Bryozoan diversity on a whale bone: an uncommon substrate from the continental shelf off NW Spain

AbstractCarcasses and bones of whales are interesting yet poorly understood habitats for invertebrates and microbial communities. Nevertheless, bryozoans have never before been reported in this particular habitat at the present day. Here, we present the first study on a bryozoan community colonizing a whale bone from the continental shelf off NW Spain at 128 m depth. Thirty-three species of bryozoans were identified, representing 50% of the known bryozoan diversity from this area and depth range. Despite this high biodiversity, no potential whale-fall specialists were detected: all the species are already known in the area, with several being more frequent in shallower or deeper waters. Our results support the hypothesis that the number of specialist taxa on whale-fall habitats decreases drastically on whale remains at depths of less than 260 m. These results also support the theory that whale-falls can serve as intermediate habitats where no other suitable substrate is present, facilitating habitat colonization.

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Active Microbial Communities Inhabit Sulphate-Methane Interphase in Deep Bedrock Fracture Fluids in Olkiluoto, Finland

BioMed Research International ◽

10.1155/2015/979530 ◽

2015 ◽

Vol 2015 ◽

pp. 1-17 ◽

Cited By ~ 43

Author(s):

Malin Bomberg ◽

Mari Nyyssönen ◽

Petteri Pitkänen ◽

Anne Lehtinen ◽

Merja Itävaara

Keyword(s):

Microbial Communities ◽

Salinity Gradient ◽

Ground Surface ◽

Gene Transcript ◽

Depth Range ◽

Transition Zones ◽

Indicator Microorganisms ◽

Crystalline Bedrock ◽

Below Ground ◽

Archaeal Communities

Active microbial communities of deep crystalline bedrock fracture water were investigated from seven different boreholes in Olkiluoto (Western Finland) using bacterial and archaeal 16S rRNA,dsrB, andmcrA gene transcript targeted 454 pyrosequencing. Over a depth range of 296–798 m below ground surface the microbial communities changed according to depth, salinity gradient, and sulphate and methane concentrations. The highest bacterial diversity was observed in the sulphate-methane mixing zone (SMMZ) at 250–350 m depth, whereas archaeal diversity was highest in the lowest boundaries of the SMMZ. Sulphide-oxidizingε-proteobacteria (Sulfurimonassp.) dominated in the SMMZ andγ-proteobacteria (Pseudomonasspp.) below the SMMZ. The active archaeal communities consisted mostly of ANME-2D and Thermoplasmatales groups, although Methermicoccaceae, Methanobacteriaceae, and Thermoplasmatales (SAGMEG, TMG) were more common at 415–559 m depth. Typical indicator microorganisms for sulphate-methane transition zones in marine sediments, such as ANME-1 archaea,α-,β- andδ-proteobacteria, JS1, Actinomycetes, Planctomycetes, Chloroflexi, and MBGB Crenarchaeota were detected at specific depths.DsrB genes were most numerous and most actively transcribed in the SMMZ while themcrA gene concentration was highest in the deep methane rich groundwater. Our results demonstrate that active and highly diverse but sparse and stratified microbial communities inhabit the Fennoscandian deep bedrock ecosystems.

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Explicit and parametrised representation of under ice shelf seas in a z<sup>*</sup> coordinate ocean model

10.5194/gmd-2017-37 ◽

2017 ◽

Cited By ~ 1

Author(s):

Pierre Mathiot ◽

Adrian Jenkins ◽

Christopher Harris ◽

Gurvan Madec

Keyword(s):

