Physical / Biogeochemical / Biological / Geological / Environmental / Interdisciplinary /

Physical Oceanography  
PHY-01 The Arctic Ocean: Physics, climate & ecosystem
  Arctic Ocean: Physical Processes and their Effects on Climate and the Ecosystem
Peigen Lin (Woods Hole Oceanographic Institution)
Robert S. Pickart (Woods Hole Oceanographic Institution)
G.W.K. Moore (University of Toronto)
  Session Description:

The Arctic Ocean is undergoing dramatic and amplified changes as the global climate continues to warm. Air temperatures have been increasing, which in turn has led to enhanced ocean warming in summer and enhanced cooling in fall. At the same time, more heat is being fluxed from the subarctic into the Arctic, via the Pacific water inflow through Bering Strait and Atlantic water inflow through Fram Strait and the Barents Sea Opening. As a result, sea ice cover and thickness have been declining at an accelerated rate with earlier freeze-up and later melt-back. It is thought that the increased freshwater content in the Arctic could lead to enhanced freshwater export into the Nordic Seas and Labrador Sea, impacting the Atlantic Meridional Overturning Circulation. In conjunction with these changes in the physical drivers, the ecosystem is being dramatically altered. Primary production is increasing, including under-ice blooms, sub-polar species are invading Arctic waters, ocean acidification is becoming more prevalent, and massive harmful algal blooms have been commonly found.

This session aims to understand: (1) Variations and dynamics of physical processes in the Arctic Ocean and their interaction with the subarctic regions in both the Pacific and Atlantic sectors; (2) Climate responses to the declining sea ice, including atmospheric feedbacks; (3) The roles of the physical processes in regulating the Arctic ecosystem and biogeochemistry. 

PHY-02 Atlantic Ocean Variability
  Atlantic Ocean variability in a changing climate
Feili Li (Xiamen University)
Yao Fu (Georgia Institute of Technology)
Marilena Oltmanns (National Oceanography Centre at Southampton)
Sijia Zou (Xiamen University)
  Session Description:

By redistributing a large amount of heat and salt, the Atlantic Ocean significantly impacts regional and global climate over a wide range of time scales. In particular, the subpolar North Atlantic has seen strong variations in ocean heat and freshwater content over the past couple of decades, as well as in the uptake and storage of anthropogenic carbon, which has been attributed to changes in the large-scale Atlantic circulation. However, the mechanisms through which the ocean circulation changes and impacts the climate system and their feedback and predictability remain elusive. This session invites contributions that advance our understanding of Atlantic Ocean variability, the role it plays in the atmosphere–ocean–ice system, and its role in extreme weather events and abrupt climate change. It aims to bring together recent progress in understanding the circulation and climate variability in the Atlantic sector from paleoclimate, historical, and future perspectives. Studies utilizing observational, modeling, and/or theoretical frameworks are all welcome.

PHY-03 Sea level rise: understanding, observing, and modelling
  Sea level rise: understanding, observing, and modelling
Kewei Lyu (Xiamen University)
Xuebin Zhang (CSIRO Oceans and Atmosphere)
Xuhua Cheng (Hohai University)
Jianyu Hu (Xiamen University)
  Session Description:

Sea level rise is a critical climate change issue. Global mean sea level has been rising, mainly due to ocean thermal expansion and melting of land ice. Rising sea level increases destructive risks to the coastal environments from hazards such as storm surge, flooding, and erosion. In addition to the global mean sea level rise, sea level change occurs over a wide range of spatio-temporal scales, driven by both long-term anthropogenic climate change and natural climate variabilities. Regional sea level change displays significant spatial non-uniformity, caused by the redistributions of heat, salt, and mass in the ocean through ocean dynamics as well as changes in Earth’s gravity and rotation and viscoelastic solid-Earth deformation induced by land ice mass changes (known as sea-level fingerprints). Therefore, for regional adaptation and mitigation planning purpose, it’s critical to understand regional sea level change and its coastal impacts, which has been identified as one of seven Grand Challenges by the World Climate Research Programme (WCRP). In this session, we solicits contributions from a broad scope of presentations related to sea level research, e.g., ranging from global studies to regional studies, from observation-based studies to modelling-based studies, from remotely sensed to in-situ observed analyses, from ocean-only modelling to integrated earth system modelling, from mean sea level studies to extreme sea level (e.g., storm surge and waves) studies, with the aim to share new findings in sea level studies, prompt developments for better sea level understanding and projecting, guiding future adaptation and mitigation planning for coastal communities.

PHY-04 Cross-scale interactions: mesoscale and smaller
  Cross-scale interactions in (sub)mesoscale motions, internal waves, surface waves and boundary layer turbulence
Xiaolong Yu (Sun Yat-sen University)
Peng Wang (Sun Yat-sen University)
Peng Zhan (Southern University of Science and Technology)
Jihai Dong (Nanjing University of Information Science and Technology)
  Session Description:

An array of turbulent regimes are realized in the ocean, from millimeter-scale dissipation processes to mesoscale eddies spanning hundreds of kilometers. This turbulence plays critical roles in the Earth system, for example by mediating the energy transfer between large-scale forcing and dissipative scales, by exchanging mass and tracers between the mixed layer and the ocean interior, or by coupling with small-scale motions with larger-scale background dynamics. However, there are many challenges that limit our understanding of these turbulent processes and their impacts on the real ocean. These challenges stem from the vast multitude of turbulent motions in the ocean, from their nonlinear nature which catalyzes interaction between different turbulent regimes, and from the inherent challenges of modeling or observing across this range of scales.

This session invites contributions from observational, modeling, and theoretical studies that shed light on cross-scale interactions and transfers between different regimes (mesoscale eddies, submesoscale flows, internal waves, surface waves, boundary layer turbulence, etc.). We are also interested in studies that place these turbulent processes in a wider context, including the advancement of parameterizations to emulate these processes, the development of novel observational or analytical tools to quantify them, and the assessment of their impacts on the wider ocean and Earth systems at regional and global scales.

