A – Ocean Observations and Modelling
A1 – The ocean carbon cycle at a time of change: data syntheses, analyses and modelling – Nicolas Gruber; Jeremy Mathis; Toste Tanhua; A. Lenton; I. Kriest
The ocean carbon cycle is changing at a rate whose magnitude and pattern we are only beginning to document, quantify, and understand. The uptake of anthropogenic CO2 from the atmosphere, climate fluctuations as well as long-term trends in ocean circulation and biology have led already to substantial changes in the ocean carbon cycle, with potentially larger changes looming ahead.
In the last decade, substantial efforts have been undertaken to measure these carbon cycle changes, and a number of projects are underway to synthesize them and to put them into the context of climate variability and change (e.g. international synthesis activities associated with the SOLAS-IMBER carbon working groups and IOCCP, including SOCAT, CARINA and PACIFICA, for example, but also those undertaken in the context of RECCAP). Despite these efforts, large and potentially very significant regions of the ocean remain under-sampled. Consequently different approaches such as global and regional biogeochemical models are playing an increasingly important role in such syntheses, e.g., for the development of specific hypotheses, process understanding, future projections, and to contextualize observed changes with respect to projections. The different biogeochemical equations (or formulations) implemented across biogeochemical models mean that the structure and set up of these models is very diverse and they are not always examined over the full range of possible biogeochemical setups. This requires a thorough assessment of these models by observations.
This session aimd to bring together the scientists working on these synthesis and model evaluation projects, but was open to all other scientists who are interested in developing an integrated view of how the ocean carbon cycle has changed in the recent decades. Of interest are data syntheses, analyses and modeling studies focusing on air-sea CO2 fluxes, changes in ocean surface and interior carbon properties, and how the changes in these realms are connected to each other. To address and discuss the uncertainty prevailing in the setup and response of global and regional biogeochemical models, we also invited contributions related to their assessment, including the definition of metrics and data sets suitable for comparison.
The primary audience was the scientists interested in observing and simulating the ocean carbon cycle, from the global to the regional scales, but we also wanted to target people interested in ocean acidification, ocean deoxygenation, and other local to global stressors to the marine systems.
A2 – Synthesis of ecological and biogeochemical variability determined from time-series Eulerian and large spatial scale transect observations – Carol Robinson; Andy Rees
Achieving a quantitative understanding of how marine biogeochemical cycles and ecosystems interact is a prerequisite to understand how this coupled system affects and is affected by climate and environmental change. A number of decadal time series stations, including the Hawaii Ocean Time-Series (HOT) and DYFAMED, and large spatial scale transects, such as Galathea 2006, Malaspina 2010, and the Atlantic Meridional Transect (AMT) have accumulated unprecedented observations of the interplay between food webs and biogeochemical cycles across gradients of temperature, nutrient supply and light availability. They have also provided the context for manipulation and bioassay experiments to assess the impact of single or multiple stressors including temperature, nutrient supply and pH. This session called for contributions which synthesise these observations, in order to compare and contrast the functioning of marine ecosystems in relation to biogenic export and cycling of climate relevant gases, and to assess their resilience to change.
A3 – Modelling and data synthesis of marine planktonic ecosystems using functional types and trait-based approaches – Scott C. Doney; Meike Vogt; Mick Follows; Thomas Kiørboe; Øyvind Fiksen
Recent advances in field data sets, satellite remote sensing, and numerical modelling are opening up new avenues for characterizing marine planktonic organisms and ecosystems. This session will bring together new data synthesis efforts and modeling studies focused on phytoplankton and zooplankton functional types or traits. Topics will include spatial distributions, ecological niches, phenology and succession, food web interactions, community composition and size class structure, and taxonomic, functional or trait-diversity in models and data.
