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Mojtahid M., Fossile E., Santoni S., Husum K., Streuff K., Forwick M., Howa H., Nardelli MP. (2023). Benthic foraminifera as tools to reconstruct past tidewater glacier dynamics: A case study from Kongsfjorden (Svalbard).
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Mojtahid M., Fossile E., Santoni S., Husum K., Streuff K., Forwick M., Howa H., Nardelli MP. (2022). Benthic foraminifera as tools to reconstruct past tidewater glacier dynamics: A case study from Kongsfjorden (Svalbard).
Abstract: Located at the interface between terrestrial and marine systems, high latitude glaciated fjords are sensitive spots to current and past climate change. Kongsfjorden is located on the western part of the Svalbard archipelago and is characterized by steep environmental gradients, due to the dynamics of the tidewater glaciers, and the inflow of warm Atlantic Water (AW). Here we analyze fossil benthic foraminiferal assemblages in two main sediment cores in order to reconstruct past environmental changes in link with these environmental gradients. Sediment core 10JM-GLACIBAR-GC01, located in front of a surge-type tidewater glacier (Kronebreen complex) in the inner Kongsfjorden, represents a historical record spanning the period from 1950 to 2010 AD. In this record, we tested relationships between taxonomic and functional diversity metrics and the reconstructed distance from the glacier front. We observed a general increase in foraminiferal fluxes and diversity with the progressive glacier retreat, confirming a positive benthic response to reduced glacier-induced disturbance through time. This historical record confirms therefore the successful use of diversity metrics as proxies for tidewater glacier retreat. A study of a second sediment core, NP07-13/58-GC, spanning the last 3000 years and located in the central Kongsfjorden, was initiated to reconstruct the two end-members relationship between AW inflow and glacier retreat using benthic foraminiferal assemblages and diversity metrics applied in the historical record. The preliminary results show that until 1.6 cal ka BP and between 800 and 500 yrs cal BP, a low diversity and high relative abundances of glacier proximal species characterized the assemblages. According to the developed diversity metrics models, this suggests that the glacier grounding line/ice sheet was advanced by about 10 km compared to its position during the mid XXth century. From 1.6 to 0.8 cal ka BP and between 500 and 200 yr cal BP, taxonomic diversity increased, suggesting decreased glacial influence at the core site (in the central Kongsfjorden). Additionally, the most recent part of the record (500 – 200 yr cal BP) recorded increased relative abundance of the AW indicator Adercotryma glomeratum, suggesting increased influence of the AW carried by the West Spitsbergen Current in the central Kongsfjorden. These ecological observations need further investigations and comparison with published studies from Kongsfjorden and other Svalbard fjords. Investigations with multivariate analyses and Generalised Additive Models could help better interpret the patterns observed in term of species composition and general diversity.
Programme: 1223
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Pauline Goulet, Yan Roper-Coudert, Christophe Guinet. (2021). Using on-animal sensors to study the Ocean and its inhabitants.
Abstract: Bio-logging is a methodological approach in which miniature data recording devices are temporarily attached to free-ranging animals to monitor their movement, behaviour and physiology, as well as the physical parameters of the environment directly surrounding the animals, turning them into bio-plateformes. Unsurprisingly bio-logging emerged from marine and polar studies where the monitoring of individuals in these harsh and remote places cannot be done using traditional approaches. Miniaturization and technological advances has meant that the range of species that can be instrumented, as well as the diversity of the questions that can be sought through bio-logging, are expanding fast. New sensors are constantly being developed, pushing further the limits of this field. Instrumented animals deliver information not only on their activities but also on the physical characteristics of the environments they go through. For instance, over the last two decades, loggers attached to deep diving seals have supplemented physical oceanographic measurements with hydrographic profiles from CTD loggers but also with new series of biological measurements. For examples, fluorescence and light sensors provided information on the concentration of phytoplankton in the euphotic layer; miniature echo sounders together with high sensitivity and fast responding light sensor to detect bioluminescence, brought considerable progress in detecting small size particles (>1-2 mm) such as marine snow, zooplankton, but also fish and squids and estimate their abundance.
Keywords: Animal Distribution Bio-logger Bio-logging Drones & Cap'
Programme: 1201
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Nicolas J., Verdun J., Baltzer A., Boy JP., Lemoine JP., Perosanz F., Tafflet A., . (2023).
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. (2022). Seasonal and interannual variability of benthic foraminiferal faunas under the influence of a tidal glacier.
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Guilhermic C., Mouret A., Howa H., Pusceddu A., Baltzer A., Nardelli M.P. (2023). Effect of environmental gradients generated by tidewater glacier melting on sedimentary habitats and benthic meiofauna in Kongsfjorden (Svalbard): seasonal observations.
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. (2017).
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Baltzer A., Bourriquen M., Fournier J., Mercier D., Costa S., Tolle F., Bernard E., Jensen M. (2017). Evolution of deltas and prodeltas of the south coast of Kongsfjorden (Svalbard) from 1995 to 2022.
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Tafflet A, Nicolas J., Boy JP., Lemoine JM., Peronzans F., Durand F., Gourillon L., Baltzer A., Verdun J. (2023). Ice melting impact on crustal deformation observed by space geodesy in Svalbard.
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Portier E., Mercier D., Decaulne A. (2023).
Keywords: Deglaciation Iceland Landslides Paraglacial
Programme: 1266
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