Mazzoli
Claudio
Mazzoli
Claudio
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ArticlePaleochannel and beach-bar palimpsest topography as initial substrate for coralligenous buildups offshore Venice, Italy(Nature Publishing Group, 2017-05-02) Tosi, Luigi ; Zecchin, Massimo ; Franchi, Fulvio ; Bergamasco, Andrea ; Da Lio, Cristina ; Baradello, Luca ; Mazzoli, Claudio ; Montagna, Paolo ; Taviani, Marco ; Tagliapietra, Davide ; Carol, Eleonora ; Franceschini, Gianluca ; Giovanardi, Otello ; Donnici, SandraWe provide a model for the genesis of Holocene coralligenous buildups occurring in the northwestern Adriatic Sea offshore Venice at 17–24 m depth. High-resolution geophysical surveys and underwater SCUBA diving reconnaissance revealed meandering shaped morphologies underneath bio-concretionned rocky buildups. These morphologies are inferred to have been inherited from Pleistocene fluvial systems reactivated as tidal channels during the post- Last Glacial Maximum transgression, when the study area was a lagoon protected by a sandy barrier. The lithification of the sandy fossil channel-levee systems is estimated to have occurred at ca. 7 cal. ka BP, likely due to the interaction between marine and less saline fluids related to onshore freshwater discharge at sea through a sealed water-table. The carbonate-cemented sandy layers served as nucleus for subsequent coralligenous buildups growth.
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ArticleVisual imaging of benthic carbonate-mixed factories in the Ross Sea region Marine Protected Area, Antarctica(MDPI, 2021-07-31) Castellan, Giorgio ; Angeletti, Lorenzo ; Canese, Simonepietro ; Mazzoli, Claudio ; Montagna, Paolo ; Schiaparelli, Stefano ; Taviani, MarcoMarine biogenic skeletal production is the prevalent source of Ca-carbonate in today’s Antarctic seas. Most information, however, derives from the post-mortem legacy of calcifying organisms. Prior imagery and evaluation of Antarctic habitats hosting calcifying benthic organisms are poorly present in the literature, therefore, a Remotely Operated Vehicle survey was carried out in the Ross Sea region Marine Protected Area during the 2013–2014 austral summer. Two video surveys of the seafloor were conducted along transects between 30 and 120 m (Adelie Cove) and 230 and 260 m (Terra Nova Bay “Canyon”), respectively. We quantified the relative abundance of calcifiers vs. non-calcifiers in the macro- and mega-epibenthos. Furthermore, we considered the typology of the carbonate polymorphs represented by the skeletonized organisms. The combined evidence from the two sites reveals the widespread existence of carbonate-mixed factories in the area, with an overwhelming abundance of both low-Mg and (especially) high-Mg calcite calcifiers. Echinoids, serpulids, bryozoans, pectinid bivalves and octocorals prove to be the most abundant animal producers in terms of abundance. The shallower Adelie Cove site also showed evidence of seabed coverage by coralline algae. Our results will help in refining paleoenvironmental analyses since many of the megabenthic calcifiers occur in the Quaternary record of Antarctica. We set a baseline to monitor the future response of these polar biota in a rapidly changing ocean.
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ArticleUnveiling deep-sea habitats of the Southern Ocean-facing submarine canyons of southwestern Australia(Elsevier, 2022-11-03) Trotter, Julie A. ; Taviani, Marco ; Foglini, Federica ; Sadekov, Aleksey ; Skrzypek, Grzegorz ; Mazzoli, Claudio ; Remia, Alessandro ; Santodomingo, Nadia ; Castellan, Giorgio ; McCulloch, Malcolm ; Pattiaratchi, Charitha ; Montagna, PaoloThe first expedition to the depths of the Southern Ocean facing Bremer canyon systems. First ROV images of these unique deep-sea environments and inhabitants (180 to 3300 m) Discovery of spectacular ‘animal forests’ in the Bremer and Hood canyons. Scleractinian corals found well below the aragonite saturation horizon (>1000 m) Major fossil coral deposits occur at all three study areas, especially Mount Gabi.Here we present the outcomes of the first deep-sea remotely operated vehicle study of previously unexplored submarine canyon systems along the southwest Australian continental margin. This was conducted around: (1) the Bremer Marine Park; (2) the Mount Gabi seamount and nearby slope-shelf margin at the interface of the Southern and Indian oceans; with new information from (3) the Perth Canyon Marine Park located in the SE Indian Ocean. These canyons differ from many explored around the world in having no connectivity to continental river systems, thus little detrital input, with the Bremer systems and Mount Gabi facing the Southern Ocean which plays a key role in the global ocean circulation and climate systems. Such studies in the vast deep waters around the Australian continent are rare given the lack of local ROV capability available for research, thus little is known about these environments.Using the resources of the Schmidt Ocean Institute, we characterised the submarine topography from high-resolution bathymetric mapping, geology, physical and chemical oceanography, and provide an overview of these environments including the fauna observed and collected. We show that these Southern Ocean-influenced environments incorporate South Indian Central Water, Subantarctic Mode Water, Antarctic Intermediate Water, and Upper and Lower Circumpolar Deep Water, with Antarctic Bottom Water present in deep water just south of the Bremer canyon systems. The richness in megabenthos, especially along the steep, rocky substrates of the canyon heads and walls around the Bremer canyon systems, contrasts to the comparatively depauperate fauna of the more northerly Perth Canyon. Various corals serve as important substrates for a range of other species and often exhibit particular faunal associations. Especially notable are distinct ecological zones including a bryozoan and sponge-dominated (animal) forest on the shelf edge, spectacular coral gardens along canyon margins, and the occurrence of solitary scleractinians well below the aragonite saturation horizon. Subfossil coral deposits were discovered across all three study areas, reflecting periodic waxing and waning of deep-water Scleractinia throughout this southwest region. Extensive pre-modern assemblages at Mount Gabi contrast markedly with the sparse populations of living species and suggest that it might have once been a major coral hotspot, or whether they reflect long-term coral aggregations is yet to be determined. Nevertheless, stark differences in both living and past coral distribution patterns across our study sites point to at least localised fluctuations in Southern Ocean-derived nutrient and/or oxygen supplies to these deep-sea communities.