Baltic zooplankton cascades

Sampling of the ctenophore Mnemiopsis leidyi in the Gullmars fjord
BAZOOCA final report
BAZOOCA briefing on key results
Year 1 progress report
Year 2 progress report
For more relevant publications, visit (category BONUS+ reports)

Begin date 1.10.2008
End date 30.9.2011
Grant: 1 962 881€

The recent introduction of the alien ctenophore Mnemiopsis into the Baltic is alarming and may exacerbate existing perturbations such as eutrophication, over fishing, climate change and invasive species. We aim to test the overall hypothesis that effects of Mnemiopsis will cascade in the pelagic food web in the Baltic. By use of models, experiments and field studies we will quantify ecosystem consequences of Mnemiopsis in the pelagic food web, from microbes to gelatinous top predators. Focal topics include predation on cod eggs and larvae, changes in water clarity leading to regime shifts from fish to jellyfish and couplings between plankton and microbes. Interactions and cascading effects will be quantified within natural spatial (Baltic proper, Bothnian Sea, Bothnian Bay) and environmental (oxygen, temperature, salinity, light, N, P) gradients. We will monitor Mnemiopsis synchronically with environmental and biological parameters relevant for other trophic levels. The project gathers the best competence available to address these processes. State-of-the-art techniques will be applied in field, laboratory and modelling studies. The altered pelagic community balance in the Baltic may have severe consequences for biodiversity. Negative socio-economic consequences for fisheries and industries may be significant, but the project will provide fundamental insights for policy making and prudent fisheries and ecosystem management of the Baltic.


Mnemiopsis, cod, invasive species, fish eggs, cascades, light

List of Participants and Principal Scientists

Göteborg University, Sweden

Peter Tiselius (Coordinator)

National Institute of Aquatic Resources, Technical University of Denmark, Denmark

Thomas Kiørboe

Kalmar University, Sweden

Lasse Riemann

Umeå University, Sweden

Ulf Båmstedt

Swedish Meteorological and Hydrological Institute, Sweden

Lars Johan Hansson

University of Helsinki, Department of Biological and Environmental Sciences, Finland

Jorma Kuparinen

University of Bergen, Norway

Dag Aksnes

Please visit the BAZOOCA webpage for more information!