A recent study published in ICES Journal of Marine Science outlines a strategy for implementing ecosystem-based management for fisheries in the Baltic Sea. Photo: G. Aneer/Azote

Ecosystem-based management

The pisces as parts of the whole

A strategy for implementing ecosystem-based fisheries management in the Baltic Sea

Story highlights

  • The theory behind ecosystem-based fisheries management is well developed but still rarely practiced in the Baltic Se
  • Instead, fisheries management is often based on accounts of single species
  • As an alternative 12 experts present the “integrated ecosystem assessment framework” as a tool for quantifying relevant natural and socio-economic factors

In recent years, ecosystem-based management has stepped in as a key paradigm for management of marine resources worldwide.

What sets ecosystem-based management apart from more conventional approaches is that it addresses the impact of many different uses of marine resources, as well as climate change, on a number of different ecosystem components.

This means looking at the bigger picture for management decisions in a different way than is the current practice in most parts of the world. A recent study published in ICES Journal of Marine Science outlines a strategy for implementing ecosystem-based management for fisheries in the Baltic Sea.

"The theory behind ecosystem-based fisheries management is well developed, but it is still rarely practiced. Instead, fisheries management is often based on accounts of single species, as is the case in the Baltic Sea," says Thorsten Blenckner, researcher at the centre and co-author of the study.

"This can have major effects on the ecosystem as a whole, as it doesn't consider many of the interactions and feedback that we know to be important," he continues.

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Mapping the road to success
In the study, Blenckner, together with a team of 11 other experts, present the Integrated Ecosystem Assessments framework as a tool for quantifying relevant natural and socio-economic factors. They identify three key indicator groups that need to be included in such an assessment:

- Fish stock status and structure indicators other than biomass and abundance
- The state of the environment in the sea, both concerning living organism and abiotic factors such as oxygen and nutrients.
- Early warning signals that can indicate changes in the ecosystem.

A resilient point of entry
The Baltic Sea is an example of a system that has undergone a regime shift, a critical change in the structure and function of the system as a whole. Regime shifts can occur when the resilience of a system is severely decreased, and are difficult if not impossible to reverse. They often mean that an ecosystem goes into a state that is less desirable where for example production of ecosystem services is deteriorated.

"The strategy that we describe in the study implicitly requires a resilience approach to ecosystem management, where we would look at the state of a system as a whole"

Thorsten Blenckner, co-author

Thorsten Blenckner believes identifying an implementing early warning signals can help avoid crossing the threshold that leads to a regime shift. This is an important factor in ensuring or rebuilding health and resilience in the Baltic Sea and in other marine systems.

Manageable management
A typical difficulty in management is how to translate ecological information and data into decision criteria.

The strategy that is outlined in the study is based largely on existing studies and models.

"In the Baltic Sea, and in many other marine systems, the knowledge, data and tools for integrated ecosystem assessments and ecosystem-based fisheries management are readily available. Considering the benefits of this type of management approach we argue that they should be applied implemented sooner rather than later," Blenckner concludes.

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Related info

Citation

Mollmann, C., M. Lindegren, T. Blenckner, L. Bergstrom, M. Casini, R. Diekmann, J. Flinkman, B. Muller-Karulis, S. Neuenfeldt, J. O. Schmidt, M. Tomczak, R. Voss, A. Gardmark (2013) Implementing ecosystem-based fisheries management: from single-species to integrated ecosystem assessment and advice for Baltic Sea fish stocks, ICES Journal of Marine Science. doi:10.1093/icesjms/fst123

Thorsten Blenckner is a researcher at the centre. His main research interest is in whole ecosystem processes and multiple stressors, for example the complexity of the Baltic Sea ecosystem.