Antarctic benthic Mollusca: biodiversity, community and functional group structure in habitats influenced by varying ice-cover and the Weddell Gyre

The Southern Ocean (SO) and its Antarctic component are globally important in understanding how ecosystems and biodiversity respond to climate change. Antarctica’s unique tectonic, oceanographic and climate history have led to the SO species’ evolution and diversification happening in relative isolation, leading to the current biogeographic community structures [Refs 1, 2]. Antarctica faced and is facing changes in key environmental factors including temperature, ice-shelf and sea-ice cover, which are likely to affect/have affected marine benthic biodiversity [Ref 3]. Mollusca are one of the better-known taxa in Southern Ocean biodiversity and a suitable taxon to study the influence of environmental factors on current biodiversity, community structure and biogeographic distribution [Ref 1] and predict their future [Ref 2]. A comprehensive and comparable set of molluscan samples collected in several Antarctic areas by the same epibenthic sledge (EBS) enables application of a quantitative and multiproxy approach to assess community structure and to predict and model its future changes as well as detailed ecological and evolutionary studies at the population level.

Quantitative assessments of molluscan diversity from the shelves of the Weddell Sea and South Orkney Islands are timely as the data will be relevant for Antarctic Marine Protected Area implementation and monitoring (www.ccamlr.org).


The project will be largely lab-based, and will focus on studying existing samples of benthic Mollusca collected by EBS on continental shelves during recent cruises to the SO influenced by the Weddell gyre (JR275, JR15005, JR17003a, PS118) [Figure 1]. The project will first identify the Mollusca to the lowest possible taxonomic level, including for the classes Bivalvia and Gastropoda to species level, to examine biodiversity, community and functional trait structure. Subsequently the project will establish how those structures are influenced by environmental factors such as depth, sediment, oceanographic conditions and/or length of ice-cover. The novel geographic records from the selected classes will then be compared to known and unpublished data of biodiversity and biogeography of earlier expeditions [Figure 1, Ref 2]. From within the Bivalvia and Gastropoda, selected abundant and widely distributed morphospecies will be used for morphometric and molecular population studies on the species’ evolutionary and phylogeographic history in the area influenced by the Weddell gyre. The future distributions of these morphospecies will be modelled under future climate scenarios.

This project will give a robust assessment of how polar biodiversity and community structures will react to changing polar marine environments.

The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at the British Antarctic Survey, Cambridge. Specific training will include:

● Identification of Antarctic benthic Mollusca
● SEM and micro-CT application
● Competence with univariate and multivariate data analysis techniques
● Molecular phylogenetics from lab to analysis, e.g. DNA extraction, bioinformatics and statistical software
● ArcGIS package

The student will gain important research skills such as scientific writing and oral presentation by attending appropriate courses. Travel to international scientific meetings to present project results will also be encouraged. There will be opportunities to visit international museums for comparative collection studies. While Antarctic fieldwork is not required, if opportunities present, participation in expeditions will be considered.