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Theme session

Published 06.10.2022 - Updated 06.10.2022

Theme session 1: Processes underpinning production in Arctic and Sub-Arctic marine systems undergoing climate change 

Conveners: Hannah Murphy (Fisheries and Oceans Canada) and TBA

Several oceanographic and ecological (top-down, and bottom-up) processes determine productivity regimes in marine ecosystems. Recent changes in climate conditions (e.g., temperature increase and reduced sea ice extent) influence the timing and magnitude of primary (phytoplankton) and secondary (zooplankton) production, and the transfer of that production to higher trophic levels in marine food webs.

This theme session invites presentations and papers that use either qualitative and/or quantitative approaches to determine how oceanographic and ecological processes in marine systems are influenced by atmospheric forcing and climate variability. The focus is on differences in physical processes and conditions (e.g., temperature, solar irradiation, hydrographic conditions/water-column mixing, and nutrient availability) that determine production in the four systems.

Papers addressing how future climate change is likely to influence oceanographic and ecological processes within each system are especially welcome.

Theme session 2: Capelin Ecology and Response to Climate Variation in North Atlantic Marine Systems 

Conveners: Warsha Singh (Marine and Freshwater Research Institute, Iceland) and Sam Subbey (Institute of Marine Research, Norway)

This session invites papers that examine distinguishing characteristics (e.g.— atmospheric forcing, climatic regime, hydrographic conditions, and underlying ecological processes) — of each ecosystem either in isolation or in comparison to understand how these characteristics influence capelin ecology, life-history strategies and population/production dynamics. Papers that use numerical simulations (oceanographic, mathematical/statistical) to link changes in capelin ecology and life-history traits to climate variations are strongly encouraged.

Theme session 3: Impact(s) of Variable Capelin Production on Food Webs in North Atlantic Systems

Conveners: Teunis Jansen (Danish Technical University, Denmark) and Mayumi Arimitsu (United States Geological Survey, Alaska, USA)

For complex reasons, collapses (persistent declines) of capelin stocks have occurred in major North Atlantic marine systems ― including the Barents Sea, waters around Iceland–East Greenland–Jan Mayen, Newfoundland–Labrador Shelf, and the Gulf of Alaska and Bering Sea ― which have had undesirable ecological and economic consequences. In all three systems, collapses of capelin stocks have likely been due (directly and indirectly) to an array of interacting variables, including: natural environmental cycles; predator-prey interactions; climate variability/change, and anthropogenic effects (over-exploitation).

This session invites papers that deal with studies (including comparative studies) on how each of these food webs responded to capelin collapses or changes in capelin abundance, and factors influencing rebuilding of their capelin stocks ― including instances of top-down vs. bottom-up regulation, and degrees of wasp-waistedness within and between these four marine systems.

Theme session 4: Managing Commercial Fisheries for Capelin in North Atlantic Marine Systems Under Climate Change

Conveners: TBA

Commercial fisheries for capelin are conducted in marine systems across the North Atlantic. A prerequisite for effective and sustainable ecosystem-based management of commercial fisheries for capelin is to consider both the population- and ecosystem dynamics of the species.

This session invites papers that critically examine the extent to which life history, tropic interactions, and/or environmental influences on population and ecosystem dynamics are taken into consideration in the design of scientific surveys, and in setting catch limits/harvest rules for capelin in the four ecosystems. We strongly encourage papers that consider multiple levels at which an ecosystem approach to management of capelin fisheries can be adopted and discuss pragmatic operationalization of such approaches e.g., through statistical/mathematical simulations and bioeconomic considerations.