Climate change and ecosystems in the Southern Ocean

ICED is an international multidisciplinary programme launched in response to the increasing need to develop integrated circumpolar analyses of Southern Ocean climate and ecosystem dynamics.

ICED has been developed in conjunction with the Scientific Committee on Oceanic Research (SCOR) and the International Geosphere-Biosphere Programme (IGBP), is a regional programme of Future Earth’s Integrated Marine Biosphere Research (IMBeR, formerly IGBP’s IMBER programme), and is co-sponsored by SCAR (Scientific Committee on Antarctic Research).

The ICED vision is to develop a coordinated circumpolar approach to better understand climate interactions in the Southern Ocean, the implications for ecosystem dynamics, the impacts on biogeochemical cycles, and the development of sustainable management procedures.

Some of the strongest regional expressions of global climate change have occurred in Antarctica and the Southern Ocean. The physical changes observed have also been associated with variations in Southern Ocean ecosystems. Given the existence of, and potential for, dramatic responses to climate change in this region, developing the ability to predict ecosystem dynamics at a range of spatial and temporal scales is crucial. However, there is added complexity in determining climate impacts in a disturbed system where harvesting has been extensive. Understanding the underlying processes driving ecosystem responses to climate change on a regional and circumpolar basis is necessary to provide a sound basis for the sustainable management of this globally important ocean. The Southern Ocean is also a key component of the carbon cycle, yet global carbon budget models are lacking detail from this region. An understanding of these processes is also necessary to predict the impacts and feedbacks of the Southern Ocean as part of the Earth System.

• Theme 1 – Key physical processes affecting the Southern Ocean

Focussing on the importance of changes in climate processes, sea ice and oceanographic cycles, this theme will address the following key issues: (i) large-scale physical interactions (atmosphere-sea and ice-ocean) and their connections with Southern Hemisphere climate related processes, (ii) long-term trends in these interactions and their effects at regional and circumpolar scales.

• Theme 2 – Interaction of physical and biological processes and their effects on nutrient dynamics and biogeochemical cycles in the Southern Ocean

Focussing on the influence of ecosystem structure on biogeochemical and nutrient cycles, this theme will address the following key issues: (i) interannual variability and regional variation in nutrient dynamics and biogeochemical processes, (ii) links between biogeochemical cycles and food web structure, (iii) depth-related vertical links in food webs, and (iv) life histories of lower trophic level species

• Theme 3 – Structure of Southern Ocean ecosystems

Focussing on the structure of Southern Ocean ecosystems, particularly the links between at lower and higher trophic levels, this theme will address the following key issues: (i) decadal changes in the distribution and abundance of key species and of the ecosystem as a whole, (ii) energy transfer to higher trophic levels via pathways other than Antarctic krill, (iii) spatio-temporal variations in food webs, (iv) links between the mesopelagic food web and higher trophic levels, (v) links between benthic and pelagic systems, (vi) life histories and interactions of mid and upper tropic level species, and (vii) determining the scale of key physical and biological process interactions in ocean ecosystems.

• Theme 4 – Southern Ocean ecosystem structure and dynamics in the context of sustainable management plans

Focussing on developing strong links with CCAMLR and providing it with scientific data to develop its ecosystem approach to management, this theme will address the following issues: (i) ways in which to utilise knowledge of Southern Ocean ecosystems in a management context, (ii) how to take into account the complexity of these ecosystems in developing simple and pragmatic management approaches, and (iii) principles for using data for monitoring purposes.

• Theme 5 – Circumpolar models (forecasting ecosystem response to climate and other anthropogenic forcings)

Focussing on the status and development of atmosphere-sea, ice-ocean and biogeochemical models, this theme will address the following key issues: (i) development of physical models, (ii) life history models, (iii) food web models, (iv) complex biogeochemical models, and (v) realistic ecosystem models at the circumpolar level.