The session explored links between present and future marine plankton community composition and marine ecosystem services, for example the productivity – diversity relationship, and it discussed the use of property – property relationships (emergent constraints) and other new and innovative metrics for model-data inter-comparison. Further topics included the evaluation of ecosystem processes aggregated onto the biome scale, and the extrapolation of data using statistical modelling to overcome data limitations in under-sampled ocean regions, and to explore large scale ecological patterns. Approaches where biodiversity and adaptive responses of organisms are more resolved (trait-based models) across all trophic levels, and in particular studies where traits (properties, behaviour, optimality, and diversity of organisms) and biogeochemistry interacts in forming ecosystem structure.The session presented new and innovative approaches for the analysis of global data sets such as the MAREDAT atlas of global marine plankton biomass, and how such data sets can be used to retrieve information on large-scale ecological patterns in marine ecosystems and to verify important hypotheses in marine ecology that could not previously be addressed. Furthermore, the session showed how different data streams can be synthesized to inform model evaluation and development exploiting emergent constraints and new metrics that go far beyond the validation of global chlorophyll patterns.The session highlighted recent advances in marine ecosystem modelling in terms of complexity and flexibility of the model formulations, and how these models can be used for the quantification of important ecosystem services in the present and future ocean. The session would be of interest for a large fraction of the IMBER community, and will bring together scientists from both the modelling and the observational community. It could be used as a spring board for the coordination of future international marine monitoring projects, and as a base for the exchange of information between modelers and experimentalists on data needs for future model development.
A4 – End-to-end modelling for research and management – Stuart Corney; Jessica Melbourne-Thomas; Andrew Constable
There is now good agreement on what constitutes an end-to-end ecosystem model, and the field has seen rapid advances in recent years. Many different model frameworks are available that resolve, to various levels of detail, interactions between oceanography, the broader environment (e.g. climate or cryosphere), biogeochemical cycles, foodweb dynamics and human industries and markets. In the face of these advances, there is a pressing need to synthesise available tools and approaches, and to identify key gaps that might affect the continued (and increasing) development and use of end-to-end models in decision-making. Such a synthesis is also an important means to avoid duplication of effort.
In this session we aimed to promote an integrated approach across the modelling community in the development of end-to-end ecosystem models. We seeked to synthesise the components, mechanics and applications that exist across the range of end-to-end models now available for marine ecosystems. Through invited and contributed talks and posters we populated a matrix based around these three factors. Importantly, this synthesis aided in identifying specific challenges that lie ahead in attempts to integrate the physical environment, food webs and human components into modelling frameworks useful for management.
B – Lower Trophic Level Processes and Dynamics
B1 – The dark ocean: recent progress in understanding the functioning of the ocean’s largest subsystem – Dennis A. Hansell; Gerhard J. Herndl; Javier Arístegui
The dark ocean is one of the great unexplored realms on Earth, but one that IMBER illuminated during the inaugural IMBIZO in Miami, 2008. The biological pump connects surface processes to the deepest ocean layers, where biological processes occur at very low rates relative to the upper ocean. With deep ocean residences times at centennial to millennial scales in time and global scales in space, the system is only slowly ventilated and circulated. Biogeochemical signals in the deep ocean are integrative of processes occurring over very long periods. Biological processes in the deepest ocean layers are intimately tied to particle dynamics/transformations and microbial food webs, much of which are still only poorly characterized. The central aim of the session was to assess our progress in this domain since the first IMBIZO and to evaluate the role of the dark realm in the light of predicted and observed changes in global ocean’s functioning. Contributions was sought from a wide range of disciplines, including biogeochemistry, organic geochemistry, microbial oceanography including -omics, trace element and isotope geochemistry, particle flux dynamics, and modeling.
B2 – Microbial and geochemical perspectives of global carbon cycling and climate change: from genes to ecosystems, from ancient to current – Farooq Azam; Carol Robinson; Nianzhi Jiao
The role of heterotrophic marine microbes as organic matter decomposers is well studied, but much less appreciated is their role as producers of refractory dissolved organic carbon (RDOC), which can persist in the water column for decades to millennia thus constituting carbon sequestration in the ocean. Such dissolved phase carbon sequestration through microbial transformation of organic carbon from labile to refractory states has been conceptualized as the microbial carbon pump. The RDOC reservoir in the current ocean is almost as large as the entire atmospheric CO2 inventory (and one study has suggested that it may have been much larger in the ancient ocean). Its biogeochemical behaviour is therefore critical for models of global carbon cycling, and there is a need to understand the microbial processes that underlie RDOC production and the factors that regulate this transformation. A major analytical challenge is that the chemical composition of RDOC is unknown, a critical issue in understanding its biogeochemical behaviour. Microbial processes that generate and regulate RDOC production are beginning to be understood in the context of the functioning of the microbial loop. Another challenge is to understand why RDOC is not accessible to bacterial metabolism, and how the molecular composition of RDOC is influenced by the genetic composition of the microbial population. An overarching goal of this session is to conceptually integrate the activities of the MCP and the biological carbon pump. Relevant topics include: molecular biomarkers and isotopic tracers linking water column carbon sequestration and sediment records; field observations and in-situ manipulation experiments to explore the mechanisms explaining the variability in carbon sequestration under a range of nutrient, temperature and CO2 regimes; and ecosystem modelling of RDOC production based on ecological parameters. We welcomed oral and poster contributions addressing these issues of biological carbon sequestration in the ocean and their significance for climate change.
