Assessment and management of linked stocks (39325)

The purpose of this project is to develop operational models for linked stocks. Fish stocks are not isolated units. Fish eat, and are eaten, by fish from other stocks. The definition of fish stocks is often arbitrary or determined by management considerations. The bottom line is that some linkage must be expected between the defined stocks. For some stocks these effects are essential to give reliable assessment and management.

Single species assessment and management does not include effects from linked stocks. Ecosystem and multi-species assessment models are not practically operational for assessment and management. These models are designed to describe all interactions between all important species in an ecosystem. These models often attempt to estimate detailed effects between all length- or age groups. These models often require data, which are not routinely available.

This project will develop models, which are directly applicable in the scientific advice. The aim is not to describe all interactions, but simply to harvest the main benefits of considering two or more stocks in a joint model. The aim is to identify few links between the stocks, which describes the main part of the interaction, and to base the models only on standard data sources.

The models will be developed to be generally applicable, but applied to two important cases (Cod EB and WB, and Cod stocks around Kattegat). Final tool will be available via stockassessment.org, so it can easily be applied to any stocks defined there.

Funding
The project is funded by the European Maritime and Fisheries Fund (EMFF) and the Danish Fisheries Agency.

Research area: Marine Living Resources