Dr Stefan Koenigstein1
1NOAA Southwest Fisheries Science Center, Environmental Research Division, Monterey, United States
The Barents Sea is a sub-arctic shelf sea strongly influenced by climatic variability. In recent years, ocean warming has led to shifts in distribution and productivity of economically important marine fish populations, and substantial management challenges are expected under continuing warming and ocean acidification projected for this century.
We investigated how ecological shifts among marine fish populations in the Barents Sea are co-determined by physiological temperature preference, predator-prey interactions and early life stage processes. Process-based multi-species and recruitment models were developed to integrate experimental and observational data. Adaptation options to shifts for human user groups such as fisheries and maritime tourism were assessed by involving local stakeholders.
Shifts among the major marine fish stocks are projected under continuing warming in the Barents Sea. The high Atlantic cod stock, and herring and mackerel stocks shifting further North, lead to marked food-web mediated decreases in capelin, an important forage fish. Seals and seabirds are negatively impacted through decreased food availability. Dynamic adjustments of fisheries catches could ameliorate these shifts and help to safeguard against possible recruitment failures due to the combined impacts of warming and acidification in the second half of this century.
This work demonstrates how process-based ecological models can improve the integration of available data to investigate shifts in marine ecosystems under multiple climate change drivers, informing ecosystem-based fisheries management and conservation of threatened Arctic species as well as long-term management strategies for rapidly changing Arctic marine ecosystems.
– Studies in biology and philosophy, University of Bremen
– Research scientist, Sustainability Research Centre, University of Bremen
– 2017 PhD thesis on „Ocean Warming and acidification effects on marine fish and ecosystems in the Barents Sea”, Integrative ecophysioloy group, Alfred-Wegener-Institute Bremerhaven
– 2017-18 PostDoc “Social-ecological tipping points in the Northern Humboldt Upwelling system”, University of Bremen
– since 2018 PostDoc at NOAA Southwest Fisheries Science Center / UC Santa Cruz, Climate and Ecosystems Group