Programme website: http://inspire-dtp.ac.uk
The objective is to study the taxonomy, biodiversity, phylogeography and population genetic patterns of under-ice shelf fauna with a focus on polychaetes. This will help provide independent evidence for ice shelf retreats and expansions as reflected by the evolutionary and demographic history of fauna that depend on ice shelf cover.
The Antarctic ice sheet drains towards and terminates in the ocean, where it forms floating glaciers, or ice shelves, overlying vast sub-ice cavities. The largest of the ice shelves are the size of France, and they are unexplored oceans underlying sheets of ice that are 300-100 m thick. There are only a handful of published investigations of under-ice shelf fauna (Lipps et al., 1979; Post et al., 2007; Sugiyama et al., 2014), none with genetic data. The phylogenetic origin of the under-ice shelf fauna is as of yet unknown. Did it evolve from nearby Antarctic shelf species or did elements of this fauna colonize from the surrounding deep sea, already adapted to an energy-poor environment? (Neal et al 2017). The evolutionary origin and age, as well as demographical changes to this fauna, can be assessed through phylogenetic and population genetic analyses (Brasier et al., 2016; Brasier et al., 2017). Together, these new genetic data can provide an independent, biological, line of evidence regarding the timing of ice-sheet advance and retreat.
The new collections from the LarsenCBenthos expedition will be studied using morphological and molecular taxonomy of polychaetes coupled with eDNA metabarcoding of filtered bottom water. Additional eDNA samples will be made available from the Thwaites glacier project via samples taken with the new University of Gothenburg AUV. This will be the first time these types of samples have been analysed for ice shelf fauna.
Specifically, detailed taxonomic studies and library creation of polychaetes will involve electron microscopy, photomicroscopy, molecular barcoding, sequence alignment, phylogenetic analysis using Bayesian inference and genetic distance estimation to differentiate species. This new library of barcoded polychaetes will be combined with the extensive data already created by NHM/BAS group from the BIOPEARL 1 and 2 expeditions (Neal et al., 2017; Brasier et al., 2016, 2017). This will create an unparalleled opportunity to undertake metabarcoding approaches with a comparative library rather than just creating a list of unknown taxonomic units.
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 NHM with visits to all partners. Specific training will include:
At-sea specimen collecting and imagery including eDNA, light and scanning electron microscopy, dissection, high-resolution specimen photography, data management (DarwinCore, OBIS, WoRMS), molecular barcoding techniques, phylogenetic analysis, population genetic analysis, metabarcoding analysis, next-generation sequencing and bioinformatics. It is likely the student will be able to participate in further Antarctic or other deep-sea cruises through collaboration
Neal L, Linse K, Brasier MJ, Sherlock E, Glover AG. Comparative marine biodiversity and depth zonation in the Southern Ocean: evidence from a new large polychaete dataset from Scotia and Amundsen seas. Marine Biodiversity. 2018 Mar 1;48(1):581-601.
Brasier MJ, Wiklund H, Neal L, Jeffreys R, Linse K, Ruhl H, Glover AG. DNA barcoding uncovers cryptic diversity in 50% of deep-sea Antarctic polychaetes. Royal Society open science. 2016 Nov 1;3(11):160432.
Brasier, Madeleine J., et al. "Distributional Patterns of Polychaetes Across the West Antarctic Based on DNA Barcoding and Particle Tracking Analyses." Frontiers in Marine Science 4 (2017): 356.