Sea Ice ◽

Continental Shelf ◽

Weddell Sea ◽

Depth Range ◽

Ice Shelf ◽

Ice Shelves ◽

Antarctic Continental Shelf ◽

Shelf Seas ◽

Ocean Properties ◽

The Antarctic

Abstract. Ice shelf/ocean interactions are a major source of fresh water on the Antarctic continental shelf and have a strong impact on ocean properties, ocean circulation and sea ice. However, climate models based on the ocean/sea ice model NEMO currently do not include these interactions in any detail. The capability of explicitly simulating the circulation beneath ice shelves is introduced in the non-linear free surface model NEMO. Its implementation into the NEMO framework and its assessment in an idealised and realistic circum-Antarctic configuration is described in this study. Compared with the current prescription of ice shelf melting (i.e. at the surface) inclusion of open sub-ice-shelf leads to a decrease sea ice thickness along the coast, a weakening of the ocean stratification on the shelf, a decrease in salinity of HSSW on the Ross and Weddell Sea shelves and an increase in the strength of the gyres that circulate within the over-deepened basins on the West Antarctic continental shelf. Mimicking the under ice shelf seas overturning circulation by introducing the meltwater over the depth range of the ice shelf base, rather than at the surface is also tested. It yields similar improvements in the simulated ocean properties and circulation over the Antarctic continental shelf than the explicit ice shelf cavity representation. With the ice shelf cavities opened, the widely-used “3 equations” ice shelf melting formulation enables an interactive computation of melting that has been assessed. Comparison with observational estimates of ice shelf melting indicates realistic results for most ice shelves. However, melting rates for Amery, Getz and George VI ice shelves are considerably overestimated.

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Polychaeta (Annelida) from the continental shelf off Aveiro (NW Portugal): Species composition and community structure

Check List ◽

10.15560/9.3.533 ◽

2013 ◽

Vol 9 (3) ◽

pp. 533 ◽

Cited By ~ 4

Author(s):

Ascensão Ravara ◽

Maria Helena Moreira

Keyword(s):

Community Structure ◽

Species Composition ◽

Continental Shelf ◽

New Records ◽

Depth Range ◽

Sediment Distribution ◽

Polychaete Species ◽

Nw Portugal ◽

Specific Composition ◽

Composition And Structure

The present study provides a checklist of the polychaete fauna collected on the continental shelf off Aveiro (NW Portugal), within an area located between latitudes 40°30’N and 40°50’N and longitudes 8°40’W and 9°20’W, and a depth range of 8 to 185 m. The list includes 136 species, belonging to 37 families, from which 19 are new records for the Portuguese coast (Isolda pulchella, Mesochaetopterus sagittarius, Aphelochaeta multibranchis, Chaetozone cf. vivipara, Diplocirrus hirsutus, Goniadella gracilis, Gyptis mediterranea, Lumbrinerides crassicephala, Eumida bahusiensis, Eumida ockelmanni, Nereiphylla paretti, Phyllodoce rosea, Glyphohesione klatti, Malmgreniella arenicolae, Prionospio aluta, Pseudopolydora paucibranchisata, Pseudopolydora pulchra, Scolelepis mesnili, Polycirrus cf. medusa). The shelf off Aveiro presents a well- defined pattern of sediment distribution, with finer sand on the inner (8–22 m depth) and the outer (94–184 m depth) parts of the shelf and coarser sediments on the mid-shelf. The distribution of polychaete assemblages follows closely the aforementioned sedimentary pattern, showing different specific composition and structure in each of the three areas. Depth was also found to play an important role in the distribution of some polychaete species.

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Data set of submerged sand deposits organised in an interoperable spatial data infrastructure (Western Sardinia, Mediterranean Sea)

Earth System Science Data ◽

10.5194/essd-11-515-2019 ◽

2019 ◽

Vol 11 (2) ◽

pp. 515-527 ◽

Cited By ~ 5

Author(s):

Walter Brambilla ◽

Alessandro Conforti ◽

Simone Simeone ◽

Paola Carrara ◽

Simone Lanucara ◽

...

Keyword(s):