B3 – The pivotal role of the mesopelagic functional groups in biogeochemical cycles – Patrick Lehodey; Dan Costa; and CLIOTOP SSC members
The mesopelagic layer is inhabited by a large biomass of micronektonic organisms providing a source of food for many large predators including exploited species (e.g. tuna) and many protected marine mammals (e.g. seals, whales). In addition to drive the feeding behavior of these large oceanic predators, a large part of mesopelagic organisms undertake nycthemeral migrations to feed on zooplankton and meroplankton including the eggs and larvae of exploited fish in the surface layer. They also contribute to the release of Particular Organic Carbon (POC) that is either recycled by the microbial loop or sink to the deep ocean. Such feedbacks are potentially responsible of a part of variability in the carbon cycle, the oxygen consumption and the biological CO2 pump that is not yet described in ocean biogeochemical models. Despite their pivotal role in the functioning of the oceanic ecosystem very few is known about these components, likely reflecting a lack of economical value. However exploitation of these organisms is now also raising some interest. Developing more research studies on the mesopelagic layer and the role of its micronektonic functional groups is a high priority for IMBER and its programme CLIOTOP that organized a special session on this topic during the conference.
B4 – Ocean biogeochemical dynamics under changing climate: feedbacks and impacts – Christoph Heinze, Are Olsen; Jerry Tjiputra
Global marine biogeochemistry plays a crucial role in the climate system through sequestering surface carbon and maintaining the surface-deep ocean carbon gradient through the so-called solubility and biological carbon pumps. In the IMBER & SOLAS endorsed project CARBOCHANGE and a suite of other projects, attempts are made to quantify the changing ocean carbon dynamics under rising atmospheric CO2and altered climate. How these changes could impact or feedback to the climate system will also play a crucial role for improving future climate prediction. For the session we would like in particular to see presentations on new findings about:
- Quantification of anthropogenic excess CO2 transport into the ocean (spatio-temporal distribution and evolution).
- Where are the fastest changes in dissolved inorganic carbon occurring and what implications may this have on biogeochemistry (e.g. re-dissolution of CaCO3 sediment) as well as on intermediate-depth to deep ecosystems?
- What are the links between changes in ocean circulation/stratification, particle export, and marine particle fluxes (POC, POP, PON, BSi, CaCO3)?
- How will ocean pH drawdown, warming, de-oxygenation, and shifting circulation co-act to induce parallel changes in carbon and nitrogen cycling (with special emphasis also on N2O production)?
- What are the key evolving surface and deep ocean carbon cycle processes that could significantly feedback to the climate system? How can we best measure this in the real world?
Modelling, analytical, as well as methodological studies was welcomed.
C – Higher Trophic Level Processes and Dynamics
C1 – Beyond ‘Z’: what modellers need and empiricists have to offer to better incorporate higher trophic levels and humans in end-to-end models – Alistair Hobday; Kevin Weng; Joel Llopiz
C2 – Not so simple: developing robust approaches to the use of indicators for ecosystem based fisheries management – Alida Bundy; Yunne-Jai Shin; Lynne Shannon
Ecosystem based approaches to fisheries and ocean management require the integration of information on the broader ecosystem and human dimensions. To progress towards effective ecosystem-based fisheries management, the scientific community has emphasised the development of indicator-based approaches to track and evaluate the ecosystem effects of fishing and the effectiveness of management measures to maintain resources in a sustainable form. Ecosystem indicators aim to reflect key ecosystem processes; they serve as signals that something more fundamental or complicated is happening than what is actually measured. Further, they can provide information about key thresholds or tipping points, beyond which the sustainability of an ecosystem is severely compromised or the ecosystem state is drastically, perhaps irreversibly, altered.
