Photo: T.Holm/Azote
Published: 2013-06-26
New research points to grim future for Baltic Sea cod
Using biological ensemble modeling a group of researchers, among them researchers from BNI Sweden, show that Baltic Sea cod are affected by what they eat. Climate change leads to a warmer and less saline Baltic Sea, where cod become fewer and less able to withstand heavy fishing pressure.
Fewer cod in the future
In 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.

Ensemble modeling
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:

  1. disentangling climatic from ecological sources of variation in species response to changing environmental and anthropogenic pressures,
  2. identifying key ecological processes causing, and
  3. finding scientific conclusions and management solutions robust to the uncertainties of food web processes.

Sustainable management
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.

Read more
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".

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Web editor: Marmar Nekoro

Updated: 2013-06-26
Baltic Nest Institute Sweden
Baltic Sea Centre, Stockholm University
SE-106 91 Stockholm, Sweden, +46-8-16 37 18
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