Expressions of Intent for International Polar Year 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

DOC variations in polar pelagic ecosystems and their relation to trophic control mechanisms and diversity in polar microbial food webs.  (Polar DOC and microbial food webs)

Outline
We will focus on the biological mechanisms related to the balance between production and consumption of DOC in polar regions, with particular emphasis on the potential effects of reduced ice cover. The main consumers of DOC in the pelagic are the heterotrophic bacteria. The bacterial carbon demand (BCD) can be factorized according to the equation BCD=µB/Y where µ is growth rate, B is biomass, and Y is growth yield. According to present understanding, bacterial growth rate can be limited by either the supply of degradable organic material (C-limitation), or by mineral nutrients such dissolved inorganic or organic nitrogen, phosphate or iron (mineral nutrient limitation). The two cases represent very different types of control of bacterial activity: In the C-limited case, bacteria will mineralise degradable DOC as fast as it is produced. Temperature dependence of BCD thus must be a question of the temperature dependence of DOC producing mechanisms in the food web, and any accumulation must be caused by the production of recalcitrant forms of DOC. In the case of mineral nutrient limitation, BCD becomes a function of how bacterial growth rate is controlled by algal-bacterial nutrient competition, how bacterial biomass is controlled by predation, and how growth yield varies with factors such as temperature and growth rate. The balance between production and consumption of DOC is closely related to the structure of the pelagic food web. Reduced ice cover causing increased light influx obviously increases algal competition for mineral nutrients and presumably stimulates DOC production. Since viral lysis is thought to be one important mechanism shunting material to the DOC pool instead of upwards along the predatory food chain, lytic viruses represent a direct link between control of diversity (richness) and DOC production. In such a conceptual framework, species richness becomes a top-down controlled property determined by lysis and predation. The species occupying these niches would to a larger extent be expected to be bottom-up controlled with specialists for different limiting substrates dominating the community. If this is true, species composition would be expected to change with the type of limitation experienced by the bacterial community. The Southern Ocean has the potential feature of Fe-limited bacterial growth. For comparative purposes we propose to study the outlined relationships during participation on one cruise in the Arctic and one in the Antarctic. For experimental work on the microbial pelagic food web, we propose a mesocosm study at Ny Ålesund.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
The project will contribute to the quantification and understanding of the biological processes that form the basis of the food webs and the driving forces of the biogeochemical cycles in the polar marine environment. Furthermore the difference in the dynamics of the Southern and Northern marine microbial food webs will be investigated. The biogeochemistry of the two polar oceanic regions has profound influence on the rest of the world’s ocean.

What international collaboration is involved in this project?
Two international partners are identified and have expressed interest in active cooperation with the Norwegian group. 1) The University of Kalmar, Sweden. Contact person: Professor Åke Hagström. 2) National Research Institute, Department of Marine Ecology, Roskilde, Denmark. Contact person: Professor Torkel Gissel Nielsen.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
Open ocean studies: North: Barents Sea - Arctic Ocean Transect (30oE, 75-85oN (alternatively 75oN – ice edge)). South: Antarctic Convergence – Ice edge Transect (0oW, 50-70oS). Experimental studies: Mesocosms at Ny-Ålesund, Svalbard (78° 55' N, 11° 56' E) or Disco Bay, Greenland (69°15′N, 53°33′W).

Approximate timeframe(s) for proposed field activities:
Arctic: 09/07 – 11/07      08/08 – 09/08      
Antarctic: 12/07 – 02/08            

Significant facilities will be required for this project:
The mesocosm studies will be located at Ny Ålesund or Disco Bay, where laboratory and accommodation facilities are available. Equipment for the experiments will have to be built and installed by the project. Two oceanic expeditions are planned: 1) The Arctic ocean, requiring laboratory space and accommodation for 10 researchers on an icebreaker (if an icebreaker is not available the cruise transect will end at the ice edge). 2) The Southern Ocean, requiring laboratory space and accommodation for 3 researchers onboard. The oceanic part of the project will seek cooperation with physical oceanographers and marine biologists for optimal use of resources and we foresee joint cruises with other research groups.

Will the project leave a legacy of infrastructure?
Equipment for mesocosm studies will be available for later research, however the most important legacy building consists of educating new personnel experienced in this type of arctic field work, and the understanding of polar marine microbial food web which can form a basis for further research.

How is it envisaged that the required logistic support will be secured?
Another national polar operator

If the project is funded we anticipate oceanic expeditions organized on a national level.

Has the project been "endorsed" at a national or international level?
No. The letter of intention will be presented to the Norwegian National Committee for Polar research and to the Norwegian IPY representative concurrently with the submission of the letter of intent to IPY.

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?
New

The project will depend on the initiation of a new activity which will form the core project at the Department of Biology. Other existing project at the Department is expected to add activity within the consortium planned. In addition, cooperation is sought with international partners with separate funding.

How will the project be organised and managed?
The project is anticipated as a consortium consisting of a core project and several subprojects with separate funding. The core project will focus on the main objectives identified and in addition be responsible for field work planning and logistics. The core project will be established at the Department of Biology, University of Bergen. Cooperating projects with their own specific aims that adds to the main objective will be sought both within the institution and elsewhere. So far, two international partners have been identified.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
The core project will employ two doctoral students. Furthermore the results from the project will be actively used in the teaching at the Department of Biology. The attention of the media will be actively sought, and activity and results will be presented on web-pages in a popular form.

What are the initial plans of the project to address data management issues (as outlined in the Framework document?
Quantitative data will be stored electronically in worksheets or databases and made available to IPY-databases as required. Qualitative data (images, descriptions) will be stored electronically, listed in a www-searchable database and made available on request. Biological material will be deposited in genbanks, biobanks, clone librarys, and culture collections as required.

How is it proposed to fund the project?
The core project at the Department of Biology will depend on funding from the research Council of Norway, and a proposal will be submitted in June 2005. On a later stage, possibilities for funding will be sought at the EU commission.

Is there additional information you wish to provide?
The project will form a basis for continued research activity on polar microbial food webs extending the IPY period. Given the present state of understanding of the characteristics of the polar marine microbial food web dynamics, the need for further research investigations is anticipated, especially regarding the effects of climate change on the production processes and the biogeochemical cycles in the polar regions, and their interactions with the rest of the global marine ecosystems and the atmosphere.

PROPOSER DETAILS

Prof Gunnar Bratbak
Jahnebakken 5
B.P. 7800
Bergen
NO-5020
Norway

Tel: +47 55 58 26 58
Mobile: +47 97 01 87 91
Fax: +47 55 58 96 71
Email:

Other project members and their affiliation