New research points to grim future for Baltic Sea cod
Fewer cod in the futureIn the latest issue of Ecological Applications a group of researchers, among them researchers from BNI Sweden, use the "biological ensemble modeling approach" to simulate the long-term response of cod to future fishing and climate change.
The researchers have used seven different ecological models, ranging from single-species to food web models. All models point to the same conclusion: fewer cod in the future. The combination of heavy fishing pressure and climate changes leading to a warmer and less saline Baltic Sea prevents the recovery of cod populations.
Cod affected by what it eats
Species interactions greatly influenced the simulated response of cod to fishing and climate, as well as the degree to which the statistical uncertainty of climate trajectories carried through to uncertainty of cod responses.
This points to the importance of models taking into account predator-prey feedbacks.
The study demonstrates how the biological ensemble modeling approach makes it possible to evaluate the relative importance of different sources of uncertainty in future species responses.
Ensemble modeling decrease uncertainty by:
- disentangling climatic from ecological sources of variation in species response to changing environmental and anthropogenic pressures,
- identifying key ecological processes causing, and
- finding scientific conclusions and management solutions robust to the uncertainties of food web processes.
Increased knowledge of ecological processes can significantly increase the accuracy of estimates of the biomass of cod in different areas. Modeling can be used to develop scenarios for how future fishing pressure and climate changes affect this key species.
Biological ensemble modeling approaches that address species responses to human use and climate change may therefore prove successful to further both marine science and management.
The article and its abstract is available here
Swedish article from SLU "Färre torskar i framtidens Östersjö"
Swedish article from SVT "Färre torskar i framtidens Östersjö".