Keywords: Mesoscale eddies; Submesoscale flows; Internal and inertial waves; Surface waves; Turbulence; Upper-ocean and mixed layer processes

PHY-05 Southern Ocean heat uptake and transport in a changing climate
  Southern Ocean heat uptake and transport in a changing climate
Fukai Liu (Ocean University of China)
Yiyong Luo (Ocean University of China)
Xichen Li (Institute of Atmospheric Physics)
  Session Description:

The Southern Ocean (SO) that links different ocean basins and connects the surface ocean with the abyss plays a fundamental role in the climate system. In particular, it is generally recognized an effective buffer of the ongoing global warming because the prevailing strong westerly winds draw up cold water from below to absorb a vast amount of anthropogenic heat from the atmosphere. Most of the excessive heat enters the SO at the southern flank of the Atlantic Circumpolar Current through water mass transformation, and is transported northward by mean circulation and deposited into the ocean interior. Yet, because of scarce observations and complex processes that operate but poorly understood including oceanic eddies and ocean-atmosphere-cryosphere interactions, many open questions remain about the underlying mechanisms of heat uptake and transport in the SO in a changing climate.

This session invites submissions that utilize observational and modeling frameworks to advance our understanding of the dynamical processes of the SO, with a particular focus on discerning mean circulation and eddy’s contribution to the strong heat uptake and transport. Topics of interest include, but are not limited to, studies that improve our understanding of large-scale and regional ocean circulation, mesoscale/submesoscale processes, ocean mixing, water mass transformation, air-sea fluxes, and tropical-polar interactions.

PHY-06 Oceanic Internal Waves
  Internal Waves in the Ocean: Generation, Evolution and Implication
Xiaolin Bai (Xiamen University)
Zhenhua Xu (Institute of Oceanology, Chinese Academy of Sciences)
Zhiyu Liu (Xiamen University)
Zhiwu Chen (South China Sea Institute of Oceanography, Chinese Academy of Sciences)
  Session Description:

Internal waves have a wide range of scales but are typically unresolved in climate or global models. With an unprecedented capability of observing and simulating these processes, they are becoming increasingly important to quantify the upscale effect of these processes in order to provide solution to regional or climate issues (e.g., heat uptake, sea level), interdisciplinary issues (e.g., physical-biogeochemical interactions), and sustainability issues (e.g., environmental management). Therefore, our session would like to bring together a broad range of contributions presenting advances in, and approaches to, studying, modelling, monitoring, and forecasting of internal waves in the ocean as well as stratified estuaries and lakes. 

The scope of this session involves all important aspects of internal waves and their implications for ocean mixing and mass transport, such as internal wave generation from various mechanisms, reflection near boundaries, propagation through and interaction with larger-scale flows, wave-induced mean flow, wave-wave interactions in general, wave breaking and its implications for mixing and biogeochemical elements, as well as parameterization of these processes in models not explicitly resolving internal waves. 

This session is intended to bring together experts from all fields of working on related problems. Presentations on theoretical, modelling, experimental, and observational work with regard to all aspects of internal waves are most welcome. 

Marine Biogeochemistry
BGC-01 Mercury biogeochemical cycling in the ocean
  Mercury biogeochemical cycling in the ocean
Yanbin Li (Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China)
Feiyue Wang (Centre for Earth Observation Science, and Department of Environment and Geography, University of Manitoba)
  Session Description:

Mercury (Hg), a potent neurotoxin, is among the most widespread contaminants that are posing potential threat to both humans and wildlife. Mercury in the ocean is of particular interest since humans and wildlife are exposed to Hg mainly by consuming seafood. Understanding and resolving the mercury contamination problem is thus critical for a sustainable and healthy ocean, which needs multidisciplinary studies in this field. With the implementation of the Minamata Convention on Mercury since 2017 to reduce anthropogenic Hg emissions, the level of total mercury in the ocean is expected to decrease with time. However, it remains unknown whether and when a similar reduction will be seen in the risk of Hg to marine ecosystems and human health, mainly due to uncertainties in the system efficiency of transforming inorganic Hg to methylmercury (MeHg), which is the main Hg form that biomagnifies in the food chain and poses risk to human health. This highlights the importance of investigating the biogeochemical cycling of Hg in the ocean. The goals of this session are to highlight recent developments in the understanding of Hg distribution, budget, transport and transformation processes in marginal seas and the open ocean, and to discuss the long-term change of oceanic Hg risk with the implementation of the Minamata Convention in a changing climate. This session will be of great value to attendees who are interested in mercury cycling in the ocean and in aquatic environments in general, as well as in chemical oceanography.

BGC-02 Biological carbon pump
  Towards a more holistic understanding of the biological carbon pump
Yang Xiang (School of Oceanography, University of Washington)
Yuan Shen (State Key Laboratory of Marine Environmental Science, Xiamen University)
Wei-lei Wang (State Key Laboratory of Marine Environmental Science, Xiamen University)
Trang Nguyen (Department of Biological Sciences, University of Southern California)
Anna Belcher (British Antarctic Survey)
  Session Description:

The importance of the ocean’s biological carbon pump (BCP), the process of exporting surface-produced organic matter (OM) into the deep ocean, and its role in alleviating the rising atmospheric carbon dioxide have long been recognized. Recent advances in the observational and modeling approaches have demonstrated multi-faceted export pathways and diverse biogeochemical processes that operate on wide-ranging temporal and spatial timescales, from days to years and from microscale (𝜇m) to mesoscale (km). New ship-based observational instruments (e.g., particle imaging and optics), analytical techniques (e.g., omics, biomarkers, isotopes), and modeling studies yield novel insights into the complex mechanisms of BCP, including the significance of zooplankton and microbial communities in altering sinking OM flux. Meanwhile, autonomous platforms (e.g., gliders, BGC-Argo floats) have been gathering data with unprecedentedly high spatiotemporal resolution. Integrating these fields leads to a more holistic understanding of the BCP. This session welcomes experimental-, field- and modeling-based studies that quantify and/or investigate mechanistic controls on the strength/processes of the BCP. Abstracts focusing on biological, chemical, and physical aspects of the BCP are all encouraged. We aim to identify gaps and challenges and discuss new directions and potential points of collaboration for future BCP research.

