Project Title

Collaborative Research: Have trans-antarctic dispersal corridors impacted Antarctic marine biodiversity?

Summary

Event Number:
B-305-N
NSF/OPP Award 1916661

Program Manager:
Dr. Karla Heidelberg

ASC POC/Implementer:
David Rivera / Jamee Johnson

Principal Investigator(s)

Dr. Kenneth Halanych
ken@auburn.edu
Auburn University
Auburn, Alabama

Location

Supporting Stations: RV/IB Nathaniel B. Palmer
Research Locations: Weddell Sea

Description

The overarching goal of this research is to understand environmental factors that have shaped patterns of present-day diversity in Antarctic benthic marine invertebrates. Evidence from sediment cores and modeling suggests ice shelf collapses have occurred multiple times in the last few million years. During these periods, transantarctic seaways connected the Ross and Weddell Seas. This research will assess whether the presence of transantarctic waterways helps explain observed similarities between the Ross and Weddell Seas benthic marine invertebrate fauna better than other current hypotheses (e.g., dispersal by the Antarctic Circumpolar Current, or expansion from common glacial refugia). Seven Antarctic benthic invertebrate taxa will be targeted to test alternative hypothesis about the origins of population genetic structure in the Southern Ocean using Single Nucleotide Polymorphism (SNP) markers that sample thousands of loci across the genome. Additionally, research will test the current paradigm that divergence between closely related, often cryptic, species is the result of population bottlenecks caused by glaciation. Specifically, SNP data will be mapped on to draft genomes of three of our target taxa to assess the degree of genetic divergence and look for signs of selection. Research findings may be applicable to other marine ecosystems around the planet.

Field Season Overview

In the 2020-21 season, a science team consisting of fourteen participants will travel from Punta Arenas, Chile to the Weddell Sea. Seven target invertebrate species have been prioritized, but other species will also be collected along the continental shelf at depths ranging from 400-600 meters. Sampling may occur down to 1000 meters. Planned shipboard science includes 24-hour operations. Sampling operations at each site will include conductivity temperature depth (CTD) casts, Blake trawls, multicoring, multibeam surveys, and camera surveys. Post-sampling activities will consist of sorting, photographing, cataloguing, and sample processing and storage. All bycatch will be catalogued, stored, and sent back to PI Institution along with samples of the seven target species.

Deploying Team Members