Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
44
datasets available to search
ShareScore release 0.9.0
Dataset results
44 results for “Benguela”
A 3-km model configuration of the southern Benguela Current upwelling system: ROMS model data and Pyticles Lagrangian data
<p>This dataset contains model output data from the Regional Ocean Modelling System (ROMS) configuration of the southern Benguela upwelling system (SBUS) to study the interannual variability of Lagrangian transport in the SBUS. This is a 3-km model resolution that ran for 22 years from 1989-2011 period with the first 3 years considered as spin-up. The model outputs were archived at a daily frequency. The 3-km model was nested in a 7.5 km model resolution described by Ragoasha et.al., 2019.</p> <p>The model output data provided here is a monthly climatology (1995-2011) NetCDF file of the surface temperature, salinity, the velocity fields (<em>u,v & w</em>), and sea surface height (SSH). The file that contains the model grid is also provided.</p> <p>An eddy detection and tracking algorithm were also performed on the daily 3-km SSH model outputs to study mean eddy characteristics of the region for the 1992-2011 period. The file contains identifications of the Eddies detected and tracked in out model domain, their position (longitude and latitude), vorticity, amplitude, propagation and rotational speed.</p> <p> </p> <p>An example of a Pyticles (Gula et al., 2014; Ragoasha et.al., 2019) Lagrangian output subset for 3000 Lagrangian drifters tracked for 60 days. The drifters were released in the upper 100 m depth at an across-shore transect off Cape Point (34<sup>o</sup>S). A Matlab file is also provided for monthly (1992-2011) percentage of drifters that reach St Helena Bay (32<sup>o</sup>S) from Cape Point. </p> <p> </p> <p> </p> <p><strong>Dataset provided:</strong></p> <p>Monthly climatology file: “<em>roms_avg_Y1995M1-Y2011M12.nc”</em></p> <p>Model grid file: “<em>grid_roms_avg_r3km.nc”</em></p> <p>Eddy tracking file: “<em>TRA02_SEL01_DET02_eddies_r3km_1992M1_2011M12.nc”</em></p> <p>Pyticles Lagrangian experiment output example file: “<em>Pyticles_Y2010M10.nc”</em></p> <p>Monthly transport success Matlab file: <em>"R3km_monthly_transport_1992_2011.mat"</em></p> <p> </p> <p> </p> <p><strong>Citations:</strong></p> <p> </p> <p><strong>Ragoasha, N</strong>., Herbette, S., Cambon, G., Reason, C., Roy, C., 2019. Lagrangian pathways in the southern Benguela upwelling system. <em>Journal of Marine Systems</em>, 195: 50-66.</p> <p> </p> <p>Gula, J., Molemaker, M. J., & McWilliams, J. C., 2014. Submesoscale Cold Filaments in the Gulf Stream. <em>Journal of Physical Oceanography.,</em> 44 (10), 2617–2643. DOI: 10.1175/JPO-D-14-0029.1</p> <p> </p> <p><strong>Corresponding author:</strong></p> <p>M.N. Ragoasha, ORCID identifier: 0000-0002-1500-6259. Email: moagaboragoasha@gmail.com</p> <p> </p> <p><strong>Acknowledgements:</strong></p> <p>The authors acknowledge the funding of N. Ragoasha’s PhD by the South-Africa’s National Research Foundation (NRF, South Africa) and the French Institute for Research and Sustainable Development (IRD, France). This work was also supported by the French National Program LEFE/INSU under the project’s name Benguela Upwelling Innershelf</p> <p>647 Circulation (BUIC). This work was granted access to the HPC resources of [TGCC/CINES/IDRIS] under the allocation 2017- [DARI n<sup>◦</sup>A0020107443] attributed by GENCI (Grand Equipement National de Calcul Intensif).</p>
On-shelf nutrient trapping enhances the fertility of the southern Benguela upwelling system
<p>The data submitted here is published in the manuscript entitled "On-shelf nutrient trapping enhances fertility of the southern Benguela upwelling system". Our data show that regenerated nutrients get “trapped” on the shelf of the southern Benguela upwelling system (SBUS), increasing the on-shelf nutrient pool available for upwelling. Nutrient trapping occurs when phytoplankton consume upwelled nutrients, sequestering them in their biomass, then sink and are decomposed on the shallow continental shelf, releasing nutrients to bottom waters. The nutrient-deplete surface waters subsequently flow offshore. SBUS nutrient trapping appears to be assisted by hydrographic fronts that limit the offshore transport of phytoplankton, such that their sinking and subsequent decomposition occurs on-shelf. Decomposition consumes oxygen, which means that enhanced nutrient trapping may increase oxygen depletion in the SBUS, with ecosystem-wide deleterious effects.</p> <p> </p>
FIGURE 10 in There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two
FIGURE 10. Views of Chrysaora africana: (a) in situ, (b) showing exumbrella surface and c) a graphical representation of the gastrovascular pouch shape. Wild caught ephyrae of C. africana from Walvis Bay, Namibia shown in d) stained with rose Bengal and e) unstained showing natural colours. Photographs with kind permission from (a) Simon Elwin, Namibian Dolphin Project and (b) Heidi Skrypzeck (Ministry of Fisheries and Marine Resources, Swakopmund).