BGC-03 Biogeochemistry of DOM
  Processing and transformation of natural dissolved organic matter across ecosystems
Hongmei Chen (Xiamen University)
Ding He (The Hong Kong University of Science and Technology)
Zhanfei Liu (The University of Texas at Austin)
Hongyan Bao (Xiamen University)
Yuan Shen (Xiamen University)
  Session Description:

Natural dissolved organic matter (DOM) serves as a mobile and active component involved in diverse aspects of biogeochemical processes in ecosystems, influencing the sustainability and health of aquatic environment.

DOM contains both recalcitrant and reactive characteristics being revealed in the last few decades, in the background of rapid application of an array of analytical techniques for investigation of their transformation and processing. This session aims to bring together research on the distribution, transport, transformation, and fate of DOM along the continuum from inland waters to rivers and to coastal and open ocean ecosystems. We invite contributions from a broad range of elemental biogeochemistry (carbon, nitrogen, sulfur, phosphorus, and halogen elements) that cut across ecosystem boundaries on diverse spatiotemporal scales. We welcome topics regarding biotic and abiotic drivers that shape the molecular composition of natural DOM and its linkage with ambient microbial communities. Studies showing the observed characteristics and transformation of natural DOM, examining the underlying mechanisms and their responses to changing climate, and discussing photochemical and microbial processes as well as the formation of recalcitrant DOM are all warmly welcome.

BGC-05 Coastal biogeochemical processes in a climatically sensitive ocean
  Coastal biogeochemical processes in a climatically sensitive ocean
Ruifang C. Xie (Shanghai Jiao Tong University)
Mark J. Hopwood (Southern University of Science and Technology)
  Session Description:

Coastal systems play a central role in modulating carbon, nutrient and trace element transfer between the terrestrial, cryosphere and marine domains. Shelf seas host the world’s most productive fisheries and efficient carbon sinks, but are highly susceptible to anthropogenic impacts and climatic forcing. How continued global warming, ocean deoxygenation, ocean acidification, and enhanced coastal erosion may influence the global biological carbon pump remains a question at the frontier of marine science. This session seeks to bring together geochemical, biological and physical scientists working on coastal systems to gain an integrated view of coastal biogeochemical processes over the geologic past, present and future. We thus invite submission of field, experimental and modelling studies focusing on carbon, major nutrients, trace elements and their isotopes, or physical drivers of productivity and exchange in these systems. We encourage submission focusing on (1) the relationship between land-to-sea flux of major and trace nutrients, and coastal productivity, (2) assessment of shelf processes governing the distribution, isotopic composition, and speciation of water column macro- (e.g., N, P, S, Si) and micronutrients (e.g., Fe, Zn, Cd), and (3) removal/supply processes of inorganic nutrients and organic matter across the land-ocean and water-shelf sediment interfaces. Studies that combine multiple methodological approaches to understand dynamic shelf regions are especially welcomed.

BGC-06\INT-04 Ocean Health and Biological Carbon Pump with BGC-Argo
  Monitoring Ocean Health and Studying the Biological Carbon Pump with the Global Biogeochemical-Argo (BGC-Argo) Array
Xiaogang Xing (Second Institute of Oceanography)
Andrea J. Fassbender (NOAA Pacific Marine Environmental Laboratory)
Christina Schallenberg (Oceans and Atmosphere, CSIRO)
Emanuele Organelli (Institute of Marine Science, Italian National Research Council)
  Session Description:

Anthropogenic activities are rapidly changing the oceans, causing myriad issues for ocean health, including: ocean warming, acidification, eutrophication, pollution, deoxygenation, nutrient flux reduction, vital habitat destruction, declining fishery resources and an increasing number of endangered marine species. Simultaneously, the natural, biological carbon pump plays a vital role in sequestering carbon from the atmosphere to the deep ocean, exerting an important control on global climate. Understanding how anthropogenic factors may influence the efficiency of the biological carbon pump and how this could in turn alter the trajectory of global warming and ocean health are key research priorities. Comprehensive monitoring of ocean health and the biological carbon pump will require broad spatial coverage, high-frequency and vertical-resolution sampling, as well as multi-disciplinary measurements; something difficult to achieve with traditional observing systems. With the fast development of profiling float and sensor technology, the international BGC-Argo program is currently building a global, multidisciplinary ocean-observing network of autonomous Argo floats equipped with an extensive range of biogeochemical sensors. This global array is quickly filling the observing gaps of traditional platforms, providing revolutionary insights into ocean biogeochemistry and marine ecosystems, and thus greatly improving our understanding of ocean health and the biological carbon pump. Such new scientific understanding is also improving model forecasts and productions of ocean conditions and ecosystem health. This session will focus on advances in our understanding of ocean health and the biological carbon pump through observing and modeling studies that leverage the BGC Argo array.

BGC-07 Hypoxia and deoxygenation
  Drivers and consequences of marine dissolved oxygen depletion: from estuaries to the open ocean.
Zhuoyi Zhu (Shanghai Jiao Tong University)
Yangyang Zhao (Xiamen University)
Guodong Song (Ocean University of China)
Liuqian Yu (The Hong Kong University of Science and Technology)
Qicheng Meng (Second Institute of Oceanography MNR)
Ding He (The Hong Kong University of Science and Technology)
  Session Description:

Dissolved oxygen is declining in both the open ocean and coastal waters. The increasing emergence of estuarine and coastal hypoxic sites across the globe are mostly attributed to anthropogenic activities, while the oxygen loss of the open ocean is not only due to warming-induced decrease of oxygen solubility in seawater, but also changes in ocean circulation and biological metabolism. This oxygen decline in oceans is also predicted to continue and even accelerate under human activities and global climate change. Our in-depth understanding of marine dissolved oxygen depletion, in terms of its temporal variability and drivers for steady-state and dynamic process at basin- and regional scales and its biogeochemical, ecological, and eventual climatic consequences, is the base of scientific policy and solutions to mitigate the oxygen loss for the sustainability and health of the ocean. Under this background, this session welcomes all studies of oxygen depletion from varied disciplines that emphasize physical, chemical, biological, ecological, policy or solution aspects, covering both steady-state (oxygen deficiency) and dynamic process (deoxygenation) based on observations and model simulations. The encouraged topics include, but not limited to: 1) resolving the spatial and temporal variability of oxygen changes; 2) diagnosing the physical and biogeochemical drivers of oxygen declines; 3) examining the response and potential feedback of ocean biogeochemical processes and ecosystem dynamics to marine oxygen depletion; 4) investigating the interplay of ocean deoxygenation and other stressors (e.g., warming, acidification, and changes in ocean productivity); 5) future projection under different carbon emission scenarios, and approach to mitigation. This section welcomes studies based on observational, experimental, conceptual, or modelling approaches, particularly those using multidisciplinary observational platforms (e.g., repeated shipboard hydrography, moored buoy array, Argo profiles and time-series stations) and new methods leveraging machine learning and other advanced techniques.