There is now a wealth of ecosystem indicators proposed by the scientific community and frameworks have been developed for careful selection of indicators and evaluation of their relevance. However, as the world moves closer to implementing ecosystem-based fisheries management, it has become clear that, like single species assessment and management, ecosystem-based fisheries management requires quantitative methods and criteria that can be used to assess overall ecosystem status, evaluate trade-offs among ecosystem services, and guide management actions in a global change context. The use of reference points has gained great traction in single species management, and is of particular importance in the Precautionary Approach. However, few reference levels, with associated decision criteria have been defined for ecosystem indicators.
The key questions that we addressed in this session was “what is the relationship between fishing, ecosystem indicators, ecosystem state and global change” and “how can this information be implemented in a management context”. We invited papers that explore the following areas using modelling and/or statistical analyses:
- Identification of reference levels for ecological indicators
- Performance testing of ecosystem indicators and reference levels for detecting deterioration in states
- Identification of tipping points and thresholds beyond which ecosystems are altered
- Linking of thresholds with indicators and decision theory to develop tools for ecosystem-based management
- Methods for integrating across a broad suite of indicators (e.g. climate, ecological, human dimension) to establish ecosystem status and response to global change
C3 – Integrated studies of the impact of climate change on marine ecosystems – Sakina-Dorothée Ayata; Rubao Ji; Trond Kristiansen; Gabriel Reygondeau; Yunne Shin; Øystein Varpe
Climate-related changes in the oceanic physical environment have been considered as major drivers for shifts in phenology of marine species, distribution and productivity of phytoplankton and zooplankton, and are then expected to strongly affect ecosystem services such as fisheries. And as a consequence, changes in the abundance and spatial distribution of commercially important fish stocks can have significant consequences for communities and economies from local to international scales. As climate models have been developed and coupled with ocean physics, attempts are now made to include ecosystem dynamics in order to assess the potential changes in biological production, from low to high trophic levels, in response to global change.
This session aimed to discuss potential routes towards understanding the complex interactions and mechanisms between changes in physics and biology at multiple trophic levels. Indeed, the scientific community is becoming increasingly aware of the need for ecosystem-based assessments to account for multiple stressors, such as climate change, overfishing, pollution, habitat destruction, and species invasion. A requirement for gaining new insight into complex marine ecosystems requires expertise in a broad range of fields, such as climate science, ecology and fisheries oceanography. We need to combine different approaches across scientific disciplines to tackle the questions that human societies are facing in the context of global ecosystem modifications.
The central idea of this session was then to present integrated studies of the impact of climate change on marine ecosystems, from lower trophic levels to fish and towards Ecosystem Based Fisheries Management. It would especially include the impact of global change on plankton production, recruitment of early life stages of fish, and habitats and biogeography of key species of marine ecosystems. This session strongly encouragesed the presentations of innovative methods (using in situ datasets and/or coupled models), such as the recent developments of IBM, larval dispersal and connectivity models, habitat modelling and eco-regionalization, satellite-derived description of planktonic communities, or end-to-end models, with a special emphasis on combining approaches.
D – Ocean Sustainability
D1 – Marine environmental status and biodiversity: from structure to functionality, delivering ecosystem services – Angel Borja; Alice Newton
Marine biodiversity is central to ecosystem function and ecosystem services on which human welfare depends, i.e. production of food and raw materials, pharmaceuticals, ecotourism and leisure, etc… Multiple pressures from Human activities affect the environmental quality of our seas and oceans and also marine biodiversity. Contemporary marine policies and management worldwide therefore now include the assessment of marine biodiversity and the status of the marine environment.
The proposed session explored:
- the assessment of marine environmental status, ocean health, and marine biodiversity;
- the effect of multi-stressors (drivers and pressures) and the impact on ecosystem services delivery and human welfare;
- policy implications and how emerging knowledge can support policy responses.