Continental Shelf ◽

Mediterranean Sea ◽

Spatial Data ◽

National Research Council ◽

Western Mediterranean ◽

Spatial Data Infrastructure ◽

Depth Range ◽

Data Set ◽

Coastal System ◽

Data Infrastructure

Abstract. The expected global sea level rise by the year 2100 will determine adaptation of the whole coastal system and the land retreat of the shoreline. Future scenarios coupled with the improvement of mining technologies will favour increased exploitation of sand deposits for nourishment, especially for urban beaches and sandy coasts with lowlands behind them. The objective of the work is to provide useful tools to support planning in the management of sand deposits located on the continental shelf of Western Sardinia (western Mediterranean Sea). The work has been realised through the integration of data and information collected during several projects. Available data consist of morpho-bathymetric data (multibeam) associated with morphoacoustic (backscatter) data, collected in the depth range −25 to −700 m. Extensive coverage of high-resolution seismic profiles (Chirp 3.5 kHz) has been acquired along the continental shelf. Also, surface sediment samples (Van Veen grab and box corer) and vibrocorers have been collected. These data allow mapping of the submerged sand deposits with the determination of their thickness and volume and their sedimentological characteristics. Furthermore, it is possible to map the seabed geomorphological features of the continental shelf of Western Sardinia. All the available data (https://doi.org/10.1594/PANGAEA.895430) have been integrated and organised in a geodatabase implemented through a GIS and the software suite Geoinformation Enabling ToolkIT StarterKit® (GET-IT), developed by researchers of the Italian National Research Council for RITMARE project. GET-IT facilitates the creation of distributed nodes of an interoperable spatial data infrastructure (SDI) and enables unskilled researchers from various scientific domains to create their own Open Geospatial Consortium (OGC) standard services for distributing geospatial data, observations and metadata of sensors and data sets. Data distribution through standard services follows the guidelines of the European Directive INSPIRE (DIRECTIVE 2007/2/EC); in particular, standard metadata describe each map level, containing identifiers such as data type, origin, property, quality, processing processes to foster data searching and quality assessment.

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Nikoides schmitti Manning & Chace, 1971 (Caridea: Processidae) in the South Atlantic Ocean, with an updated list and key for processid shrimps of Brazil

Zootaxa ◽

10.11646/zootaxa.2864.1.2 ◽

2011 ◽

Vol 2864 (1) ◽

pp. 34 ◽

Cited By ~ 2

Author(s):

ALEXANDRE OLIVEIRA ALMEIDA ◽

LUIS ERNESTO ARRUDA BEZERRA

Keyword(s):

Atlantic Ocean ◽

Continental Shelf ◽

South Atlantic ◽

South Atlantic Ocean ◽

Depth Range ◽

The South ◽

Soft Bottoms ◽

First Time

The shrimp Nikoides schmitti Manning & Chace, 1971 (Decapoda: Caridea: Processidae) is reported for the first time from the South Atlantic Ocean, based on four specimens dredged on soft bottoms of the continental shelf of the Camamu Basin, Bahia, Brazil (13°28’–13°30’S; 38°47’–38°49’W), at a depth range of 38–49 m depth. The Brazilian material is illustrated and an updated list of the Brazilian processid shrimps and a key for their identification are provided.

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Uncrewed bathymetric survey in UK waters: Testing CARIS Mira AI and globally-distributed Nippon Foundation/ GEBCO training program Alumni to produce data products

10.5194/egusphere-egu21-15523 ◽

2021 ◽

Author(s):

Danai Lampridou ◽

Kemron Beache ◽

Aileen Bohan ◽

Mohamed Elsaied ◽

Travis Hamilton ◽

...

Keyword(s):