BGC-08 Ocean Negative Carbon Emission and Sustainable Development
  Ocean Negative Carbon Emission and Sustainable Development
Peng Xiu (South China Sea Institute of Oceanology)
Yao Zhang (Xiamen University)
Mark Wells (University of Maine)
Andrew Lenton (Commonwealth Scientific and Industrial Research Organisation)
  Session Description:

Atmospheric CO2 concentration has reached historically unprecedented levels due to anthropogenic CO2 emissions, which drives global warming and climate change. To meet the goal of the Paris Agreement to limit global warming to 1.5°C by the end of this century and the 2030 agenda for sustainable development, simply reducing the levels of human emissions may not be enough. Ocean negative carbon emission is considered to be a promising approach to lower atmospheric CO2 level, in conjunction with reducing emissions. The ocean has a large capacity to sequester carbon and has absorbed approximately 25% of the anthropogenic CO2 since the beginning of the industrial revolution. It may be possible to enhance that capacity and/or accelerate the rate through implementation of different carbon sequestration approaches, which has the potential to contribute to carbon neutrality if the mechanisms and processes involved are properly understood and risks associated with marine environment and ecosystem can be managed.

Four major ocean carbon pumps have been recognized for the ocean to sequester atmospheric CO2, including the solubility pump, the organic carbon pump (BCP), the carbonate pump (CCP), and the microbial carbon pump (MCP). Based on these mechanisms, several ocean-based carbon sequestration methods have been explored, such as iron fertilization (, MCP-BCP-CCP coupling (, conservation and restoration of coastal and marine ecosystems (, ocean alkalinity enhancement (, seaweed cultivation, and artificial upwelling and downwelling. Across all approaches, however, knowledge gaps remain in determining carbon sequestration efficacy, scaling, and durability, as well as environmental and ecosystem impacts and associated costs. Evaluation in terms of carbon sequestration potential, research and development needs, and technological readiness vary widely at this time. To address the gap in understanding and the need for further exploring various ocean-based carbon sequestration methods, this session welcomes contributions from studies that examine topics on advances and developments related to ocean negative carbon emission approaches for the mitigation of climate change and the sustainable development of marine ecosystems from lab investigations, numerical modelling, to field experiments, as well as technical feasibility and cost effectiveness. Research that address scientific knowledge base, efficacy and scale, monitoring and verification, marine ecosystem impacts, risks and co-benefits, viability and barriers, governance and social dimensions are encouraged for submission.

BGC-09 Biogeochemistry in Subtropical Oceans
  Understanding the upper ocean biogeochemistry in the oligotrophic subtropical gyres
Kuanbo Zhou (Xiamen University)
Tom Browning (GEOMAR Helmholtz Centre for Ocean Research)
Qian Liu (Ocean university of China)
  Session Description:

Subtropical gyres account for a vast surface area (~30%) of the oceans and play an important role in the Earth’s climate system. Due to their remoteness from continents and persistent stratification, nutrients are exhausted in the upper ocean, which results in low biological production and phytoplankton biomass levels. Although great effort has been made during the last three decades through the implementation of the time series biogeochemical stations, e.g., the Hawaii Ocean Time-series (HOT), our knowledge of the upper ocean biogeochemistry of the oligotrophic gyres is incomplete and uncertainty regarding their contribution to the ocean carbon cycle (especially carbon export) is remains large. This session sets out to focus on progress that has been made recently on the biogeochemistry of the subtropical gyres, including macro-and micro-nutrient inventories, sources and dynamics, primary production and nitrogen fixation, microbial community structure, through to export of carbon into the deeper ocean. New results from field programs, remote sensing studies and numerical modelling are particularly welcomed. We aim to build up a systemic level of the latest understanding of the gyres’ biogeochemistry as well as contributing to recommendations for future research in these systems.          

Biological Oceanography
BIO-01 Harmful Algal Blooms
  Harmful algal blooms under changing climate: mechanisms, monitoring, and mitigation for a sustainable, safe and healthy ocean
Po Teen Lim (University of Malaya)
DaZhi Wang (Xiamen University)
HaiFeng Gu (Third Institute of Oceanography, MNR, Xiamen)
YingZhong Tang (Institute of Oceanology, Chinese Academy of Science (IO-CAS))
Jianping Li (Shenzhen Institute of Advanced Technology Chinese Academy of Sciences)
  Session Description:

Harmful Algal Blooms (HABs) occur due to the proliferation of harmful microalgae in the aquatic ecosystems, resulting in deleterious effects on the coastal communities. This included the contamination of commercially important shellfish, massive mortality of farmed or wild finfish, and damage to the value of the marine ecosystem. The increasing impacts of HABs on the socio-economy and public health are tremendous, affecting regionally and globally, partly because of the emergence of new HAB events in areas with no prior record, also, involving novel toxic species. Owing to the increasing HAB occurrence and intensity, sustainable development of the rapidly growing aquaculture industries in many coastal countries has been hindered by HAB-related fish kill and shellfish toxicity events.  In this proposed session, we will focus on several aspects of HABs: 1) dynamics of HABs, from molecular to ecological levels; 2) physiological and molecular responses of HAB species to biotic and abiotic drivers; 3) monitoring and forecasting of HABs using novel tools and instrumentation for early detection and warning; 4) development and application of techniques to mitigate and minimize the impact of HABs. Trends of HAB events (species, occurrence, and frequency) under the changing climate will also be a topic of interest in this session. Presentations related to the collaborative effort to strengthen regional and international collaborations and joint research efforts in addressing the expanding HAB issues in the region are also welcomed.