D2 – Communities of practice for supporting long-term sustainability of the world’s oceans – Oran Young; Luis Valdes; Isabel Torres de Noronha; David Vousden; Ruben Zondervan; Robin Mahon; Marion Glaser; Suzanne Lawrence; Peter Fox; Leopoldo Cavaleri Gerhardinger
Global ocean governance needs to address the sustainability challenges of the 21 century. This requires linking natural and social science knowledge with that of decision-makers and ocean users in business and civil society in order to deliver science and knowledge to the governance process for more timely and effective adaptive management. There is thus a large number of individual and organisational actors engaged in the fields of knowledge generation and governance and management relating to the global oceans. Members of the recently initiated “Future Ocean Alliance” understand effective ocean governance as requiring an operational global social network which effectively links ocean governance actors across sectors, issues, regions, disciplines and interest groups. Our session will also invite the presentation of case examples on how to generate connectivity in ocean governance at various levels of the Earth system from the regional to the global (eg Agulhas and Somali Current Large Marine Ecosystems Project, Western Indian Ocean Sustainable Ecosystem Alliance; Caribbean LME project; LOICZ). The session was accompanied by a world café type of participatory exercise in which all will be invited to engage in a digitally supported systematic mapping of ocean governance actors and their linkages. The developing global network will be made visually available during the course of the conference. A final discussion panel examined first results at the end of the conference. This sat the scene for building a global alliance for ocean governance and also for producing a published analysis of the state of world ocean governance today.
D3 – Responses of society to marine and global changes as a core mandate for IMBER: ways forward (co-sponsored by PICES) – Alida Bundy; Ian Perry; Bernhard Glaeser; Thomas Therriault
We live in a complex, interrelated world where human activity is creating global, and in particular ecosystem, change at an unprecedented rate; and it is coming back to bite us. Meanwhile, we are tackling the issues created by global change from various perspectives that can be broadly classified as the natural sciences and the social sciences. Within each, a diversity of disciplines are addressing these problems, but they tend to do so in isolation. This is particularly the case for marine ecosystems, where scientists such as physical oceanographers, biogeochemists, anthropologists, and sociologists, have had little opportunity to work together. This is despite being interested in the same issues, such as what are the drivers and impacts of global change, what are the responses by societies, and what ultimately is the effect on the vulnerability and livelihoods of coastal and fisheries dependent communities? Although they approach this question from different perspectives, their questions are connected and interrelated, and understanding the challenges posed by the various dimensions of global change requires an integrated, interdisciplinary (even transdisciplinary) approach.
This is being increasingly recognised by funding agencies and scientists who work at the interface of the natural and social sciences, and is central to the Future Earth Initiative. IMBER has also recognised this and has lately embarked upon its 4th theme, “Responses of Society”, with the formation of a Human Dimensions Working Group. Yet the IMBER community has not wholly embraced the need for an integrated, interdisciplinary approach to address the challenges of global change. There are many reasons for this. We proposed a one day session to:
- discuss what types of global change questions require an integrated, interdisciplinary approach
- explore how projects such as IMBER can cross the threshold of disciplinary boundaries and forge working relationships in interdisciplinary teams to co-produce knowledge and understanding
- discuss the concept of ocean ecosystem services: their utility for future governance and
- present ADAPT, a decision making and analysis tool developed by the IMBER Human Dimensions WG, as an example of an integrated, interdisciplinary approach to provide advice on societal response to global change.
We solicited papers that:
- explore global change questions from an integrated, interdisciplinary approach,
- discuss how the natural and social sciences can inform each other when addressing global change questions, or
- explore methods/approaches that are promising to address these questions.
We especially invited papers that focus on biogeochemical processes (eg., the effects of acidification, environmental pollution, and growing areas of hypoxia and eutrophication) or issues around fisheries and aquaculture, and offer examples of integrated approaches to mitigate the effects of global change on the vulnerability and livelihoods of coastal communities.
This was followed by a panel discussion where natural and social scientists was invited to comment on what they have heard during the session, on the state of the science, what may be missing, and finally, to suggest ways forward for IMBER.
