Bottom-up effects on zooplankton biomass persist from spring to summer ...

• Main Authors: Kvile, Kristina Øie, Langangen, Øystein, Prokopchuk, Irina, Stenseth, Nils Chr., Stige, Leif Chr.
• Format: Conference Object
• Language: unknown
• Published: ASC 2015 - Theme session S 2024
• Subjects: Oceanic Northeast Atlantic ICES Ecoregion; Ecosystem observation, processes and dynamics; Barents Sea; Norwegian Sea; Calanus finmarchicus; Northeast Atlantic
• Online Access: https://dx.doi.org/10.17895/ices.pub.25682793; https://ices-library.figshare.com/articles/conference_contribution/Bottom-up_effects_on_zooplankton_biomass_persist_from_spring_to_summer/25682793

No abstracts are to be cited without prior reference to the author.Marine zooplankton populations are generally believed to be bottom-up controlled. However, most studies from the Norwegian Sea-Barents Sea area (NS-BS) have focused on top-down control by planktivorous fish. We quantify bottom-up effects on Calanus finmarchicus biomass by including particle tracking in statistical analyses of survey data from NS-BS between 1959 and 1993. Spatial variation in C. finmarchicus biomass in summer is positively related to back-calculated temperature in spring, reflecting that more biomass originates from warmer areas closer to the core overwintering areas in the Norwegian Sea. However, a warm spring does not generally result in overall increased summer biomass. In warm springs, overall biomass is generally high, and population growth from spring to summer is lower than in cold years. Further, C. finmarchicus biomass in summer relates positively to increased wind in spring when the mixed-layer-depth (MLD) is ...