BIO-02 Key changes in ocean variability and the effects of climate change
  Key changes in ocean variability and the effects of climate change
Yuntao Zhou (School of Oceanography, Shanghai Jiao Tong University)
Lijing Cheng (Institute of Atmospheric Physics, Chinese Academy of Sciences)
Linlin Zhang (Institute of Oceanology, Chinese Academy of Sciences)
Long Cao (School of Earth Sciences, Zhejiang University)
  Session Description:

Ocean have responded to climate change in many different ways, including sea level rise, sea temperature/salinity change, ocean acidification, and ocean deoxygenation, which profoundly affect ocean circulation, productivity, nutrient cycling etc. These changes together could further threaten the biota in ocean and the health of marine system. Thus, it is critical to develop an improved understanding of the mechanisms driving long-term trends and variability in these key ocean elements. In addition, we need to document and predict how these ocean elements will change in the future under climate change, such that society can make informed decisions and understand costs and benefits trade-offs for mitigation, tourisms, and fisheries. How to reasonably use observations and modelling results to accurately reflect ocean changes is still a grand challenge. Improved observation coverage and quality, data processing techniques, and numerical modelling of the changes in ocean are critically needed. In addition, unravelling the causes and consequences of these changes is also a further challenge. The objective of this session is to bring together the efforts in observing and understanding historical and/or future changes in ocean under climate change, to explore the mechanisms behind these changes, and to examine the effects of these changes on ocean plants and animals. This session aims to discuss how we can achieve more reliable and accurate observational datasets and projection tools.

BIO-03 Diversity of marine host-associated microbiomes
  Diversity, dynamics and function of host-associated microbiomes in marine organisms
Yunyun Zhuang (Ocean University of China)
Senjie Lin (University of Connecticut)
Caiwen Li (Institute of Oceanology, Chinese Academy of Sciences)
Jianwei Chen (BGI-Qingdao, China)
  Session Description:

Marine organisms provide special microhabitats harboring highly diverse microbes such as bacteria, archaea, fungi, algae, and protozoans. Remarkably, hidden genetic diversity of marine symbiotic microbes has been revealed with molecular approach. Host-symbiont relationships have been widely observed in the ocean from deep-ocean environment to coral reef ecosystem, which falls into three categories including commensalism, parasitism and mutualism. This relationship is dynamic that could be transient or persistent and shaped by both microhabitats within host organism and physiochemical environments. The consortia of host-associated microbiome, rather than individual symbiont independently, play vital roles in the fitness, adaptation and evolution of host organisms. Such effects also extend to community and ecosystem levels in terms of biodiversity, food web structure and biogeochemical cycling that underpin the health of marine ecosystems. Thus, elucidating the diversity, dynamics and function of host-associated microbiome can provide insights into the shaper of biodiversity, the driver of structure and function of marine ecosystem and have important implication in conservation strategies.

Despite an increasing research interest on host-associated microbes, most of the studies focused on certain groups such as pathogen, epibiont or gut microbes. Little is known about the succession of complex multi-assemblage microbiome associated with host, and how the microhabitats within host and physiochemical environment jointly shape the symbiotic community remain elusive. Such situation calls for uniting ecological and molecular approach to characterize the diversity and function of host-associated microbiome with different forms of symbiosis, particularly over variety of temporal and spatial scales from an eco-evolutionary perspective.

This session will provide venue for exchanging ideas and findings on microbiome associated with diverse marine taxonomic groups from protist, seaweed, invertebrate, fish to mammal. We welcome presentations that explore the following themes or other closely related topics:

  • Diversity and assembly mechanism of marine host-associated microbiome
  • Spatial and temporal distribution pattern of host-associated microbiome and its regulating factors.
  • Ecological functions of marine host-associated microbiome with respect to host (fitness, adaptation and evolution) , community and ecosystem (biodiversity, elementary cycling)
  • Omics and bioinformatics methods tackling challenges in sequencing, assembly and annotation of metagenomes of host-associated microbiome.
BIO-04\INT-05 In situ Imaging of Plankton and Particles
  In situ Imaging of Plankton and Particles: Needs, Methods and Trends.
Jianping Li (Shenzhen Institute of Advanced Technology Chinese Academy of Sciences)
Klas Ove Moller (Institute of Carbon Cycles Helmholtz-Zentrum Hereon)
  Session Description:

Planktonic organisms and marine snow serve as the productive base of aquatic ecosystems, play a major role in oceanic food webs, have an important impact on the ocean’s carbon cycle and sometimes produce harmful algal blooms that can threaten ecosystem and human health. Therefore, it is necessary to understand the processes that control the spatial and temporal distribution as well as the abundance of these organisms. Over the past few decades, numerous in situ imaging methods have been developed to observe planktonic organisms and marine snow. These methods are typically used to detect, measure, and enumerate organisms and particles. The increasing use of imaging systems has permitted description of planktonic communities with unprecedented levels of spatial and temporal resolution, together with their linkages with biogeochemical cycles and environmental constraints.

Recent developments in optics, electronic chips, artificial intelligence, and new material technologies is now further increasing the opportunities to improve future underwater imaging systems, allowing to include smaller, lighter, smarter and more energy efficient devices into various observation platforms such as AUVs, Argo floats, moorings, and subsea ocean networks. However, these developments will bring new challenges in the coming years, such as rapidly producing billions of new images, necessary quality checks, as well as classification, harmonization, and intercalibration of instruments & real-time outputs, to name a few.

This session will focus on both technical developments and their applications of in situ optical imaging technologies for high-resolution observations of marine plankton and particles from small- to global scales. Presentations on new emerging technologies should extend beyond pure technological challenges, in order to provide insights into ecological and biogeochemical processes in various aquatic ecosystems. Successful applications, evaluation of advantages and shortcomings, and future needs for imaging methodology are welcome as well as recent developments in image analysis methodology and data handling. The session aims for closer communications between scientists and engineers to understand the needs, challenges, and possibilities of in situ optical imaging observation technology for studying the oceans and seas for their health and sustainability.

