The area west of the Kerguelen Islands (20-70°E/45-60°S) is characterized by a weak mesoscale activity except for a standing meander region of the Antarctic Circumpolar Current (ACC) localized between 20 and 40°E. A unique bio-physical dataset at high-resolution collected by a southern elephant seal (Mirounga leonina) reveals a conspicuous increase in foraging activity at the standing meander site up to 5 times larger than during the rest of her three-month trip west of the Kerguelen Islands. Here, we propose a physical explanation for such high biological activity based on the study of small-scale fronts with scales of 5 to 20 km, also called submesoscales. The standing meander is associated with intensified frontal dynamics at submesoscale, not observed in the rest of the region. Results shed new light on the spatial distribution of submesoscale fronts in the under-sampled area west of the Kerguelen plateau and emphasize their importance for upper trophic levels. Despite that most elephant seals target foraging grounds east of the Kerguelen Plateau, our findings suggest that excursions to the west are not accidental, and may be explained by the recurrently elevated physical and biological activity of the site. As such, other standing meanders of the ACC may also act as biological hotspots where trophic interactions are stimulated by submesoscale turbulence.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6447572 | PMC |
http://dx.doi.org/10.1038/s41598-019-42117-w | DOI Listing |
Sci Rep
May 2021
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Alten Hafen 26, 27568, Bremerhaven, Germany.
Plate kinematic models propose that India and Sri Lanka (INDSRI) separated from Antarctica by extremely slow seafloor spreading that started in early Cretaceous times, and that a long-distance ridge jump left a continental fragment stranded off the Antarctic margin under the Southern Kerguelen Plateau . Here, we present newly acquired magnetic and deep wide-angle seismic data that require a fundamental re-evaluation of these concepts. The new data clearly define the onset of oceanic crust in the Enderby Basin and off southern Sri Lanka, and date its formation with unprecedented confidence.
View Article and Find Full Text PDFSci Rep
December 2019
Institute for Marine and Antarctic Studies, IMAS Waterfront Building, 20 Castray Esplanade, Battery Point, Tasmania, 7004, Australia.
Mesopelagic fish and squid occupy ocean depths extending below the photic zone and their vertical migrations represent a massive pathway moving energy and carbon through the water column. Their spatio-temporal distribution is however, difficult to map across remote regions particularly the vast Southern Ocean. This represents a key gap in understanding biogeochemical processes, marine ecosystem structure, and how changing ocean conditions will affect marine predators, which depend upon mesopelagic prey.
View Article and Find Full Text PDFZootaxa
June 2019
South China Sea Environmental Monitoring Center, State Oceanic Administration, 155 Xingangxi Road, Guangzhou, P. R. China Australian Museum Research Institute, Australian Museum, 1, William Street, 2010, New South Wales, Australia Department of Biological Sciences, Macquarie University, North Ryde 2109, Australia.
Petta Malmgren, 1866 is a small and poorly known genus of the annelid family Pectinariidae Quatrefages, 1866. Prior to this study, the genus comprised four species P. pusilla Malmgren, 1866 (type locality Gullmarsfjord, west coast of Sweden), P.
View Article and Find Full Text PDFFront Zool
August 2019
1Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy 55, 81-712 Sopot, Poland.
Background: Large numbers of endemic species inhabit subantarctic continental coasts and islands that are characterised by highly variable environmental conditions. Southern hemisphere populations of taxa that are morphologically similar to northern counterparts have traditionally been considered to be extensions of such Northern hemisphere taxa, and may not exhibit differentiation amongst geographically isolated populations in the Southern Ocean. Smooth-shelled blue mussels of the genus that exhibit an anti-tropical distribution are a model group to study phylogeography, speciation and hybridisation in the sea, and contribute to the theory and practice of marine biosecurity.
View Article and Find Full Text PDFThe area west of the Kerguelen Islands (20-70°E/45-60°S) is characterized by a weak mesoscale activity except for a standing meander region of the Antarctic Circumpolar Current (ACC) localized between 20 and 40°E. A unique bio-physical dataset at high-resolution collected by a southern elephant seal (Mirounga leonina) reveals a conspicuous increase in foraging activity at the standing meander site up to 5 times larger than during the rest of her three-month trip west of the Kerguelen Islands. Here, we propose a physical explanation for such high biological activity based on the study of small-scale fronts with scales of 5 to 20 km, also called submesoscales.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!
© LitMetric 2025. All rights reserved.