-1 d-1. N2 fixation rates were higher under dark conditions (up to 45.40 nmol N L-1 d-1) than under light conditions (up to 7.70 nmol N L-1 d-1), possibly contributing more than 37% to new nitrogen-based production (≥2.5 g N m-2 y-1). Of all the environmental factors measured, only PO43- exhibited a significant correlation with C and N2 rates, being negatively correlated (p < 0.05) with dark chemosynthesis and N2 fixation under the light condition, revealing the importance of the N:P ratio for these processes in Chile Bay. This significant contribution of N2 fixation expands the ubiquity and biological potential of these marine chemosynthetic diazotrophs. As such, this process should be considered along with the entire N cycle when further reviewing highly productive Antarctic coastal waters and the diazotrophic potential of the global marine ecosystem.

Dataset Information

Elucidating Viral Communities During a Phytoplankton Bloom on the West Antarctic Peninsula.

Publications

Elucidating Viral Communities During a Phytoplankton Bloom on the West Antarctic Peninsula.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets