Expressions of Intent for IPY 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Analysis of phytoplankton and macrobenthos assemblages: carbon budgets, taphonomy and food web interactions along the western Antarctic Peninsula shelf.  (Diatoms: Food Web Structure and Carbon Export.)

Outline
It is estimated that at least 40% of Earths net primary production of organic carbon is due to marine phytoplankton. In the Southern Ocean diatoms are the dominant phytoplankton and comprise the bulk of the sediment in the ocean basins around Antarctica. As such, diatoms are central to both food web structure and carbon export in this region. This research will assess how seasonal variability in diatom assemblages impacts on the food web structure and carbon export regime. In the water column diatoms are either grazed, dissolved or sink to the sea floor. In this project we aim to complete systematic surface water, water column and sediment sampling along the Antarctic Peninsula shelf to achieve a comprehensive view of how diatom population dynamics impact on carbon sequestration and success of higher organisms. The study will collect modern diatom, dinoflagellate, zooplankton and macrobenthos assemblages to compare biomass and richness between pelagic and benthic communities. This will afford the potential to address key questions relating to carbon export and food web structure:1) how changes in productivity along the western Antarctic Peninsula impact food web structure, 2) how diatom species dictate carbon export, 3) how taphonomic processes (e.g. dissolution) affect carbon export from the ocean surface, and 4) and the role of macrobenthos in carbon export.Carbon Export: High Productivity in the surface waters and preservation in sea floor sediments means diatoms play a major part in the drawdown of pCO2 and sequestration of carbon into deep-sea sediments. Accumulation of sediments is the only durable sink of organic carbon in the marine system. However, little is known about which diatom taxa deliver organic carbon to the sea floor, how taphonomic processes influence this carbon export and, in an environment dominated by strong seasonal variability, how carbon export by diatoms will be affected by climate change. Food Web: Diatom production sustains large krill populations upon which higher organisms rely. Studies of food web structure around Antarctica have tended to focus on krill and lack the primary data on diatom population dynamics. Recent studies have shown that krill populations rely on summer diatom blooms and extensive sea-ice for winter food from sea-ice diatoms. In the Antarctic Peninsula, seasonal variability of sea-ice is the most important control on diatom productivity. Changes in the sea-ice regime related to regional warming will have a large impact on diatom assemblages and productivity, hence, on food-web structure and carbon export.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
The project aims to assess how diatom population dynamics impact on the Antarctic food web and on export of carbon into Southern Ocean sediments. These aims address key issues relating to sustainability of the Southern Ocean food web and mechanisms of carbon sequestration in a rapidly warming world. These broader themes pertain not only to the current state of the polar environment but also to how climate change in the Peninsula may impact both on a regional and global scale (IPY Themes 1-3). The project employs a novel approach to look at how carbon sequestration occurs as a function of the marine ecosystem (IPY Theme 4) and will provide vital information on the biological control of carbon in the marine system.

What international collaboration is involved in this project?
The project involves a collaboration between scientists at Cardiff University, British Antarctic Survey (UK) and Utrecht University (The Netherlands).

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
We propose to run four transects across the western Antarctic Peninsula shelf. The most southerly to be in Marguerite Bay and the most northerly to run to the north of Bransfield Strait.

Approximate timeframe(s) for proposed field activities:
Arctic: n/a
Antarctic: Oct-Nov 2007      Jan-Feb 2009      

Significant facilities will be required for this project:
Two 19 day cruises (24 hr working) on an ice strengthened research vessel - one spring, one late summer/autumn – equipped for CTD and Sediment Trap deployment, box-coring and trawling. This resource could be shared with other projects that might wish to carry out underway sampling, deployment or recovery of buoys or moorings.

Will the project leave a legacy of infrastructure?
The legacy of this project will be a unique view of carbon cycling in the marine realm and a detailed depiction of the water column ecological structure reflecting both the physical and biological dynamics of a vast area of the Antarctic Peninsula continental shelf.

How is it envisaged that the required logistic support will be secured?

Has the project been "endorsed" at a national or international level?
This expression of intent has been submitted to the UK National IPY Committee.

PROJECT MANAGEMENT AND STRUCTURE

Is the project a short-term expansion (over the IPY 2007-2008 timeframe) of an existing plan, programme or initiative or is it a new autonomous proposal?

This project will build on the results of two AFI CGS projects (CGS99/02 & CGS5/11) which sampled modern summer and spring diatom assemblages during Feb-March 2002 and Nov-Dec 2003.

How will the project be organised and managed?
The project will be organised and coordinated principally by Jenny Pike at Cardiff University with regular formal and informal communication with remaining project members. A large proportion of the analyses will be carried out by the science crew during the cruise and all residual analyses will be completed by project members at their respective institutions.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
Given the importance of the carbon cycle in understanding natural & anthropogenic climate change, and the Southern Ocean food web to support a vast ecosystem, the project should generate wide public interest. Key findings will be disseminated to the scientific community at conference venues and publications, and to the public via the media and public talks..

What are the initial plans of the project to address data management issues (as outlined in the Framework document)?
Cores will be stored at BAS and archived at the British Ocean Core Repository (BOSCORE). Assemblage data will be made publicly available following primary publication.

How is it proposed to fund the project?
Application to NERC AFI.

Is there additional information you wish to provide?
None

PROPOSER DETAILS

Dr Claire Allen
British Antarctic Survey
Madingley Road
Cambridge
CB3 0ET
UK

Tel: 44 (0)1223 221422
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Other project members and their affiliation

Other Information