scholarly journals Viruses of Polar Aquatic Environments

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 189 ◽  
Author(s):  
Sheree Yau ◽  
Mansha Seth-Pasricha
Keyword(s):  
Community Dynamics ◽  
Spatial Scales ◽  
Extreme Environments ◽  
Cold Climate ◽  
Polar Regions ◽  
Microbial Life ◽  
The North ◽  
Cellular Life ◽  
Antarctic Continent ◽  
Cycling Of Nutrients

The poles constitute 14% of the Earth’s biosphere: The aquatic Arctic surrounded by land in the north, and the frozen Antarctic continent surrounded by the Southern Ocean. In spite of an extremely cold climate in addition to varied topographies, the polar aquatic regions are teeming with microbial life. Even in sub-glacial regions, cellular life has adapted to these extreme environments where perhaps there are traces of early microbes on Earth. As grazing by macrofauna is limited in most of these polar regions, viruses are being recognized for their role as important agents of mortality, thereby influencing the biogeochemical cycling of nutrients that, in turn, impact community dynamics at seasonal and spatial scales. Here, we review the viral diversity in aquatic polar regions that has been discovered in the last decade, most of which has been revealed by advances in genomics-enabled technologies, and we reflect on the vast extent of the still-to-be explored polar microbial diversity and its “enigmatic virosphere”.

Brazilian research on extremophiles in the context of astrobiology

2012 ◽  
Vol 11 (4) ◽  
pp. 325-333 ◽  
Author(s):  
Rubens T. D. Duarte ◽  
Felipe Nóbrega ◽  
Cristina R. Nakayama ◽  
Vivian H. Pellizari
Keyword(s):  
Hydrothermal Vents ◽  
High Pressures ◽  
Human Life ◽  
Extreme Environments ◽  
Brazilian Coast ◽  
Polar Regions ◽  
Oceanic Sediments ◽  
Wide Range ◽  
Antarctic Continent ◽  
Micro Organisms

AbstractExtremophiles are organisms adapted to grow at extreme ranges of environmental variables, such as high or low temperatures, acid or alkaline medium, high salt concentration, high pressures and so forth. Most extremophiles are micro-organisms that belong to the Archaea and Bacteria domains, and are widely spread across the world, which include the polar regions, volcanoes, deserts, deep oceanic sediments, hydrothermal vents, hypersaline lakes, acid and alkaline water bodies, and other extreme environments considered hostile to human life. Despite the tropical climate, Brazil has a wide range of ecosystems which include some permanent or seasonally extreme environments. For example, the Cerrado is a biome with very low soil pH with high Al+3concentration, the mangroves in the Brazilian coast are anaerobic and saline, Pantanal has thousands of alkaline–saline lakes, the Caatinga arid and hot soils and the deep sea sediments in the Brazilian ocean shelf. These environments harbour extremophilic organisms that, coupled with the high natural biodiversity in Brazil, could be explored for different purposes. However, only a few projects in Brazil intended to study the extremophiles. In the frame of astrobiology, for example, these organisms could provide important models for defining the limits of life and hypothesize about life outside Earth. Brazilian microbiologists have, however, studied the extremophilic micro-organisms inhabiting non-Brazilian environments, such as the Antarctic continent. The experience and previous results obtained from the Brazilian Antarctic Program (PROANTAR) provide important results that are directly related to astrobiology. This article is a brief synopsis of the Brazilian experience in researching extremophiles, indicating the most important results related to astrobiology and some future perspectives in this area.

scholarly journals Time-series transcriptomics from cold, oxic subseafloor crustal fluids reveals a motile, mixotrophic microbial community

2020 ◽  
Author(s):  
L.M. Seyler ◽  
E. Trembath-Reichert ◽  
B.J. Tully ◽  
J.A. Huber
Keyword(s):  
Time Series ◽  
Microbial Community ◽  
Community Dynamics ◽  
Deep Ocean ◽  
Transcript Abundance ◽  
Global Scale ◽  
Low Oxygen ◽  
Metabolic Potential ◽  
Microbial Life ◽  
The North

AbstractThe rock-hosted oceanic crustal aquifer is one of the largest habitable volumes on Earth, and it harbors a reservoir of microbial life that influences global-scale biogeochemical cycles. Here, we use time series metagenomic and metatranscriptomic data from a low-temperature, ridge flank environment that is representative of the majority of global hydrothermal fluid circulation in the ocean to reconstruct microbial metabolic potential, transcript abundance, and community dynamics. The data suggest that the microbial community in this subseafloor habitat is motile, chiefly heterotrophic or mixotrophic, and capable of using alternative electron acceptors such as nitrate and thiosulfate, in addition to oxygen. Anaerobic processes are most abundant in subseafloor horizons deepest in the aquifer, furthest from connectivity with the deep ocean, and there was little overlap in the active microbial populations between sampling horizons. Together, our results indicate the microbial community in the North Pond aquifer plays an important role in the oxidation of organic carbon within the crust, and is also metabolically flexible, with the ability to switch from autotrophy to heterotrophy, as well as function under low oxygen conditions. This work highlights the heterogeneity of microbial life in the subseafloor aquifer and provides new insights into biogeochemical cycling in ocean crust.

scholarly journals Time-series transcriptomics from cold, oxic subseafloor crustal fluids reveals a motile, mixotrophic microbial community

2020 ◽  
Author(s):  
Lauren M. Seyler ◽  
Elizabeth Trembath-Reichert ◽  
Benjamin J. Tully ◽  
Julie A. Huber
Keyword(s):  
Time Series ◽  
Microbial Community ◽  
Community Dynamics ◽  
Deep Ocean ◽  
Transcript Abundance ◽  
Global Scale ◽  
Low Oxygen ◽  
Metabolic Potential ◽  
Microbial Life ◽  
The North

AbstractThe oceanic crustal aquifer is one of the largest habitable volumes on Earth, and it harbors a reservoir of microbial life that influences global-scale biogeochemical cycles. Here, we use time series metagenomic and metatranscriptomic data from a low-temperature, ridge flank environment representative of the majority of global hydrothermal fluid circulation in the ocean to reconstruct microbial metabolic potential, transcript abundance, and community dynamics. We also present metagenome-assembled genomes from recently collected fluids that are furthest removed from drilling disturbances. Our results suggest that the microbial community in the North Pond aquifer plays an important role in the oxidation of organic carbon within the crust. This community is motile and metabolically flexible, with the ability to use both autotrophic and organotrophic pathways, as well as function under low oxygen conditions by using alternative electron acceptors such as nitrate and thiosulfate. Anaerobic processes are most abundant in subseafloor horizons deepest in the aquifer, furthest from connectivity with the deep ocean, and there was little overlap in the active microbial populations between sampling horizons. This work highlights the heterogeneity of microbial life in the subseafloor aquifer and provides new insights into biogeochemical cycling in ocean crust.

Zooplankton Biogeochemical Cycles

2017 ◽  
Author(s):  
Deborah Steinberg
Keyword(s):  
North Atlantic ◽  
North Atlantic Ocean ◽  
Significant Proportion ◽  
Biogeochemical Cycles ◽  
Biological Pump ◽  
The North ◽  
Particle Export ◽  
Chemical Cycling ◽  
Cycling Of Nutrients ◽  
Planktonic Communities

The structure of planktonic communities profoundly affects particle export and sequestration of organic material (the biological pump) and the chemical cycling of nutrients. This chapter describes the integral and multifaceted role zooplankton (both protozoan and metazoan) play in the export and cycling of elements in the ocean, with an emphasis on the North Atlantic Ocean and adjacent seas. Zooplankton consume a significant proportion of primary production across the world's oceans, and their metabolism plays a key role in recycling carbon, nitrogen, and other elements. The chapter also addresses how human or climate-influenced changes in North Atlantic zooplankton populations may in turn drive changes in zooplankton-mediated biogeochemical cycling.

scholarly journals Study of water storage variations at the Pantanal wetlands area from GRACE monthly mass grids

2019 ◽  
Vol 9 (1) ◽  
pp. 133-143
Author(s):  
Ayelen Pereira ◽  
Cecilia Cornero ◽  
Ana C. O. C. Matos ◽  
M. Cristina Pacino ◽  
Denizar Blitzkow
Keyword(s):  
Water Mass ◽  
Spatial Scales ◽  
Water Storage ◽  
Transport Processes ◽  
Satellite Gravity ◽  
The North ◽  
Paraguay River ◽  
Gravity Recovery ◽  
Grace Mission ◽  
Phase Differences

