Investigating the Prevailing Hydrodynamics Around a Cold-Water Coral Colony Using a Physical and a Numerical Approach

Framework-forming cold-water corals provide a refuge for numerous organisms and, consequently, the ecosystems formed by these corals can be considered as impressive deep-sea biodiversity hotspots. If suitable environmental conditions for coral growth persist over sufficiently long periods of time in equilibrium with continuous sediment input, substantial accumulations of coral mound deposits consisting of coral fragments and baffled sediments can form. Although this conceptual approach is widely accepted, little is known about the prevailing hydrodynamics in their close proximity, which potentially affect sedimentation patterns. In order to refine the current understanding about the hydrodynamic mechanisms in the direct vicinity of a model cold-water coral colony, a twofold approach of a laboratory flume experiment and a numerical model was set up. In both approaches the flow dynamics around a simplified cold-water coral colony used as current obstacle were investigated. The flow measurements of the flume provided a dataset that served as the basis for validation of the numerical model. The numerical model revealed data from the vicinity of the simplified cold-water coral, such as the pressure field, velocity field, or the turbulent kinetic energy (TKE) in high resolution. Features of the flow like the turbulent wake and streamlines were also processed to provide a more complete picture of the flow that passes the simplified cold-water coral colony. The results show that a cold-water coral colony strongly affects the flow field and eventually the sediment dynamics. The observed decrease in flow velocities around the cold water-coral hints to a decrease in the sediment carrying potential of the flowing water with consequences for sediment deposition.

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Bathymetrical distribution and size structure of cold-water coral populations in the Cap de Creus and Lacaze-Duthiers canyons (northwestern Mediterranean)

Biogeosciences ◽

10.5194/bg-10-2049-2013 ◽

2013 ◽

Vol 10 (3) ◽

pp. 2049-2060 ◽

Cited By ~ 87

Author(s):

A. Gori ◽

C. Orejas ◽

T. Madurell ◽

L. Bramanti ◽

M. Martins ◽

...

Keyword(s):

Mediterranean Sea ◽

Cold Water ◽

Size Structure ◽

First Record ◽

Lophelia Pertusa ◽

Submarine Canyons ◽

Remotely Operated Vehicle ◽

Coral Colony ◽

The Mediterranean ◽

Water Coral

Abstract. Submarine canyons are known as one of the seafloor morphological features where living cold-water coral (CWC) communities develop in the Mediterranean Sea. We investigated the CWC community of the two westernmost submarine canyons of the Gulf of Lions canyon system: the Cap de Creus Canyon (CCC) and Lacaze-Duthiers Canyon (LDC). Coral associations have been studied through video material recorded by means of a manned submersible and a remotely operated vehicle. Video transects have been conducted and analyzed in order to obtain information on (1) coral bathymetric distribution and density patterns, (2) size structure of coral populations, and (3) coral colony position with respect to the substrate. Madrepora oculata was the most abundant CWC in both canyons, while Lophelia pertusa and Dendrophyllia cornigera mostly occurred as isolated colonies or in small patches. An important exception was detected in a vertical cliff in LDC where a large L. pertusa framework was documented. This is the first record of such an extended L. pertusa framework in the Mediterranean Sea. In both canyons coral populations were dominated by medium and large colonies, but the frequent presence of small-sized colonies also indicate active recruitment. The predominant coral orientation (90° and 135°) is probably driven by the current regime as well as by the sediment load transported by the current flows. In general, no clear differences were observed in the abundance and in the size structure of the CWC populations between CCC and LDC, despite large differences in particulate matter between canyons.

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Bathymetrical distribution and size structure of cold-water coral populations in the Cap de Creus and Lacaze-Duthiers canyons (northwestern Mediterranean)

Biogeosciences Discussions ◽

10.5194/bgd-9-19053-2012 ◽

2012 ◽

Vol 9 (12) ◽

pp. 19053-19084 ◽

Cited By ~ 2

Author(s):

A. Gori ◽

C. Orejas ◽

T. Madurell ◽

L. Bramanti ◽

M. Martins ◽

...

Keyword(s):

Mediterranean Sea ◽

Cold Water ◽

Size Structure ◽

First Record ◽

Lophelia Pertusa ◽

Submarine Canyons ◽

Remotely Operated Vehicle ◽

Coral Colony ◽

The Mediterranean ◽

Water Coral

Abstract. Submarine canyons are known as one of the seafloor morphological features where living cold-water coral (CWC) communities develop in the Mediterranean Sea. We investigated the CWC community of the two westernmost submarine canyons of the Gulf of Lions canyon system: the Cap de Creus Canyon (CCC) and Lacaze Duthiers Canyon (LDC). Coral associations have been studied through video material recorded by means of a manned submersible and a remotely operated vehicle. Video transects have been conducted and analyzed in order to obtain information on (1) coral bathymetric distribution and density patterns, (2) size structure of coral populations, and (3) coral colony orientation with respect to the substrate. Madrepora oculata was the most abundant CWC in both canyons, while Lophelia pertusa and Dendrophyllia cornigera mostly occurred as isolated colonies or in small patches. An important exception was detected in a vertical cliff in LDC where a large Lophelia pertusa framework was documented. This is the first record of such an extended L. pertusa framework in the Mediterranean Sea. In both canyons coral populations were dominated by medium and large colonies, but the frequent presence of small-sized colonies also indicate active recruitment. The predominant coral orientation with respect to the substrate (90° and 135°) is probably driven by the current regime as well as by the sediment load transported by the current flows. In general no clear differences were observed between the CWC populations from CCC and LDC, despite large differences in particulate matter between canyons.