BIO-05\INT-06 Primary production estimation
  Remote sensing of oceanic primary production
Zhongping Lee (Xiamen University)
Joaquim Goes (Columbia University)
Robert Brewin (University of Exeter)
  Session Description:

Primary Production (PP) drives the oceans biological pump, impacting the sequestering of atmospheric CO2. Due to the vast size of the global oceans, the only viable means to monitor the spatial and temporal variations of PP is via remote sensing by satellites. Over the past few decades, a wide range of algorithms have been developed for the estimation of PP that use inputs from satellite measurements of ocean color. However, discrepancies with in-situ measurements, and uncertainties in model inputs, parameters, and outputs, still exist. We thus take this opportunity to invite the community to share recent progress on this topic and to discuss gaps/limitations that need to be addressed in order to reduce uncertainties of remotely sensed PP in the coming years. Abstracts covering field measurements, remote sensing algorithms, satellite products related to primary production, and comparisons of satellite products with ecosystem models, are all welcome.

BIO-06\INT-07 Ecological connectivity-past, present and future.
  Ecological connectivity in the ocean-past, present and future. Environmental influences, and implications for biodiversity and conservation.
Annalisa Bracco (Georgia Tech)
Joseph Montoya (Georgia Tech)
  Session Description:

Anthropogenic stressors, from climate change to overfishing, threaten ocean biodiversity and ecosystem functioning. Even the most optimistic climate scenarios predict a strong reduction of ocean biodiversity by 2100. Understanding how ecosystem connectivity is shaped by climate change and linked to biodiversity and resilience is key to improve chances to establish sustainable management practices. For example, connectivity is pivotal to designating effective marine protected areas.

In this session we seek studies that evaluate ocean connectivity at multiple scales and times, from regional to global scales, from days to decades, and with any kind of approach, from field work to modeling or machine learning methods. The objective is to summarize current understanding, help establishing best practices to evaluate connectivity, connectivity changes and linkages between connectivity and biodiversity, and identify ways to monitor marine ecosystems, increase their resilience and protect biodiversity throught multidisciplinary approaches.

  Data Science for Marine Ecosystem Studies (DS4MES)
Wenfang Lu (Sun Yat-Sen University)
Wupeng Xiao (Xiamen University)
Wei-Lei Wang (Xiamen University)
  Session Description:

Recent decades have witnessed the enhancement of high-performance computing capabilities, the explosive growth in oceanographic data owing to autonomous sampling methods (e.g., FlowCam, CPR, Bio-Argo, and biogeochemical gliders), and advances in remote sensing techniques. Collectively, the massive volume of marine observations has enabled artificial intelligence (AI) to revolutionize the field of marine sciences. The growing applications of data science from small-scale (molecular and genomic) to large-scale (basin to global) enhance the predictability and produce exciting and profound findings. However, interpreting and extracting useful information from these data is still a great challenge, and a new data-driven paradigm is urgently needed. The session will discuss a variety of topics, including but not limited to AI model developments, case studies with AUV data, remote sensing retrieval, applications on data reconstruction/feature recognition, and fusing data-driven methods with existing ecosystem modeling approaches etc. Any contributions emphasizing the usage of artificial intelligence and big data are welcome. Our ultimate goal is to advance data science application in marine ecosystem study and expand the frontier marine sciences. 

BIO-08 Tracking anthropogenic changes using benthic fauna
  Tracking anthropogenic changes in global oceans- the importance of benthic fauna
Punyasloke Bhadury (Indian Institute of Science Education and Research Kolkata)
Xiaoshou Liu (Ocean University of China)
  Session Description:

Global oceans influence the climate of our earth and sustain socio-economics of millions of people on a daily basis. From land-ocean boundary to deep-sea, organismal biodiversity is key to sustaining ocean ecosystems. Benthic macro- and meiofauna that dominate sedimentary environments from coast to deep abyss play important roles including trophic interactions, microbial facilitation as well as cycling of carbon and nitrogen. Increasingly, oceans globally are facing changes due to increasing anthropogenic activities including from overfishing, exploitation of marine bioresources, release of pollutants such as forms of nitrogen or pesticides as well as from litter including microplastics. These are affecting the health of our oceans at unprecedented scales like never before. In addition, increasing natural disturbances (e.g. cyclones, storm surge, changes in monsoonal patterns) are also affecting ocean ecosystems more frequently. Benthic faunal communities are more sensitive, respond to natural and anthropogenic disturbances in terms of biological traits as well as some species are sensitive to disturbances. Some benthic faunal groups are resilient and disturbance adapted and thus can be excellent proxy to track changes in modern oceans. In this session we welcome submissions looking at the use of benthic fauna to track natural and anthropogenic changes from coastal ocean to deep-sea sedimentary environments. Studies that look at the ecosystem level responses to disturbances using benthic fauna as proxy are particularly welcome. We particularly welcome submissions from early-career researchers working in the broad area of benthic ecology and linking to understanding of ocean health. Submissions pertaining to emerging areas of benthic faunal research that integrate new tools and approaches such as next-generation sequencing or artificial intelligence including neural network models to address the health of modern oceans are also welcome as part of this truly interdisciplinary session.

Geological Oceanography
GEO-01 Present and past ocean-atmosphere-climate interactions
  Modern and past processes of ocean-atmosphere-climate interactions in the low-latitude western Pacific and Indian Ocean
Stephan Steinke (Xiamen University)
Mahyar Mohtadi (University of Bremen)
Jeroen Groeneveld (Taiwan University)
  Session Description:

The low-latitude western equatorial Pacific and Indian Ocean are affected by numerous globally significant ocean-atmosphere phenomena. Those comprise the Walker and Hadley circulations, the El Niño-Southern Oscillation, the Indian Ocean Dipole Mode and the monsoon systems. In addition, the Indonesian Throughflow (ITF) which is exchanging water masses between the tropical Pacific and the Indian Ocean is influenced by and modulates climate in the Indo-Pacific region. It also conveys heat and salt to the Indian Ocean Gateway, which via Agulhas Leakage, influences overturning circulation strength in the North Atlantic and hence global climate. In this context, it is highly relevant to better understand the influence of external forcing and internal climate variability in order to distinguish natural from human-induced changes on the global climate system. Modern observations and the examination of climate and oceanographic variability in this region and comparison with other regional records would help to comprehend the role of Indo-Pacific-driven low-latitude processes on the global environmental change on a range of timescales throughout the Cenozoic. It is the intention of this session to bring together studies on modern and past oceanographic and climatic dynamics of the tropical western Pacific and Indian Ocean as deduced from modern observations, speleothem and coral archives covering the last centuries, millennia, and marine sedimentary archives spanning the Cenozoic.

