A better understanding of ocean climate and ecosystems, as well as human impacts and vulnerabilities, requires the implementation and coordination of a continuous and long-term system of ocean observations. Existing observation frameworks for physical oceanography and marine ecosystems reveal significantly higher observation effort in the North Atlantic than in the Tropical and South Atlantic. Understanding of the status of the Atlantic ecosystem thus requires additional discipline specific and dedicated observational efforts in some regions.

In this context, TRIATLAS CT1 will enhance the implementation and coordination of ocean observations in the South and Tropical Atlantic critical for three major goals: climate, operational services, and marine ecosystem health. These goals correspond to the Belém agreement on Atlantic Research and Innovation Cooperation to contribute to a coordinated and partnership-based approach to tackle the scientific and societal challenges of the Atlantic Ocean based on the principles of shared responsibility and mutual benefit in ocean observation, technology innovation, forecasting and monitoring processes and systems to assess climate variability and develop ecosystem approaches devoted to ensure food security, fisheries and biodiversity managements.

Core Theme Leader: Heino Fock, TI
Core Theme Co-Leader: Peter Brandt, GEOMAR

The work in CT2 encompasses a systems perspective, analysing and synthesising physical, ecological and human social variability and change into a coherent whole for three case studies where we believe the database is sufficiently strong. CT2 will examine ecosystem variability in response to large scale circulation variability and its impacts, including contributions to oceanic stratification and oceanic heat and freshwater transports, quantities that we expect to vary under climate change. This is a novel use of the trans-Atlantic circulation observations (such as SAMOC at 34.5S and RAPID at 26.5N) which will give us the ability to validate this response and variability in our models for the first time.

The explicit inclusion of human social drivers in a marine social-ecological approach is beyond state-of-the-art in the southern hemisphere and in many regions in the northern hemisphere as well. While ecosystem regime shifts are beginning to be understood, the potentially vast ramifications for management of human activities in the ocean are far less researched, both from a human social and natural science perspective. We will contribute novel approaches to management advice accounting for potential regime shift in the different case studies.

We will develop a model intercomparison exercise using available ecosystem models to examine past changes in regional systems, using the standardized protocol of the Fisheries and Marine Ecosystem Model intercomparison project (FishMIP). A series of suitable indicators will be analysed to compare among model types, and among case studies drawing from both observational and model results. This methodology is very much at the forefront of science globally, and the outcome will be beyond state-of-art.

Core Theme Leader: Elaine McDonagh, NORCE
Core Theme Co-Leader: Astrid Jarre, UCT

CT3 will go beyond the present state-of-the-art by bringing together climate and marine ecosystem modellers who will join their efforts to integrate several ESMs, ecosystem and fisheries models into a multi-model climate-to-fish prediction framework over the whole Atlantic Ocean. For this, CT3 will benefit from the observational network and products from CT1 and from the understanding of the ecosystem-climate links studied in CT2.

For the first time, physical (atmosphere and ocean), biogeochemical, ecosystem and fisheries predictions from seasonal to decadal timescales will be implemented to deliver tailored information of future marine ecosystem evolution and its associated uncertainty. In complement to these novel short to mid-term predictions, long-term scenarios simulations driven by RCPs and the SSP-based fishing effort scenarios developed (with stakeholder input) in CT4 will also be realized. Both predictions and scenarios will be made available to scientists, stakeholders and the wider public in South Africa, Brazil, and other countries bordering the Atlantic Ocean and interested in the evolution of marine ecosystems and fishery resources.

Core Theme leader: Roland Séférian, CRNM
Core Theme co-leader: Emilia Sanchez-Gomez, CERFACS

Future fishing opportunities are not only determined by the change in production and distribution of fish stocks through climate change, but also by changes in technology and changes in the demand for fish, mainly driven by population growth and changes in income (Quaas et al. 2016). As fish is a highly traded food commodity, this is not only affected by local, but also global changes. The Shared Socioeconomic Pathways used by the IPCC are used to develop global scenarios.

To understand local effects and changes, TRIATLAS will contextualize the SSPs for the first time for the case study areas and marine activities, mainly fishing (CT4). TRIATLAS will go beyond an interdisciplinary approach by engaging with stakeholders to co-produce the scenarios and gather input for the conceptual models. This will also ensure a dialogue for better uptake of project results by practitioners and decision makers.

With the output from ecosystem models and the collection of social and economic data on a community level, impact assessments will be performed and the output used to inform policy makers in the case study regions. The increasing demand of fish for human consumption will likely require changes in the use of some species, which are currently used to produce fish meal and oil for feed. A change from a reduction fishery towards a human consumption fishery will have profound effects on the value chain. TRIATLAS will advance the understanding of necessary changes and their effect in the value chain.

Core Theme Leader: Hans Sloterdijk, CAU
Core Theme Co-Leader: José H. Muelbert, FURG