Plankton size and planktivore competition along the Norwegian coast and fjords: ecological implications of warmer and darker waters

Informations

Funding country

Norway

Acronym

-

URL

-

Start date

1/1/2023

End date

12/31/2027

Budget

983,754 EUR

Fundings

Abstract

Coastal waters are some of the most productive of marine ecosystems. In a changing climate, coastal waters are getting warmer and darker, and the ecological implications are unknown. In this project we will study how the foraging opportunities for pelagic fish (herring, sprat, mackerel etc.) may change as a result of these two climate change associated stressors. Pelagic fish are visual foragers, and the size and visibility of their prey (zooplankton) may be more important than prey abundance for fish foraging efficiency and production (Aarflot et al. 2020 MEPS). Both warming and coastal water darkening are expected to alter the size structure within plankton communities that have rapid life cycles and respond fast to changes in the environment. In this project we will expose historical zooplankton samples to new technology for revealing community size structures, and incorporate plankton size in an existing ecosystem model for Norwegian coastal waters. With this we aim to enhance our understanding of how temperature and light affects the size structure within planktonic communities along the Norwegian coast – both historically and in the future. If fish become less efficient predators, jellyfish may gain a competitive advantage as they do not rely on vision or prey size to localize their food. We will therefore also assess the competitive relationship between fish and jellyfish in selected Norwegian fjords, and the potential for regime shifts towards more jellies and less fish in the future.