GEO-03\INT-10 The geochemical and biological study of corals
  The geochemical and biological study of corals
Zhengrong Wang (The City college of New York)
Gangjian Wei (Guangzhou Institute of Geochemistry, Chinese Academy of Sciences)
Senjie Lin (University of Connecticut)
Tiantian Tang (Xiamen University)
  Session Description:

Corals are amazing marine invertebrates that are foci of tremendous amount of researches over several decades. Corals build up reefs that support shallow water ecosystem. They are one of the major calcifiers in the modern ocean that sequester CO2 from Earth’s atmosphere. They are sensitive to environmental stresses (e.g. sea-surface temperature and pH of seawater) and their skeletons faithfully record ample environmental and biological information in modern and paleo-oceans. In this session, we welcome, but not limit to, the submission of researches focusing on 1) describing and characterizing the physiology and biology of corals, as well as the bio-mineralization processes, particularly using advanced biological and chemical techniques; 2) field and lab scale observations of coral ecology and the response of corals to extreme climate stress; 3) applying geochemical proxies documented in coral skeletons to understanding modern and paleo-climates over the world; and 4) advancing our understanding of the origin of the ‘vital effects’ (or biological effect) in coral skeletons.

GEO-04 Millennial to orbital oceanic carbon cycle
  Millennial to orbital oceanic carbon cycle in the Quaternary: processes and mechanisms
Tianyu Chen (Nanjing University)
Enqing Huang (Tongji University)
  Session Description:

The ocean plays a dominant role in the variability of atmosphere CO2 concentration on (sub)millennial to orbital time scales in the Quaternary. However, the processes and mechanisms of carbon exchange between the ocean and atmosphere are still poorly constrained during the Quaternary glacial-interglacial cycles and millennial climate events. In general, air-sea CO2 exchange depends on the ocean’s physical states such as temperature, circulation and ventilation, as well as biological processes that affect the carbon chemistry of seawater. This session welcomes proxies and modelling studies on both physical and biological studies of past oceans that related to carbon cycle in the Quaternary. The topics include but are not limited to changes in carbon chemistry (pH, carbonate ion, alkalinity), biological pump, nutrient utilization, as well as circulation and ventilation of the global oceans in the Quaternary. Together, this session hopes to bring the research frontiers of Quaternary oceanic carbon cycle to the XMAS audience, and builds up potential collaborative studies toward a better understanding of carbon cycle in the Quaternary oceans.

Marine Environmental Sciences
ENV-01 Halogens in the marine environment
  Halogens in the marine environment
Gui-Peng Yang (Ocean University of China)
Yee Jun Tham (Sun Yat-sen University)
Shanshan Wang (Fudan University)
  Session Description:

Halogens, including chlorine (Cl), bromine (Br) and iodine (I), are important elements in the ocean. The marine biological activities and air-sea interaction processes in the ocean provide a large source of organic and inorganic halogens to the atmosphere, which can have significant influence on the cycling of sulfur, air quality, and climate change. Recent findings show that active halogen from oceanic emission has been increasing over the past decades due to global warming, and the halogen chemistry can be further enhanced in regions with influence of human activities (i.e., coastal pollutions, shipping emissions, etc.). Therefore, better understanding of the halogens transformation processes and mechanisms in the ocean and marine atmosphere of a changing world is a key to evaluate their impacts on environment and climate. This session will present and discuss recent new findings on all aspects of halogens and their impacts in the marine environment, including: (1) development of halogens measurement techniques; (2) field observations and satellite studies of halogens in the ocean and marine atmosphere; (3) laboratory experiments and analysis on halogens chemistry; and (4) modelling research of halogen processes and impacts (local, regional, and global scales).

ENV-03 Marine Microplastic
  Marine Microplastic: Novel Methods, Transportation Processes, and Ecological Effects.
Minggang CAI (Xiamen University)
Xiangrong XU (South China Sea Institute of Oceanology Chinese Academy of Sciences, Guangzhou)
Xinhong Wang (Xiamen University)
Peter O. Zavialov (Shirshov Institute of Oceanology, Russian Academy of Sciences)
  Session Description:

In recent years, microplastics have become a major global environmental issue and have attracted worldwide attention due to their ubiquitous presence and potential threats to the ecosystem and human health. They can transport through riverine systems and eventually reach the ocean, even the polar regions. In the past years, much efforts have been paid on microplastic occurrence, mobility, bioaccumulation, and toxicity. However, it is still challenging to develop the andvanced analytical methods and technologies, understand well their fate and ecological risks, and regulate the management of microplastics. State-of-the-art information is urgently needed to i) improve and develop advanced sampling and monitoring methods and techniques; ii) explore source-and-sink processes; iii) evaluate the ecotoxicity; and iv) conduct efficient management of plastic pollution. This session welcomes contributions focused on various aspects of marine microplastics, but not limited to:

1) Novel sampling and monitoring methodologies of marine microplstics.

2) Transport, mixing, and fate of microplastics on their way from land to the ocean, including polar regions.

3) The interaction of microplastics with organic and inorganic pollutants and/or microorganisms.

4) Trophic transfer of microplastics through marine food webs and ecological impacts on marine organisms.

5) Recycling and regulation management for plastics from local to regional and international scales.