D4 – Future Oceans’ stewardship: roles, responsibilities and opportunities in small-scale fisheries – Ratana Chuenpagdee; Patrick McConney
In ‘Future Oceans’, stewardship initiatives are going to be in high demand, given resource crises, sustainability challenges and the increasing stresses on ecosystems. Integration of knowledge from a range of scientific disciplines and interactions with policy makers and managers are required for enhancing effective stewardship.
As part of a major research initiative on small-scale fisheries, Too Big to Ignore (TBTI), this session was organized to address three (3) inter-related components concerning ecology, monitoring and stewardship guided by the following questions:
- How do, and will, small-scale fisheries and aquatic environments impact upon each other? This includes technology, by-catch, biogeochemical processes, climate change and other factors.
- What integrated practical systems for monitoring and evaluation exist, or need to be developed, to address these impacts? This includes indicators and participatory processes among others.
- What institutional arrangements for stewardship exist, or need to be developed, to allow small-scale fisheries to be responsible, adaptive and resilient social-ecological systems? This includes fishery organisation capacity, incentives and conservation ethics.
The presentations and discussion focused on success stories and ways of integrating ecology, monitoring and stewardship for the sustainability or rehabilitation of small-scale fisheries globally.
D5 – Tracking for conservation – Claudio Campagna; Daniel Costa
The development of new and innovative technologies has enabled advances in our understanding of marine systems. Recent developments in tagging and tracking technologies have enabled us to gain insight into the movements and behavior of otherwise cryptic marine organisms. As marine animals do not recognize political boundaries, knowledge of their movement patterns and where they perform vital activities such as foraging and breeding can provide the basis for regional management plans. Such information is critical for identifying key habitats for implementation of both marine protected areas (MPAs) and determining the spatial and temporal extent of such management measures.
The session explored the use of satellite tracking data of marine predators for the creation of marine protected areas and for the management of ecosystems. Experts in research, data analysis and conservation action developed a list of good practices in the application of tracking data to conservation. The output of this session helped guide the work of researchers that would like to do conservation science, but who are unclear as how to best apply their research to decreasing a threat or increasing protection of a species or a specific geographic region.
E – IMBER Regional Programmes – Synthesis and New Research Directions
E1 – Changing ecosystems in Subarctic and Arctic regions – Franz Mueter; Sei-ichi Saitoh; Ken Drinkwater
Recent changes in the physical environments of the Subarctic and Arctic regions have been some of the largest in the world’s oceans. These have included warming seas and unprecedented changes in the Arctic sea ice. These changes have led to modifications to the marine ecosystems from plankton production to large marine mammals. Primary production in the northern regions has been increasing due to less ice and a longer production cycle. Several species of zooplankton, fish and marine mammals have been changing their distribution with most of these extending their geographic boundaries farther north. At the same time, the reduction of sea ice has produced hardships for walruses and polar bears. Such changes are also affecting fishing activities and indigenous communities.
The objectives of the session was:
- to highlight the research of ESSAS,
- to document ecosystem changes in the Subarctic and Arctic,
- to present improved understanding of ecosystem processes,
- to generate future ecosystem scenarios under climate change and
- to examine the links between the natural and human systems.
E2 – Detecting, projecting and managing the impacts of change in Southern Ocean ecosystems – Rachel Cavanagh; Keith Reid; Nadine Johnston; Andrew Constable; Eileen Hofmann; Eugene Murphy
Southern Ocean ecosystems are integral to the Earth System, influencing global climate and biogeochemical cycles and maintaining unique biodiversity and ecosystem services. They are currently undergoing rapid climate-driven changes, with far reaching consequences for the rest of the globe. Detection, projection and management of their responses to change, including fisheries-driven change, is therefore crucial for effective stewardship and predicting effects on the Earth System.
To achieve the above requires a range of multidisciplinary approaches including:
- Understanding of ecosystem operation across a range of trophic, spatial, and temporal scales (e.g. from individuals to whole ecosystems, from local to circumpolar, and years to decades);
- Ecological monitoring systems to detect and measure changes;
- A quantified set of scenarios capturing changes in the key physical and ecological parameters of the Southern Ocean and appropriate ecological models to generate projections of future change impacts;
- Sustainable management procedures underpinned by ecological research.