Continental Shelf ◽

Training Program ◽

Water Depth ◽

Submarine Canyon ◽

Satellite Communications ◽

Depth Range ◽

Seafloor Mapping ◽

The United Kingdom ◽

High Degree ◽

Globally Distributed

<p>SEA-KIT USV Maxlimer successfully carried out a 22 day (24hrs per day), uncrewed survey operation offshore the United Kingdom in July-August 2020. The uncrewed vessel was controlled and manoeuvred from an operation room based in Essex, UK, while the data acquisition was performed by alumni of the Nippon Foundation/GEBCO Training Program, through the Map the Gaps NPO, spread across 10 countries. One of the main objectives of the trans-ocean survey was to test the remote survey capabilities through satellite communications, and also promote the contribution to seafloor mapping. CARIS Onboard, incorporating the new Sonar Noise Classifier tool via the CARIS Mira AI platform, was deployed to autonomously process the survey data in real-time, and provide products that could be streamed daily from SEA-KIT to ensure operations were successful and to help train the classifier as required. The data was post-processed with CARIS HIPS and SIPS using conventional and Ai techniques, and gridded at 10 m. The collected data size was 52.2 GB, surveyed area depth range from 57m to 1362 with 470m mean depth and around 900 km<sup>2</sup> was totally covered.&#160; CARIS Mira AI with traditional QC approach reduced data processing time to 77% regarding the conventional path.</p><p>The high-resolution bathymetric dataset provided the first detailed picture of the Brenot Spur, adjacent to Dangeart Canyon. Three major submarine canyon systems can be identified, cross-cutting the continental shelf nearly perpendicularly. The main axis of the first canyon, located at the far northern part of the surveyed area, is oriented NE-SW and becomes wider downstream. Both of the flanks are highly carved by gullies and tributaries, especially along the northern flank, where a complex system is developed depicting well-developed amphitheatric heads, indicating retrogressive erosion. Moreover, this network shows a high degree of incision and narrow interfluves. The second major canyon trends ENE-WSW and is a multi-fed system consisting of three sub-canyons that coalesce at 1095 m water depth. Although tributaries bisect the flanks of this system, they are not mature and have not yet breached the continental shelf, but are mostly confined on the slope. The final canyon is narrower than the previous ones and its&#160; thalweg is nearly N-S oriented. Additionally, the flanks of the later differ substantially when it comes to their morphology. The western flank is undulated by linear wall gullies and several landslides indicated by the crescent like rim of high slope values, while the eastern flank is smooth and featureless. Along the SW continental slope, evidence for several old landslide events can be identified. The major failure scars are located right at the edge of the shelf at 560 m water depth.</p>

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Depth-range distribution and diversity patterns of a polychaete (Annelida) community in the continental shelf of the Southern Gulf of Mexico

Estuarine Coastal and Shelf Science ◽

10.1016/j.ecss.2021.107739 ◽

2022 ◽

pp. 107739

Author(s):

Benjamín Quiroz-Martínez ◽

Pablo Hernández-Alcántara ◽

David Alberto Salas-de León ◽

Vivianne Solís-Weiss ◽

María Adela Monreal-Gómez

Keyword(s):

Gulf Of Mexico ◽

Continental Shelf ◽

Depth Range ◽

Diversity Patterns ◽

Range Distribution ◽

Southern Gulf Of Mexico

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Recent recovery of Antarctic Bottom Water formation in the Ross Sea driven by climate anomalies

10.5194/egusphere-egu21-8371 ◽

2021 ◽

Author(s):

Alessandro Silvano ◽

Annie Foppert ◽

Steve Rintoul ◽

Paul Holland ◽

Takeshi Tamura ◽

...

Keyword(s):

Sea Ice ◽

Continental Shelf ◽

Bottom Water ◽

Ross Sea ◽

Ice Sheet ◽

Ice Formation ◽

Depth Range ◽

Antarctic Bottom Water ◽

Climate Anomalies ◽

The Antarctic

<div> <div> <div> <p>Antarctic Bottom Water (AABW) supplies the lower limb of the global overturning circulation, ventilates the abyssal ocean and sequesters heat and carbon on multidecadal to millennial timescales. AABW originates on the Antarctic continental shelf, where strong winter cooling and brine released during sea ice formation produce Dense Shelf Water, which sinks to the deep ocean. The salinity, density and volume of AABW have decreased over the last 50 years, with the most marked changes observed in the Ross Sea. These changes have been attributed to increased melting of the Antarctic Ice Sheet. Here we use in situ observations to document a recovery in the salinity, density and thickness (that is, depth range) of AABW formed in the Ross Sea, with properties in 2018&#8211;2019 similar to those observed in the 1990s. The recovery was caused by increased sea ice formation on the continental shelf. Increased sea ice formation was triggered by anomalous wind forcing associated with the unusual combination of positive Southern Annular Mode and extreme El Ni&#241;o conditions between 2015 and 2018. Our study highlights the sensitivity of AABW formation to remote forcing and shows that climate anomalies can drive episodic increases in local sea ice formation that counter the tendency for increased ice-sheet melt to reduce AABW formation.</p> </div> </div> </div>

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