Marine Interdisciplinary Sciences
INT-01 SOLAS: Air-Sea interaction
  Surface Ocean and Lower Atmosphere Study: Air-Sea interaction and its climatic and environmental impacts
Guiling Zhang (Ocean University of China)
Bingbing Wang (Xiamen University)
Lin Du (Shandong University)
Zhijun Wu (Peking University)
  Session Description:

The coupled domain of the surface ocean and lower atmosphere is a complex, highly dynamic component of the Earth system. Air-sea exchanges of radiatively active materials and energy exert a major impact on global biogeochemistry and climate. This session will provide opportunities for the scientific community to exchange new ideas and discuss the latest achievements in our understanding of the key biogeochemical-physical interactions and feedbacks between the ocean and the atmosphere, and of how this coupled system affects and is affected by climate and environmental change. This session invites submissions that discuss: (1) Greenhouse gases and the oceans; (2) Air-sea interface and fluxes of mass and energy; (3) Atmospheric deposition and ocean biogeochemistry; (4) Interconnections between aerosols, clouds, and marine ecosystems; (5) Ocean biogeochemical control on atmospheric chemistry. In this session, the marine emissions, atmospheric deposition, chemical transformations of gases and particles, the role of aerosol particles in cloud formation, interactions between anthropogenic pollution with marine emissions, feedbacks from ocean ecosystems and to climate are of particular interest. One aim of the session is to foster collaboration between researchers pursuing fundamental process modeling and performing laboratory experiments and field observations, leading to significant improvements in understanding the key components of the surface ocean and lower atmosphere, thus to understand Earth’s complex climate system.

INT-02 Marine Nitrogen Cycle
  New understanding of marine nitrogen cycle: from microbes to the global ocean
Yue Zheng (Xiamen University)
Xianhui Wan (Princeton University)
Qin Wei (University of Oklahoma)
Yao Zhang (Xiamen University)
  Session Description:

The global ocean is the largest reservoir of reactive nitrogen on Earth. Nitrogen is an important limiting nutrient that exerts significant control on ocean productivity, and the emission of atmospherically active trace gases nitric oxide and nitrous oxide from the oceans have profound impacts on ozone depletion and global warming associated climate change. Thus, as an essential element, nitrogen provides foundation to the function and stability of various marine ecosystems. The marine nitrogen cycle is driven and connected by complex microbial transformation processes, including nitrogen fixation, assimilation, nitrification, anammox, DNRA, and denitrification. Marine nitrogen-transforming microorganisms display extensive phylogenetic diversity and metabolic versatility and have evolved to efficiently access and use every form of nitrogen that spans a wide range of redox states, either for energy production or for biosynthesis. Recent advances in marine nitrogen cycle have come from diverse research fields, including novel physiology and metabolism, new molecular tools, enhanced isotopic labeling techniques, and global biogeochemical modeling. These emerging research directions are already contributing to urgent efforts to address the primary challenge facing marine scientists: the unprecedented onslaught of anthropogenic environmental change on the microbial nitrogen cycle. Ongoing ocean warming, acidification, deoxygenation, and seawater stratification have major effects on the microbial nitrogen cycle. In turn, the responses of marine nitrogen-transforming microbes to anthropogenic perturbation and global climate change will feed back to the cycle of major nutrients, micronutrients, and greenhouse gases.

In this session, we will focus on the wealth of new marine nitrogen cycle research spanning from molecular levels to global biogeochemical scales. We invite contributions that use diverse laboratory, field study, and modeling approaches to study dynamic marine nitrogen transformation processes in a vast range of environments from productive estuaries to oligotrophic pelagic waters, and from the sunlit ocean to the abyssal deep sea and sediments. This session aims for closer communications between marine scientists with different academic backgrounds for studying the marine nitrogen cycle.

INT-11 UN Decade of Ocean Science
  Endorsed or Planned Actions of the UN Decade of Ocean Science for Sustainable Development in Asia and Beyond
Minhan Dai (State Key Laboratory of Marine Environmental Science, Xiamen University)
Fangli Qiao (First Institute of Oceanography, Ministry of Natural Resources)
Kenneth M. Y. Leung (State Key Laboratory of Marine Pollution, City University of Hong Kong)
Xiuzhen Li (State Key Laboratory of Estuarine and Coastal Research, East China Normal University)
Ya-Wei Luo (State Key Laboratory of Marine Environmental Science, Xiamen University)
Nengwang Chen (State Key Laboratory of Marine Environmental Science, Xiamen University)
  Session Description:

The United Nations launched the Decade of Ocean Science for Sustainable Development (“Ocean Decade”) in January 2021, aiming to achieve the ocean we want by 2030. Visioning “the science we need for the ocean we want”, the mission of the Ocean Decade is to transform ocean science to solutions for sustainable development and to connect people and our ocean. In line with the main theme of XMAS-VI, the Ocean Decade provides a common framework to ensure that ocean science can fully support UN member states to achieve the 2030 Agenda for Sustainable Development. It is a ‘once in a lifetime’ opportunity to create a new foundation across the science-policy interface to strengthen the management of our oceans and coasts for the benefit of humanity. A total of 551 actions were endorsed by the Ocean Decade by June 2022. Specifically, Asian countries and intergovernmental organizations (IGOs) have actively participated the Ocean Decade and have had a number of endorsed actions.

As one of the largest international conferences in the field of marine sciences in Asia, XMAS-V organized a Special Forum on the Ocean Decade to increase the overall understanding of the Decade and promote actions. To keep up with the latest advancements and enlighten future prospects, this Ocean Decade Session in XMAS-VI welcomes the endorsed/planned Ocean Decade programmes or projects from Asia and other regions to demonstrate their actions and progress and to exchange ideas for initiating new cooperation under UN Ocean Decade. This session will strengthen the communications and cooperation among the Ocean Decade actions in Asia and beyond, jointly promoting the healthy and sustainable development of the oceans and coastal zones.

INT-12 General Poster Session
  General Marine Environmental Science
Zhimian Cao (Xiamen University)
Feili Li (Xiamen University)
Xing Jian (Xiamen University)
Xin Liu (Xiamen University)
Xudong Zhu (Xiamen University)
  Session Description:

Marine environmental science is multidisciplinary by nature and thus requires cooperative interactions of researchers from different disciplines. For contemporary research areas in marine environmental science, e.g., global change related issues, it is particularly challenging in need of concentrated and inspiring multidisciplinary efforts. This session aims to bring together researchers and engineers from different disciplines (physicists, biogeochemists, geologists, environmentalists, biologists, modelers, etc.) to provide a platform for communicating on new understanding of the ocean environment in the context of global change. This session covers topics of marine environmental science not addressed by special sessions of XMAS-IV and is an ideal avenue to present multidisciplinary and cross-disciplinary research activities.