These activities are being led by IMBER’s international and multidisciplinary programme ‘Integrating Climate and Ecosystem Dynamics in the Southern Ocean’ (ICED) and the international body responsible for the conservation of Antarctic marine ecosystems, the ‘Commission for the Conservation of Antarctic Marine Living Resources’ (CCAMLR). This multidisciplinary session, proposed by ICED and CCAMLR, brought together scientists interested in ecology, management and protection to address the impacts of change and effective stewardship in the Southern Ocean as part of the global system. It built on recent ICED activities on ecological monitoring, food webs studies, regional and circumpolar ecosystem syntheses, and model projections. It also built on CCAMLR’s ecosystem-based approach to monitoring and management and consider pelagic ecosystem science required for future IPCC assessments. The aims was to:
- Consider understanding and developments in Southern Ocean ecological monitoring systems and ecosystem operation and interaction across a range of trophic, spatial and temporal scales, including end-to-end views and current understanding of the impacts of change in the Southern Ocean;
- Consider developments in quantified physical and ecological scenarios, ecological model development and projections of future change impacts;
- Consider scientific requirements for monitoring and management, specifically for input to CCAMLR, SCAR and IPCC.
E3 – Biogeochemical and ecological impacts of boundary currents in the Indian Ocean – Raleigh R. Hood; Lynnath E. Beckley; Jerry D. Wiggert and Michael J. Roberts
Boundary currents mediate the transfer of global and regional forcing to local coastal scales. In this process, they fundamentally alter biogeochemical fluxes and ecosystem processes. In the northern Indian Ocean, several boundary current systems are seasonally reversing (e.g., the Somali Current, West and East India Coastal Currents, and the Java Current). These reversing surface currents are unique to monsoon-driven systems and although their transports are relatively small, they have profound biogeochemical and ecological impacts. The southern Indian Ocean currents (Agulhas and Leeuwin) both flow poleward throughout the year. The transport of the downwelling favorable Leeuwin Current is also relatively small, but the poleward direction is unique among eastern boundary currents and it has many unusual biogeochemical and ecological signatures. In contrast, the transport of the upwelling favorable Agulhas Current system is huge and strongly influences upwelling processes, their variability and higher trophic level behavioral responses. The Agulhas is also uniquely complicated by the landmass of Madagascar.
This session highlighted past and ongoing studies related to research theme 1 of the SIBER (Sustained Indian Ocean Biogeochemistry and Ecosystem Research) regional programme. Specifically, we compared and contrasted the biogeochemical and ecological impacts of boundary currents in the Indian Ocean focusing on the influence these currents have on:
- upwelling, downwelling, nutrient supply and primary production,
- filament and eddy generation and their role in biogeochemical and ecological processes, and
- higher trophic level responses including spawning behaviour, larval transport and fate.
F- Regional Studies – Responses to Drivers and Stressors
F1 – Climate-biogeochemistry interactions associated with open-ocean oxygen minimum zones – Andreas Oschlies; Véronique Garçon; Lothar Stramma
There is mounting observational and modelling evidence for an ongoing decline in marine oxygen levels and associated expansion of oxygen minimum zones in the tropical oceans. This session invited contributions that:
- address how subsurface dissolved oxygen responds to variability in ocean circulation and ventilation,
- examine potential sensitivities and feedbacks linking low or variable oxygen levels, key nutrient source and sink mechanisms and, eventually, climate,
- investigate the magnitudes and time scales of past, present and likely future variations and
- the influence on the ecosystem.
The session aimed at bringing together researchers from different disciplines studying a broad range of aspects linked to ocean deoxygenation, and covering observational, experimental and modelling studies.
F2 – Regional responses to climatic and non-climatic drivers in a high-CO2 ocean – Patrizia Ziveri; Sarah Cooley; Minhan Dai; Jean-Pierre Gattuso
The oceans provide fundamental marine ecosystem goods and services to humans’ well-being by offering food, livelihoods and recreational opportunities, and by regulating the global climate. This session covered ongoing and planned initiatives investigating the regional and basin scale impacts of climatic and non-climatic drivers on marine ecosystems. The session focused on the accumulation of the anthropogenic greenhouse gas CO2 in the atmosphere, which has significantly risen since the inception of the Industrial Revolution and increased radiative forcing and warming. The increased concentration of CO2 in the atmosphere is also increasing dissolved CO2 in the surface ocean and causing rapid changes in seawater carbonate chemistry and oxygen concentration (ocean acidification and deoxygenation). We welcomed contributions addressing the biological, ecological and biogeochemical impacts of multiple climatic and non-climatic drivers. A special focus was the regional vulnerabilities of the human-environment system to the combined effect of resulting physical and biological changes that disturb the capacity of coastal and marine systems to provide ecosystem services, and which consequently affect economic activities and human welfare.