Abstract The continental water storage is significantly in-fluenced by wetlands, which are highly affected by climate change and anthropogenic influences. The Pantanal, located in the Paraguay river basin, is one of the world’s largest and most important wetlands because of the environmental biodiversity that represents. The satellite gravity mission GRACE (Gravity Recovery And Climate Experiment) provided until 2017 time-variable Earth’s gravity field models that reflected the variations due to mass transport processes-like continental water storage changes-which allowed to study environments such as wetlands, at large spatial scales. The water storage variations for the period 2002-2016, by using monthly land water mass grids of Total Water Storage (TWS) derived from GRACE solutions, were evaluated in the Pantanal area. The capability of the GRACE mission for monitoring this particular environment is analyzed, and the comparison of the water mass changes with rainfall and hydrometric heights data at different stations distributed over the Pantanal region was carried out. Additionally, the correlation between the TWS and river gauge measurements, and the phase differences for these variables, were also evaluated. Results show two distinct zones: high correlations and low phase shifts at the north, and smaller correlation values and consequently significant phase differences towards the south. This situation is mainly related to the hydrogeological domains of the area.

scholarly journals Biogeography of acoustic biodiversity of NW Mediterranean coralligenous reefs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lucia Di Iorio ◽  
Manon Audax ◽  
Julie Deter ◽  
Florian Holon ◽  
Julie Lossent ◽  
...  
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Western Mediterranean ◽  
Ecosystem Functions ◽  
Marine Biodiversity ◽  
Predator Species ◽  
The North ◽  
Mediterranean Habitats ◽  
Geographical Regions ◽  
Nw Mediterranean

AbstractMonitoring the biodiversity of key habitats and understanding the drivers across spatial scales is essential for preserving ecosystem functions and associated services. Coralligenous reefs are threatened marine biodiversity hotspots that are challenging to monitor. As fish sounds reflect biodiversity in other habitats, we unveiled the biogeography of coralligenous reef sounds across the north-western Mediterranean using data from 27 sites covering 2000 km and 3 regions over a 3-year period. We assessed how acoustic biodiversity is related to habitat parameters and environmental status. We identified 28 putative fish sound types, which is up to four times as many as recorded in other Mediterranean habitats. 40% of these sounds are not found in other coastal habitats, thus strongly related to coralligenous reefs. Acoustic diversity differed between geographical regions. Ubiquitous sound types were identified, including sounds from top-predator species and others that were more specifically related to the presence of ecosystem engineers (red coral, gorgonians), which are key players in maintaining habitat function. The main determinants of acoustic community composition were depth and percentage coverage of coralligenous outcrops, suggesting that fish-related acoustic communities exhibit bathymetric stratification and are related to benthic reef assemblages. Multivariate analysis also revealed that acoustic communities can reflect different environmental states. This study presents the first large-scale map of acoustic fish biodiversity providing insights into the ichthyofauna that is otherwise difficult to assess because of reduced diving times. It also highlights the potential of passive acoustics in providing new aspects of the correlates of biogeographical patterns of this emblematic habitat relevant for monitoring and conservation.

scholarly journals Multicellular and unicellular responses of microbial biofilms to stress

2020 ◽  
Vol 401 (12) ◽  
pp. 1365-1374
Author(s):  
Daniel K.H. Rode ◽  
Praveen K. Singh ◽  
Knut Drescher
Keyword(s):  
Microbial Communities ◽  
Stress Responses ◽  
Spatial Scales ◽  
Organizational Level ◽  
Internal Stresses ◽  
Microbial Life ◽  
Microbial Biofilms ◽  
Applied Stresses

AbstractBiofilms are a ubiquitous mode of microbial life and display an increased tolerance to different stresses. Inside biofilms, cells may experience both externally applied stresses and internal stresses that emerge as a result of growth in spatially structured communities. In this review, we discuss the spatial scales of different stresses in the context of biofilms, and if cells in biofilms respond to these stresses as a collection of individual cells, or if there are multicellular properties associated with the response. Understanding the organizational level of stress responses in microbial communities can help to clarify multicellular functions of biofilms.

