Spatial and temporal environmental heterogeneity induced by internal tides influences faunal patterns on vertical walls within a submarine canyon

Pearman, Tabitha R. R., Robert, Katleen, Callaway, Alexander, Hall, Rob A. ORCID:, Mienis, Furu and Huvenne, Veerle A. I. (2023) Spatial and temporal environmental heterogeneity induced by internal tides influences faunal patterns on vertical walls within a submarine canyon. Frontiers in Marine Science, 10. ISSN 2296-7745

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Vertical walls of submarine canyons represent features of high conservation value that can provide natural areas of protection for vulnerable marine ecosystems under increasing anthropogenic pressure from deep-sea trawling. Wall assemblages are spatially heterogeneous, attributed to the high environmental heterogeneity over short spatial scales that is a typical feature of canyons. Effective management and conservation of these assemblages requires a deeper understanding of the processes that affect faunal distribution patterns. Canyons are recognised as sites of intensified hydrodynamic regimes, with focused internal tides enhancing near-bed currents, turbulent mixing and nepheloid layer production, which influence faunal distribution patterns. Faunal patterns also respond to broad-scale hydrodynamics and gradients in water mass properties (e.g. temperature, salinity, dissolved oxygen concentration). Oscillating internal tidal currents can advect such gradients, both vertically and horizontally along a canyon's walls. Here we take an interdisciplinary approach using biological, hydrodynamic and bathymetry-derived datasets to undertake a high-resolution analysis of a subset of wall assemblages within Whittard Canyon, North-East Atlantic. We investigate if, and to what extent, patterns in diversity and epibenthic assemblages on deep-sea canyon walls can be explained by spatial and temporal variability induced by internal tides. Vertical displacement of water mass properties by the internal tide was calculated from autonomous ocean glider and shipboard CTD observations. Spatial patterns in faunal assemblage structure were determined by cluster analysis and non-metric Multi-Dimensional Scaling plots. Canonical Redundancy Analysis and Generalised Linear Models were then used to explore relationships between faunal diversity and assemblage structure and a variety of environmental variables. Our results support the hypothesis that internal tides influence spatial heterogeneity in wall faunal diversity and assemblages by generating both spatial and temporal gradients in hydrodynamic properties and consequently likely food supply.

Item Type: Article
Additional Information: Funding Information: This work was based on data collected from various expeditions. JC125 was funded by the ERC CODEMAP project (Starting Grant no 258482) and the NERC MAREMAP programme, the JC035_JC036 expedition was funded by the NERC core programme OCEANS2025, the EU FP7 IP HERMIONE; the 64PE421, 64PE453 and 64PE437 expeditions were funded by the NICO initiative by NWO and NIOZ and the NWO-VIDI, grant agreement 016.161.360 and MESH Joint copyright© 2007 Defra, JNCC, Marine Institute, BGS, UoP data were recorded during a collaborative survey (MESH Cruise 01-07-01) involving the Joint Nature Conservation Committee, the Marine Institute, the British Geological Survey and the University of Plymouth. The Department of the Environment, Fisheries and Rural Affairs (Defra) Natural Environmental Group Science Division (CRO361) made a significant financial contribution to this work. The MESH work contributed to the MESH project ( that received European Regional Development Funding through the INTERREG III B Community Initiative ( TP was a PhD student in the NERC-funded SPITFIRE Doctoral Training Programme (Grant number NE/L002531/1) and received further funding from the National Oceanography Centre and the CASE partner CEFAS. VH was funded by the ERC Starting Grant project CODEMAP (Grant No 258482), by the NERC National Capability programme CLASS (Grant No NE/R015953/1), and the EU H2020 research and innovation programme project iAtlantic (grant agreement No 818123). During the final preparation stages of this manuscript she enjoyed a Fellowship from the Hanse-Wissenschaftskolleg Institute for Advanced Study. FM is supported by the innovational research scheme NWO-VIDI, grant agreement 016.161.360
Uncontrolled Keywords: cold-water coral,deep-sea,hydrodynamics,internal tides,submarine canyon,oceanography,global and planetary change,aquatic science,water science and technology,environmental science (miscellaneous),ocean engineering ,/dk/atira/pure/subjectarea/asjc/1900/1910
Faculty \ School: Faculty of Science > School of Environmental Sciences
UEA Research Groups: Faculty of Science > Research Groups > Collaborative Centre for Sustainable Use of the Seas
Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences
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Depositing User: LivePure Connector
Date Deposited: 17 Apr 2023 17:30
Last Modified: 02 May 2023 09:30
DOI: 10.3389/fmars.2023.1091855


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