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Université de Fribourg

The genus Amphistegina (benthic foraminifera): distribution along the southern Tunisian coast

Kateb, Akram El ; Stalder, Claudio ; Stainbank, Stephanie ; Fentimen, Robin ; Spezzaferri, Silvia

In: BioInvasions Records, 2018, vol. 7, no. 4, p. 391–398

The benthic foraminiferal genus Amphistegina is currently expanding its range in the Mediterranean Sea after being introduced through the Suez Canal from the Red Sea. Over the previous decade, Amphistegina spp. has colonized the eastern part of the Mediterranean Sea including the Egyptian and Libyan coasts, but the present southern limit in the Mediterranean Sea is along the southern Tunisian...

Université de Fribourg

New insights on coral mound development from groundtruthed high-resolution ROV-mounted multibeam imaging

Lim, Aaron ; Huvenne, Veerle A.I. ; Vertino, Agostina ; Spezzaferri, Silvia ; Wheeler, Andrew J.

In: Marine Geology, 2018, vol. 403, p. 225–237

Currents play a vital role in sustaining and developing deep water benthic habitats by mobilising food and nutrients to otherwise relatively barren parts of the seabed. Where sediment supply is significant, it can have a major influence on the development and morphology of these habitats. This study examines a segment of the Belgica Mound Province, NE Atlantic to better constrain the...

Université de Fribourg

High-resolution monitoring of water temperature and oxygen concentration in Lake Murten (Switzerland)

Kateb, Akram El ; Rüggeberg, Andres ; Stalder, Claudio ; Neururer, Christoph ; Spezzaferri, Silvia

In: Swiss Journal of Geosciences, 2018, vol. 111, no. 3, p. 501–510

Lake Murten is located in the Lake District in western Switzerland and so far, it has been poorly investigated. The Environmental Service of Fribourg (SEn) has monitored this lake once a month for several years by water profiles (water temperature, pH, dissolved oxygen, conductivity) at its deepest part. The SEn identified the stratification of water masses as one of the main causes for...

Université de Fribourg

Benthic foraminifera in a deep-sea high-energy environment: the Moira Mounds (Porcupine Seabight, SW of Ireland)

Fentimen, Robin ; Rüggeberg, Andres ; Lim, Aaron ; El Kateb, Akram ; Foubert, Anneleen ; Wheeler, Andrew J. ; Spezzaferri, Silvia

In: Swiss Journal of Geosciences, 2018, vol. 111, no. 3, p. 561–572

Cold-water coral ecosystems represent unique and exceptionally diverse environments in the deep-sea. They are well developed along the Irish margin, varying broadly in shape and size. The Moira Mounds, numerous small-sized mounds, are nestled in the Belgica Mound Province (Porcupine Seabight, North-East Atlantic). The investigation of living (Rose Bengal stained) and dead benthic...

Université de Fribourg

Origin and age of carbonate clasts from the Lusi eruption, Java, Indonesia

Samankassou, Elias ; Mazzini, Adriano ; Chiaradia, Massimo ; Spezzaferri, Silvia ; Moscariello, Andrea ; Couto, Damien Do

In: Marine and Petroleum Geology, 2018, vol. 90, p. 138–148

Deep stratigraphic constrains below the Indonesian Lusi mud eruption are currently lacking due to the absence of deep wells and good quality seismic data. A collection of carbonate clasts has been sampled from the Lusi site, active since its birth in 2006. These specimens are part of a large variety of lithotypes erupted from the main crater. The carbonates analysed comprise scleractinian...

Université de Fribourg

Impact of industrial phosphate waste discharge on the marine environment in the Gulf of Gabes (Tunisia)

Kateb, Akram El ; Stalder, Claudio ; Rüggeberg, Andres ; Neururer, Christoph ; Spangenberg, Jorge E. ; Spezzaferri, Silvia

In: PLOS ONE, 2018, vol. 13, no. 5, p. e0197731

The marine environment in the Gulf of Gabes (southern Tunisia) is severely impacted by phosphate industries. Nowadays, three localities, Sfax, Skhira and Gabes produce phosphoric acid along the coasts of this Gulf and generate a large amount of phosphogypsum as a waste product. The Gabes phosphate industry is the major cause of pollution in the Gulf because most of the waste is directly...

Université de Fribourg

In situ observations of foraminiferal bleaching in the maldives, indian ocean

Spezzaferri, Silvia ; El Kateb, Akram ; Pisapia, Chiara ; Hallock, Pamela

In: Journal of Foraminiferal Research, 2018, vol. 48, no. 1, p. 75–84

Coral reefs are threatened worldwide by a variety of natural and human-induced stressors; anomalous temperatures are presently among the most serious threats by causing extensive coral bleaching. Amphistegina spp. exhibit similar bleaching as corals in the presence of photo-oxidative stress induced by either light or temperature, especially during times of maximum solar irradiance. At 11...

Université de Fribourg

Late Weichselian deglaciation and early Holocene development of a cold-water coral reef along the Lopphavet shelf (Northern Norway) recorded by benthic foraminifera and ostracoda

Stalder, Claudio ; Spezzaferri, Silvia ; Rüggeberg, Andres ; Pirkenseer, Claudius ; Gennari, Giordana

In: Deep Sea Research Part II: Topical Studies in Oceanography, 2014, vol. 99, p. 249–269

Cold-water coral (CWC) settlement in northern Norway is strongly related to the outlet-glaciers of the Fennoscandian Ice-sheet, and dating of known CWC structures show clearly post-glacial ages. Two gravity cores (POS391 559/2,277 cm long and POS391 559/3,282 cm long) were recovered on a CWC reef in the area of Lopphavet, northern Norway. Detailed investigations on lithology (sediment structures...

Université de Fribourg

The Helgoland Experiment – assessing the influence of methodologies on Recent benthic foraminiferal assemblage composition

Schönfeld, Joachim ; Golikova, Elena ; Korsun, Sergei ; Spezzaferri, Silvia

In: Journal of Micropalaeontology, 2013, vol. 32, no. 2, p. 161–182

The aim of the present study was to compare preservation, staining and preparation techniques to assess the influence of different sample treatments and analyses on the accuracy of benthic foraminiferal assemblage data from NE Atlantic shelf seas. Replicate surface samples from the SE North Sea were preserved with ethanol–rose Bengal or formalin, some were stained after processing, or...

Université de Fribourg

Benthic foraminifer assemblages from norwegian cold-Water coral reefs

Spezzaferri, Silvia ; Rüggeberg, Andres ; Stalder, Claudio ; Margreth, Stephan

In: Journal of Foraminiferal Research, 2013, vol. 43, no. 1, p. 21-39

Quantitative investigations on the total (living + dead) benthic foraminiferal assemblages were performed on 32 surface-sediment samples (0–2 cm, .63-mm size fraction) from water depths ranging from 110–600 m (‘‘on-reef’’) to .2000 m (‘‘off-reef’’) in the Oslo Fjord (Skagerrak Basin), the mid-Norwegian slope (Sula, Røst, and Trænadjupet reefs), and the northern coral-reef...