University of Texas Austin
Insitiute for Geophysics
Supporting Stations: McMurdo Station
Research Locations: McMurdo Ice Shelf
We requested 19 science days of shared ship time (R/V Gould) for benthic and plankton sampling along the southwestern portions of the Antarctic Peninsula into the Bellingshausen Sea. We anticipate a round trip from Punta Arenas, Chile.
We have been approved for 6 berths funded by NSF and hope to add up to 8 additional berths pending NSF approval (Expenses for travel and medical will be covered by the grantees and not NSF.) Leaving from Punta Arenas, we will transit to the Antarctic Peninsula and we assume we will have to stop at Palmer station (but the schedule is still in flux). From there will proceed to Marguerite Bay then south and east into the Bellingshausen Sea as ice and weather permit.
Our goal is to sample as broad a geographic breadth as possible. We consider sampling opportunistic and we do not have exact locations. Instead we take what the ice will give us; in other words we will stick to the ice edge. On previous cruises this flexibility has yielded useful results. Thus we typically avoid the ice when possible.
If extra berths are approved, we will have sufficient personnel to work with 2 teams in shifts (thus maximizing shiptime). If only 6 persons are approved we will only be able to run one shift a day.
Sampling will consist of mainly of benthic sled and trawl type devices. The Blake trawl will be our workhorse, but well will have several pieces of equipment as backup (e.g., Agassiz trawl, rock dredge,box core, multicore, Van Veen). We will also use the Yo-Yo camera to conduct bottom transects. If possible a few planktonic samples may be obtained. If there are questions or concerns about what we can do/need to do, please contact Halanych and he can provide more details.
Field Season Overview:
The overarching goal of the proposed work is to provide an evolutionary understanding of how marine benthic organisms (including their larvae) are genetically structured and physically distributed in the Western Antarctic. This information will have direct implications for understanding past and future range shifts of organisms. In particular, we will examine larval distributions and assess if distributions are consistent with patterns of genetic connectivity within Antarctic waters. To this end, we will employ an integrative approach that focuses on the genetic signatures of historical gene flow or isolation.
These data will be examined in light of known processes in Antarctic waters that potentially influence advection of larvae around Antarctica. Hypothesis: Herein, our objectives are designed to test a major, but poorly explored, assumption about Antarctic biology: Ho = Antarctic species of benthic invertebrates have sufficient gene flow to maintain broad, possibly circumpolar, panmictic distributions.
Using this generalized null hypothesis and by examining multiple species with different life histories, we have begun to build a more holistic view of the factors controlling Southern Ocean biodiversity, biogeography and evolutionary history.
Deploying Team Members: