CS 1: Barents/Norwegian Sea

Description of work

In UNCOVER, existing multispecies models (GADGET, STOCOBAR) will be enhanced. The GADGET framework (www.hafro.is/gadget, Begley and Howell 2004) developed during the EU project dst2 (2000-2003) can be used for modelling the interactions between cod, herring and capelin in the Barents Sea. A single-species, single-area closed life-cycle GADGET model for cod already exists (Bogstad et al. 2004), and this will be extended to a cod-capelin-herring (and minke whale) area-structured model. This work is the main part of the Barents Sea case study within the EU project BECAUSE (2004-2007). STOCOBAR is a single-area multi-species model focusing on predation by cod and the effect of prey consumption on cod growth. Some results of the model are reflected in Filin (2004).

Results from studies on single-species population dynamics of cod and herring (maturation, fecundity and early life-history population dynamics)and species interactions in WP1-3 will be formulated as process models for maturation/fecundity/recruitment, migration/drift, growth and consumption/mortality for use in GADGET and STOCOBAR. Parameter estimates for the relevant process models will then be made using GADGET and STOCOBAR.
The work on the individual process models and the further work on GADGET and STOCOBAR will provide increased qualitative and quantitative understanding on the processes leading to collapse and recovery. In addition the case study will use the “Framework for the Evaluation of Management Strategies (FEMS)??? to simulate the effect of the current and new management strategies on the ecosystem as a whole.

Firstly there will be a selection of management regimes, environmental conditions and stock levels to examine. Existing harvest control rules for all three stocks will be used as a “base case???.  Together with the WP4 leaders, the operating models will be incorporated within the FEMS/FLR program (see WP4 description). This may either be done by reformulating the GADGET and STOCOBAR models within this program, or by incorporating the models directly within the program. In either case the evaluation of the success or otherwise of the different management recovery strategies will be directly comparable with that conducted in the other case studies. Also, assessment models for all stocks must be implemented in R (the XSA model used for cod is already implemented). The observation error model needs to be described and implemented for all stocks. Multiple runs will be conducted for each combination to obtain uncertainty estimates, given errors in data collection, stock recruitment variability and possibly also climate variability. Alternative recovery paths for cod, herring and possibly capelin will be explored, and stock recovery under different combinations of these factors will be evaluated. This is the part run by the FEMS program, which coordinates and automates the different sections.

Stakeholder links

The management bodies for the stocks in this case study are The Joint Norwegian-Russian Fisheries Commission for cod and capelin, and the 5-part group (Norway, Russia, Faroe Islands, Iceland, EU) for the herring. The majority of the fishing fleet dependent on these Barents Sea fish stocks also comes from these countries. Other relevant stakeholders include NGOs and possibly local coastal community organizations. The results from the project will be communicated to the major stakeholders, including national governments, fishermen's organizations and relevant NGOs. An interesting point is that the majority of stakeholding countries prosecuting fisheries in this area are not in the EU, and have a different management policy than the EU's common fisheries policy.

Read more:

Background information to this case study area

List of references

To top