TY - JOUR
T1 - Dynamics of Near‐Bottom Currents in Cold‐Water Coral and Sponge Areas at Valdivia Bank and Ewing Seamount, Southeast Atlantic
AU - Mohn, Christian
AU - Schwarzkopf, Franziska U.
AU - García, Patricia Jiménez
AU - Orejas, Covadonga
AU - Huvenne, Veerle A. I.
AU - Schumacher, Mia
AU - Pérez‐Rodríguez, Irene
AU - Sarralde Vizuete, Roberto
AU - López‐Abellán, Luis J.
AU - Dale, Andrew C.
AU - Devey, Colin
AU - Hansen, Jørgen L. S.
AU - Møller, Eva Friis
AU - Biastoch, Arne
N1 - © 2025. The Author(s). This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
PY - 2025/1/5
Y1 - 2025/1/5
N2 - This study investigates near-bottom currents and physical processes from simulations with the hydrodynamic model ROMS-AGRIF at two seamounts of the northeast Walvis Ridge to obtain valuable insights about drivers of observed occurrences of benthic suspension feeders (cnidarians and sponges) in this data-poor area. The spatial resolution in each model area was increased across two levels of nested grids from 1,500 m to 500 m resolution with 32 stretched terrain-following (s-) layers in the vertical with high resolution close to the bottom. The parent grids receive initial and boundary conditions from the basin-scale model INALT20 and from solutions of the OTIS inverse tidal model. The model topography is based on GEBCO data with local refinements from multi-beam data collected during different surveys in 2008, 2009, and 2010. Increasing model resolution is an important advancement for precisely evaluating the intrinsic dynamics within challenging rough terrain. We examined how near-bottom currents vary over space and time and investigated potential links between observed Cnidarian and Porifera occurrences and ranges of physical variables and processes. We identified a close link between physical processes and species distributions and suggested that physical processes such as kinetic energy dissipation and internal wave dynamics may be considered in future research as proxies of food supply to benthic suspension feeders. Such mechanistic variables may also be used to supplement more traditional descriptors such as water mass and terrain properties in species distribution models, thus enhancing our ability to predict the occurrence of benthic communities characterized by cnidarians and sponges.
AB - This study investigates near-bottom currents and physical processes from simulations with the hydrodynamic model ROMS-AGRIF at two seamounts of the northeast Walvis Ridge to obtain valuable insights about drivers of observed occurrences of benthic suspension feeders (cnidarians and sponges) in this data-poor area. The spatial resolution in each model area was increased across two levels of nested grids from 1,500 m to 500 m resolution with 32 stretched terrain-following (s-) layers in the vertical with high resolution close to the bottom. The parent grids receive initial and boundary conditions from the basin-scale model INALT20 and from solutions of the OTIS inverse tidal model. The model topography is based on GEBCO data with local refinements from multi-beam data collected during different surveys in 2008, 2009, and 2010. Increasing model resolution is an important advancement for precisely evaluating the intrinsic dynamics within challenging rough terrain. We examined how near-bottom currents vary over space and time and investigated potential links between observed Cnidarian and Porifera occurrences and ranges of physical variables and processes. We identified a close link between physical processes and species distributions and suggested that physical processes such as kinetic energy dissipation and internal wave dynamics may be considered in future research as proxies of food supply to benthic suspension feeders. Such mechanistic variables may also be used to supplement more traditional descriptors such as water mass and terrain properties in species distribution models, thus enhancing our ability to predict the occurrence of benthic communities characterized by cnidarians and sponges.
KW - cold-water corals
KW - near-bottom currents
KW - seamounts
KW - sponges
KW - tidal dynamics
KW - Walvis Ridge
KW - cold water
KW - coral reef
KW - deep sea
U2 - 10.1029/2024JC021667
DO - 10.1029/2024JC021667
M3 - Article
SN - 2169-9291
VL - 130
JO - Journal of Geophysical Research: Oceans
JF - Journal of Geophysical Research: Oceans
IS - 1
M1 - e2024JC021667
ER -