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Late Weichselian deglaciation and early Holocene development of a cold-water coral reef along the Lopphavet shelf (Northern Norway) recorded by benthic foraminifera and ostracoda

Deep Sea Research Part II Topical Studies in Oceanography ◽

10.1016/j.dsr2.2013.07.009 ◽

2014 ◽

Vol 99 ◽

pp. 249-269 ◽

Cited By ~ 15

Author(s):

Claudio Stalder ◽

Silvia Spezzaferri ◽

Andres Rüggeberg ◽

Claudius Pirkenseer ◽

Giordana Gennari

Keyword(s):

Coral Reef ◽

Benthic Foraminifera ◽

Cold Water ◽

Early Holocene ◽

Northern Norway ◽

Late Weichselian ◽

Water Coral

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Numerical Aspects of Particle-in-Cell Simulations for Plasma-Motion Modeling of Electric Thrusters

Aerospace ◽

10.3390/aerospace8050138 ◽

2021 ◽

Vol 8 (5) ◽

pp. 138

Author(s):

Giuseppe Gallo ◽

Adriano Isoldi ◽

Dario Del Gatto ◽

Raffaele Savino ◽

Amedeo Capozzoli ◽

...

Keyword(s):

Numerical Model ◽

Computing Time ◽

Computational Time ◽

Electric Motors ◽

Motion Modeling ◽

Particle In Cell ◽

Computing Platform ◽

Hall Effect Thruster ◽

Set Up ◽

Pic Code

The present work is focused on a detailed description of an in-house, particle-in-cell code developed by the authors, whose main aim is to perform highly accurate plasma simulations on an off-the-shelf computing platform in a relatively short computational time, despite the large number of macro-particles employed in the computation. A smart strategy to set up the code is proposed, and in particular, the parallel calculation in GPU is explored as a possible solution for the reduction in computing time. An application on a Hall-effect thruster is shown to validate the PIC numerical model and to highlight the strengths of introducing highly accurate schemes for the electric field interpolation and the macroparticle trajectory integration in the time. A further application on a helicon double-layer thruster is presented, in which the particle-in-cell (PIC) code is used as a fast tool to analyze the performance of these specific electric motors.

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Predicting suitable habitat for the cold-water coral Lophelia pertusa (Scleractinia)

Deep Sea Research Part I Oceanographic Research Papers ◽

10.1016/j.dsr.2008.04.010 ◽

2008 ◽

Vol 55 (8) ◽

pp. 1048-1062 ◽

Cited By ~ 185

Author(s):

Andrew J. Davies ◽

Max Wisshak ◽

James C. Orr ◽

J. Murray Roberts

Keyword(s):

Cold Water ◽

Suitable Habitat ◽

Lophelia Pertusa ◽

Water Coral

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Living benthic foraminifera from cold-water coral ecosystems in the eastern Alboran Sea, Western Mediterranean

Heliyon ◽

10.1016/j.heliyon.2021.e07880 ◽

2021 ◽

pp. e07880

Author(s):

Claudio Stalder ◽

Akram El Kateb ◽

Jorge E. Spangenberg ◽

Loubna Terhzaz ◽

Agostina Vertino ◽

...

Keyword(s):

Benthic Foraminifera ◽

Cold Water ◽

Western Mediterranean ◽

Alboran Sea ◽

Alborán Sea ◽

Water Coral

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Seabed mapping for selecting cold-water coral protection areas on Hatton Bank, Northeast Atlantic

ICES Journal of Marine Science ◽

10.1093/icesjms/fsp170 ◽

2009 ◽

Vol 66 (9) ◽

pp. 2013-2025 ◽

Cited By ~ 20

Author(s):

P. Durán Muñoz ◽

M. Sayago-Gil ◽

J. Cristobo ◽

S. Parra ◽

A. Serrano ◽

...

Keyword(s):

Deep Sea ◽

Ad Hoc ◽

Cold Water ◽

Interdisciplinary Approach ◽

Western Slope ◽

Northeast Atlantic ◽

Fisheries Science ◽

Seabed Mapping ◽

Del Rio ◽

Water Coral

Abstract Durán Muñoz, P., Sayago-Gil, M., Cristobo, J., Parra, S., Serrano, A., Díaz del Rio, V., Patrocinio, T., Sacau, M., Murillo, F. J., Palomino, D., and Fernández-Salas, L. M. 2009. Seabed mapping for selecting cold-water coral protection areas on Hatton Bank, Northeast Atlantic. – ICES Journal of Marine Science, 66: 2013–2025. Research into vulnerable marine ecosystems (VMEs) on the high seas and the impacts of bottom fishing and ad hoc management measures are high priority today thanks to UN General Assembly Resolution 61/105. An interdisciplinary methodology (specifically designed for selecting cold-water coral protection areas) and a case study focused on the Hatton Bank (NE Atlantic) are presented. This interdisciplinary approach, developed under the ECOVUL/ARPA project, was based on conventional fisheries science, geomorphology, benthic ecology, and sedimentology. It contributes to defining practical criteria for identifying VMEs, to improving knowledge of their distribution off Europe's continental shelf, and to providing advice on negative fishing impacts and habitat protection. The approach was used to identify the bottom-trawl deep-sea fishery footprint on the western slope of Hatton Bank, to map the main fishing grounds and related deep-sea habitats (1000–1500 m deep), and to study the interactions between fisheries and cold-water corals. The results lead to a proposal to close the outcrop area (4645 km2) located on the western slope of Hatton Bank as a conservation measure for cold-water corals.

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