A longitudinal study of humpback whales in Irish waters

2015 ◽  
Vol 96 (4) ◽  
pp. 877-883 ◽  
Author(s):  
Conor Ryan ◽  
Pádraig Whooley ◽  
Simon D. Berrow ◽  
Colin Barnes ◽  
Nick Massett ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
North Atlantic ◽  
Spatial Scales ◽  
Humpback Whales ◽  
Migratory Species ◽  
The Public ◽  
Photo Identification ◽  
The North ◽  
Breeding Grounds ◽  
Eastern North Atlantic

Knowledge on the ecology of humpback whales in the eastern North Atlantic is lacking by comparison with most other ocean basins. Humpback whales were historically over-exploited in the region and are still found in low relative abundances. This, coupled with their large range makes them difficult to study. With the aim of informing more effective conservation measures in Ireland, the Irish Whale and Dolphin Group began recording sightings and images suitable for photo-identification of humpback whales from Irish waters in 1999. Validated records submitted by members of the public and data from dedicated surveys were analysed to form a longitudinal study of individually recognizable humpback whales. The distribution, relative abundance and seasonality of humpback whale sighting records are presented, revealing discrete important areas for humpback whales in Irish coastal waters. An annual easterly movement of humpback whales along the southern coast of Ireland is documented, mirroring that of their preferred prey: herring and sprat. Photo-identification images were compared with others collected throughout the North Atlantic (N = 8016), resulting in matches of two individuals between Ireland and Iceland, Norway and the Netherlands but no matches to known breeding grounds (Cape Verde and West Indies). This study demonstrates that combining public records with dedicated survey data is an effective approach to studying low-density, threatened migratory species over temporal and spatial scales that are relevant to conservation and management.

A reinterpretation of Scottish ‘hummocky moraine’ and its significance for the deglaciation of the Scottish Highlands during the Younger Dryas or Loch Lomond Stadial

1993 ◽  
Vol 130 (3) ◽  
pp. 301-318 ◽  
Author(s):  
Matthew R. Bennett ◽  
Geoffrey S. Boulton
Keyword(s):  
Environmental Conditions ◽  
Field Survey ◽  
Spatial Scales ◽  
Younger Dryas ◽  
North West ◽  
Scottish Highlands ◽  
Ice Cap ◽  
The North ◽  
Loch Lomond

AbstractThe aim of this paper is to demonstrate that much of the ‘hummocky moraine’ present within the northern part of the LochLomond Readvance ice cap formerly situated in the North West Scottish Highlands may be interpreted as suites of ice-front moraines deposited during active decay. These landforms can be used to reconstruct ice cap decay, whichleads to important insights into the shrinking form of the ice cap and associated environmental conditions. Evidence has been collected from 10803 airphotographs and from detailed field survey. It is presented at three spatial scales.

scholarly journals Ice processes and growth history on Arctic and sub-Arctic lakes using ERS-1 SAR data

Polar Record ◽  
1995 ◽  
Vol 31 (177) ◽  
pp. 115-128 ◽  
Author(s):  
K. Morris ◽  
M. O. Jeffries ◽  
W. F. Weeks
Keyword(s):  
Arctic Lakes ◽  
Polar Regions ◽  
Lake Ice ◽  
Sar Images ◽  
The North ◽  
Growth History ◽  
North Slope Of Alaska ◽  
Term Monitoring ◽  
Selection Of

AbstractA survey of ice growth and decay processes on a selection of shallow and deep sub-Arctic and Arctic lakes was conducted using radiometrically calibrated ERS-1 SAR images. Time series of radar backscatter data were compiled for selected sites on the lakes during the period of ice cover (September to June) for the years 1991–92 and 1992–93. A variety of lake-ice processes could be observed, and significant changes in backscatter occurred from the time of initial ice formation in autumn until the onset of the spring thaw. Backscatter also varied according to the location and depth of the lakes. The spatial and temporal changes in backscatter were most constant and predictable at the shallow lakes on the North Slope of Alaska. As a consequence, they represent the most promising sites for long-term monitoring and the detection of changes related to global warming and its effects on the polar regions.

Sign in / Sign up

Export Citation Format

Share Document