The session format included oral and poster presentations as well as a discussion slot focusing on the intercomparison of regional studies and programmes.
F3 – Impacts of anthropogenic stressors and climate change on biogeochemistry-ecosystem in continental margins and feedbacks to earth system and society: Challenges and solutions – Jing Zhang, Hiroaki Saito, Se-Jong Ju, Rosamma Stephen, Helmuth Thomas, Kon-Kee Liu
Despite their importance in providing key ecosystem services and goods, continental margins are facing severe threats from direct anthropogenic forcing and stressors induced by or related to climate change, such as over fishing, reclamation for urban development, discharges of domestic and industrial wastes, warming, de-oxygenation, ocean acidification, increased vulnerability to extreme events, and sea level rise.
The boundary current systems play a vital role in transporting and transforming material in the ocean, but they are vulnerable to global environmental change. The Eastern Boundary Current Systems, where upwelling often brings rich fishery resources, but also the CO2-rich, O2-depleted waters from depth. This makes these ecosystems particularly vulnerable to ocean acidification and de-oxygenation. Warming and elevated river discharge due to accelerated water cycle will undoubtedly enhance stratification in the ocean causing significant changes in all boundary current systems with potential devastating consequences on global biogeochemical cycles and food webs. Most notably stratification may lead to reduction of primary productivity and fisheries resources. In addition, the capacity of continental shelf pumps (i.e., CO2 sink) will likely diminish with time. In near-shore regions throughout the world, there have been increasing incidents of hypoxia, degradation of water quality, harmful algal blooms (HAB), and invasive species, resulting in loss of habitat and changes in trophic levels, especially in species composition of fish.
These potential changes will be strongly felt by human societies and feedback to the climate system. Sustainable management of continental margins for the greater good needs to involve all stakeholders from civil society, market and government. A new mode of knowledge production from the collaboration of natural and social scientists should be invoked to address issues arising from the myriad of conflicting interests and competitions in the use of continental margins.
We invited contributions on the ecosystem and biogeochemical dynamics of continental margins, how they may change in the future due to anthropogenic drivers and climate change and how the changes may feedback to the climate system and threaten the livelihood of the large coastal human population. The ultimate goal was to provide sound advice to stakeholders about the changing ecosystem in continental margins and potential adverse effects.
F4 – Environmental changes in Eastern Boundary Upwelling Systems: drivers, mechanisms and implications for the ecosystems – Kay-Christian Emeis; Werner Ekau; Zouhair Lachkar
Upwelling systems are ocean areas where the sub-thermocline ocean exhales nutrients and CO2. Massive phytoplankton productivity is supported by upwelled nutrients and forms the basis for spectacularly rich ecosystems with short trophic paths. Empirical and theoretical evidence showed that these areas have responded to past climate change and are expected to respond to future climate change, since they are uniquely sensitive to global, regional, and local changes in atmospheric circulation patterns. They are also dynamically linked to both large oceanic pools of low pH – low oxygen intermediate waters, as well as local hypoxic conditions on the shelf. Several coastal upwelling systems have experienced dramatic shifts in ecosystem structure and fish catches (so-called ecosystem regime shifts) in the observed past, the reasons for which are not clear.
This session invited contributions that:
- address how nutrient, CO2 and oxygen dynamics in upwelling systems are linked to variability in ocean circulation and ventilation,
- examine potential sensitivities and feedbacks linking this variability to the biological system, and
- investigate the magnitudes and time scales of past, present and likely future variations. The session aims at bringing together researchers from different disciplines studying a broad range of aspects linked to upwelling systems, and covering observational, experimental and modeling studies.
The session aimed at bringing together researchers from different disciplines studying a broad range of aspects linked to upwelling systems, and covering observational, experimental and modelling studies.