FIGURE 2 in There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two
FIGURE 2. Rooted Bayesian COI tree using TPMuf+I+G model of evolution. Geographic information on collecting sites is provided in Table 1 & Appendix 1. Posterior probabilities (BY) and bootstrap support values (ML) are given above and below branches respectively. Dotted lines indicate alternative topologies present in Maximum Likelihood analyses.
FIGURE 1 in There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two
FIGURE 1. Canonical ordination plot of the discriminant functions analysis for Chrysaora fulgida, C. hysoscella, C. africana and C. agulhensis sp. nov.: δ 2 = 0.96, δ 2 = 0.94. Vector overlays show the relationship between those variables (meristic and 1 2 standardized morphometric measures) that have a Spearman Rank correlation of> 0.55 with the CAP axes. (VLW = Velar lappet width; RLW = Rhopalial lappet width; MD = Manubrium depth; ML = Manubrium length; Mouth D = Mouth diameter; OW = Ostia width; No. VL = Number of velar lappets; Max OAW = Maximum width of oral arm).
FIGURE 4 in There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two
FIGURE 4. Photographs of the Holotype specimen (MB-A088455) of Chrysaora agulhensis sp. nov. submitted to the South African Natural History Museum, collected at False Bay (Fish Hoek), South Africa in June 2014, showing a) the exumbrellar surface with characteristic star-shaped colouration and b) the subumbrellar surface showing colour and length of the oral arms, colour of manubrium as well as the shape of the velar and rhopalial lappets. The shape of the tentacular and rhopalial pouches, showing radial septum fusing at periphery of rhopalial lappets can also be seen in this image. In c) the arrangement of the primary and secondary tentacles (2:1:2) are shown, with the shape and size of the ostia also clearly visible. Enlarged images of the rhopalium which illustrates: d) the ventral view showing the hood and e) the dorsal view showing the statocyst and rhopalal canal.
FIGURE 6 in There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two
FIGURE 6. Enlarged images of the polyps of Chrysaora agulhensis sp. nov., settled from adult medusae collected at Robbin Island, South Africa in 2013: image illustrating two fully grown polyps; one strobilating (left) and one not strobilating (right).
FIGURE 8 in There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two
FIGURE 8. Microscopic images (1000 ×) of the isorhiza nematocysts occurring on the oral arms/tentacles of Chrysaora agulhensis sp. nov., C. fulgida and C. africana: a–b) undischarged A and O-isorhiza from the oral arm of C. fulgida; c) discharged holotrichous A-isorhiza from the oral arm of C. agulhensis sp. nov.; d) discharged holotrichous O-isorhiza from the oral arm of C. agulhensis sp. nov. and e) discharged atrichous anisorhiza from the oral arm of C. africana.
FIGURE 12 in There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two
FIGURE 12. Enlarged images of the ephyrae of C. fulgida: a) wild caught ephyrae stained with rose Bengal, b) wild caught ephyrae, unstained showing natural colours. Cultured ephyrae, unfed, at c) two days post liberation, d) two weeks post liberation and e) 30 days post liberation. Lappets stems, lappets, nematocyst clusters and gastric filaments clearly visible.
FIGURE 5 in There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two
FIGURE 5. Photographs of Chrysaora agulhensis sp. nov. collected at Whale Rock during November 2012 showing a) exumbrellar view of medium sized preserved specimen (12 cm) (Paratype: MB-A088456) displaying the lack of pigmentation on the central disk and shape of gonads, b) side-view of a larger specimen in situ displaying deep purple colouration of the central apex, long trailing oral arms and ribbon-like tentacles, c) enlarged image of the finger-like network of canals found toward the periphery of the rhopalial lappets and, d) subumbrella image of a large (> 20 cm) preserved specimen, showing maroon/purple colouration of the manubrium and e) uniform pigmentation found on the manubrium of larger specimens. Photograph in b) with kind permission from Peter Southwood, recreational underwater photographer.
FIGURE 7 in There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two
FIGURE 7. Enlarged images of the cultured ephyrae of C. agulhensis sp. nov., taken unfed, at a) two days post liberation, b) two weeks post liberation (indicating size of mouth) and c) two weeks post liberation (whole ephyrae). Lappets stems, lappets, nematocyst clusters and gastric filaments clearly visible.
FIGURE 11 in There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two
FIGURE 11. Photographs of live Chrysaora fulgida in the northern Benguela ecosystem, illustrating colour pattern variation between a) juvenile medusae and, b) adult medusa. Highly folded oral arms are clearly represented in b. Photographs with kind permission from Simone Neethling, The University of the Western Cape.
