Living and dead benthic foraminiferal distribution in two areas of the Ross Sea (Antarctica)
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Living and dead benthic foraminiferal distribution in two areas of the Ross Sea (Antarctica) Lucilla Capotondi1 · Sergio Bonomo2,3 · Giorgio Budillon4 · Patrizia Giordano5 · Leonardo Langone5 Received: 19 March 2020 / Accepted: 6 August 2020 © Accademia Nazionale dei Lincei 2020
Abstract We investigated the living (stained) and dead benthic foraminiferal assemblages collected in surface sediment samples (0–1 cm) from two different areas (JOIDES Basin and Mawson Bank) of the Ross Sea (Antarctica). Samples were collected during the BEDROSE oceanographic cruise from January to February 2017. Four living and dead benthic foraminiferal fauna assemblages have been distinguished based on cluster analysis. The differences observed in the living and dead foraminiferal content from the two investigated areas are the result of taphonomic processes induced by the different oceanographic settings and environmental conditions. In the JOIDES Basin, agglutinated taxa Rhabdamminella cylindrica, Lagenammina difflugiformis, Adercotryma glomeratum, Recurvoides contortus, Reophax subfusiformis with high percentages of Trochammina group and Reophax spiculifer associated with the calcareous species Nonionella bradii and Astrononion echolsi characterize the living assemblages. The comparison between living and dead benthic foraminifera reveals considerable similarities in terms of the presence/absence of agglutinated species and differences in relative abundance of calcareous taxa. However, the major influencing factor in foraminiferal preservation appears to be the carbonate dissolution. Results from Mawson Bank show an almost exclusive presence of calcareous taxa with high percentages of Globocassidulina group in both living and dead assemblages. The dead fauna assemblage differs from the corresponding living assemblage by being more diverse documenting high-energy current influence on marine sedimentation.
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s12210-020-00949-z) contains supplementary material, which is available to authorized users. Extended author information available on the last page of the article
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Rendiconti Lincei. Scienze Fisiche e Naturali
Graphic abstract
Keywords Benthic foraminifera · Living and dead assemblages · Environmental conditions · Antarctica · Ross Sea
1 Introduction Benthic foraminifera are protozoa with calcareous, siliceous, agglutinated or organic-walled tests highly sensitive to marine environmental conditions (Murray 2014). These characteristics, in combination with their fossil potential, make this group an excellent proxy to decipher past environmental and oceanographic changes (Jorissen et al. 2007 and references therein). However, this requires a good knowledge of the ecology of recent species as well as of the processes related to the transition from a living community into a dead one and then fossil assemblage. In this context, the identification of differences detected between living and dead faunas detected
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