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Theme sessions

Theme session 1: Ocean climate and physical environment in the North Atlantic and their linkages to changing marine ecosystem.

Conveners: Agnieszka Beszczynska-Möller,  IOPAN, Polen, Kjell Arne Mork, IMR, Norway, Sam Jones, SAMS, UK


Ocean climate variability in the North Atlantic is dominated by decadal-to-multidecadal fluctuations that have profound regional and global impacts. To understand regional changes on climatic timescales requires knowledge of the processes that take place over much shorter periods of time and space. Within the last decade, a vast amount of new oceanographic data have been collected in the North Atlantic. Together with emerging new technologies for long-term ocean observation, advances in data reanalysis and a rapid growth in capabilities of numerical models have significantly increased our knowledge of physical mechanisms in the ocean and how they drive observed changes in North Atlantic marine ecosystems. Modern oceanographic products, objectively synthestizing information from long-term in situ measurements in combination with remote sensing and numerical simulations, have reached the level of maturity that enables their use for the science-based marine environmental management.

For this session we welcome contributions that describe physical variability in the coastal, shelf and deep ocean around the North Atlantic, the Nordic Seas and adjacent shelf seas at seasonal to multi-decadal time scales, and discuss their governing mechanisms and environmental implications. We encourage studies addressing changes in the physical properties, water column structure, ocean dynamics, and atmospheric forcing observed during the decade 2010-2019, in relation to longer-term variability and their concurrent impacts on biogeochemistry, plankton, fish, mammals and seabirds in the North Atlantic. Submissions focused on new integrated methods for data analysis, modelling approaches, and emerging tools for sustained monitoring of the physical environment are particularly welcome.


Theme session 2: Decadal change and trends in North Atlantic/sub-Arctic plankton and their ecosystems.

Conveners: Eileen Bresnan, MSS, UK, Todd O’Brien, NOAA, USA, Luiz Valdes,  IEO, Spain


Across the North Atlantic, and over the last decade, there have been recognized changes in the plankton community that are already impacting ecosystem production, public health, and industry. In the phytoplankton, new evidence of changing phenology as well as additional impacts on shellfish harvesting activities and human health have emerged. In the zooplankton, the northward shift of cool water species continues on both sides of the Atlantic, affecting the biology and ecology of the fish, birds and marine mammals that depend on them. Finally, changing circulation patterns, water chemistry (e.g., anoxia and ocean acidification), and the introduction of additional pressures (e.g., from microplastics and invasive species) place more strain on already temperature-stressed plankton communities and ecosystems.

In a rapidly changing ocean, consistent repeat sampling (e.g. time series) provides a window into the past, present, and future. As we look forward, how do we integrate new technologies (optical and molecular) into our already long-running “net and bottle” time series. In places where this integration is already happening, what where the challenges, and what did these technologies uncover that surprised you?

This session will focus on summarizing and analysing changes in the plankton community over the last 10 (or more) years, highlighting the impacts these changes have already had on the North Atlantic/sub-Arctic/Baltic Sea ecosystems (and industry and tourism), and predicting how these impacts might change or magnify over the next 10 years.


Theme session 3: Trends and drivers of decadal variability in fish and invertebrates.

Conveners: Kathy Mills, GMRI, USA, Mark Payne DTU AQUA, Denmark, Sigrid Lehuta, IFREMER, France


Fish stocks are dynamic resources that are impacted by climate change, environmental variability, and fishing exploitation. To ensure sustainable management of these resources, it is important to understand how fish and invertebrate species respond to these drivers of variability, and the implications for the broader ecosystem and fisheries. This theme session provides an opportunity to summarise how decadal variability has impacted marine species throughout the North Atlantic over the last decade, and how these impacts can be mitigated over the next decade. Abstracts addressing the following topics are welcome:

  • Past and future changes in species distribution and productivity, their consequences, and associated drivers
  • Trends in life history traits (e.g., growth, maturity) and life cycle events (e.g., recruitment, phenology), and how to disentangle drivers of change (i.e., climate change vs. environmental variability vs. fishing)
  • Fish stock collapses and recoveries and how these impact commercial fisheries (choke species vs. opportunity for new target species)
  • Trends in species composition in North Atlantic ecosystems and their management implications


Theme session 4: Expanding horizons: assessing decadal changes and incorporating Social-Ecological Systems in the North Atlantic

Conveners: : Caroline Cusack, MI, Ireland, Silvana Birchenough, Cefas, UK, Lisa Colburn NOAA, USA


Social and ecological dimensions of marine ecosystems are dynamic, often responding to pressures over time at an unprecedented rates. Natural scientists have concentrated on bio-physical changes through time-series observations, experimental and modelling approaches. Social scientists have focused on the human dimension through assessment of social and cultural responses to changing ecosystems.

These efforts have documented significant evidence of the ways humans have influenced the North Atlantic and are impacted by pressures over time. A transdisciplinary approach is critical to advance societal responses. Social- ecological systems (SES) analysis provides a critical interface between natural and social science assessments of marine systems. The past decade has seen SES emerge into a central role in policy but remains an afterthought in many frameworks and assessments. The dramatic change in North Atlantic ecology and human uses on decadal scales offers the opportunity to define future studies and responses.

To fully engage in policy frameworks, social and ecological scientists will need to provide cogent examples of integrated research that can advance our understanding of human interactions with ecological change in the marine social ecosystem. These examples, including case studies, techniques, methodologies, lessons learned, and feed-back loops will need to inform priorities for the unprecedented challenges that face the North Atlantic. This session seeks to broaden the scope of our current efforts: we invite transformative accounts of the ideas, frameworks, challenges and successes in the integration of social and ecological data to address large-scale temporal and spatial change in the North Atlantic SES.