FIGURE 3 in There are three species of Chrysaora (Scyphozoa: Discomedusae) in the Benguela upwelling ecosystem, not two
FIGURE 3. Rooted Bayesian species tree for the concatenated nuclear dataset of 18S, ITS1, ITS2 and 5.8S based on the GTR+I+G model of evolution. Posterior probabilities (BY) and bootstrap support values (ML) are given above and below branches respectively. Dotted lines indicate alternative topologies present in Maximum Likelihood analyses. Estimated divergence times, as determined by a time calibrated (RelTime) analysis, are represented on nodes as MYA.
Drivers of short-term variability in phytoplankton production in an embayment of the southern Benguela upwelling System
<p>The data stored here are published in a manuscript entitled "Drivers of short-term variability in phytoplankton production in an embayment of the southern Benguela upwelling System" in the Journal of Marine Systems available at <a href="https://doi.org/10.1016/j.jmarsys.2020.103341">https://doi.org/10.1016/j.jmarsys.2020.103341</a>. </p> <p>The spreadsheet includes oceanographic data, namely CTD data, wind speed and direction data, oxygen concentrations, nutrient concentrations, phytoplankton nitrogen (N) and carbon (C) uptake rates, phytoplankton counts and chlorophyll concentrations.</p>
Data from: Population connectivity and phylogeography of a coastal fish, Atractoscion aequidens (Sciaenidae), across the Benguela Current region: evidence of an ancient vicariant event.
Contemporary patterns of genetic diversity and population connectivity within species can be influenced by both historical and contemporary barriers to gene flow. In the marine environment, present day oceanographic features such as currents, fronts and upwelling systems can influence dispersal of eggs/larvae and/juveniles/adults, shaping population substructuring. The Benguela Current system in the southeastern Atlantic is one of the oldest upwelling systems in the world, and provides a unique opportunity to investigate the relative influence of contemporary and historical mechanisms shaping the evolutionary history of warm-temperate fish species. Using the genetic variation in the mitochondrial DNA Control Region and eight nuclear microsatellite DNA loci, we identified the presence of two highly divergent populations in a vagile and warm-temperate fish species, Atractoscion aequidens, across the Benguela region. The geographical distributions of the two populations, on either side of the perennial upwelling cell, suggest a strong correlation between the oceanographic features of the system and the breakdown of gene flow within this species. Genetic divergence (mtDNA φST = 0.902, microsatellite FST = 0.055: probability of genetic homogeneity for either marker = p<0.001), absence of migrants (less than 1% per generation) between populations and coalescent estimates of time since most recent common ancestor suggest that the establishment of the main oceanographic features of the system (2 million years ago), particularly the strengthening and position of the perennial upwelling cell, is the most likely mechanism behind the observed isolation. Concordance between mitochondrial and nuclear genetic markers indicates that isolation and divergence of the northern and southern Benguela populations of A. aequidens occurred deep in the past and has continued to the present day. These findings suggest that the Benguela Current system may constitute an ancient and impermeable barrier to gene flow for warm-temperate fish species.
FIGURE 3 in Two new nematode species from Saldanha Bay, South Africa: Perepsilonema benguelae sp. nov. and Leptepsilonema saldanhae sp. nov. (Desmodorida, Epsilonematidae)
FIGURE 3. Leptepsilonema saldanhae sp.nov. A. Male habitus. B. Female habitus. Scale represents 50 μm.
FIGURE 2 in Two new nematode species from Saldanha Bay, South Africa: Perepsilonema benguelae sp. nov. and Leptepsilonema saldanhae sp. nov. (Desmodorida, Epsilonematidae)
FIGURE 2. Perepsilonema benguelae sp.nov. A. Male anterior body region with indication of amphidial fovea and detail of body rings in surface view. B. Female anterior body region with indication of amphidial fovea and detail of body rings in surface view. C. Male posterior body region with reproductive system. D. Female posterior body region with reproductive system. Scale represents 20 μm.
FIGURE 4 in Two new nematode species from Saldanha Bay, South Africa: Perepsilonema benguelae sp. nov. and Leptepsilonema saldanhae sp. nov. (Desmodorida, Epsilonematidae)
FIGURE 4. Leptepsilonema saldanhae sp.nov. A. Male anterior body region with indication of amphidial fovea and detail of body rings in surface view. B. Female anterior body region with indication of amphidial fovea and detail of body rings in surface view. C. Male posterior body region with reproductive system. D. Female posterior body region with reproductive system. Scale represents 20 μm.
FIGURE 1 in Two new nematode species from Saldanha Bay, South Africa: Perepsilonema benguelae sp. nov. and Leptepsilonema saldanhae sp. nov. (Desmodorida, Epsilonematidae)
FIGURE 1. Perepsilonema benguelae sp.nov. A. Male habitus. B. Female habitus. Scale represents 50 μm.
FIGURE 7 in A new species of habitat – forming Suberites (Porifera, Demospongiae, Suberitida) in the Benguela upwelling region (South Africa)
FIGURE 7. Geographical distribution of Suberites dandelenae sp. nov. along the west coast of South Africa (Green dots); Red dots—other sponge species distributions collected during trawl surveys.
ScienceDex guides
Understand access before you commit
These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.