Bestandsvurdering og forvaltning af forbundne bestande

Assessment and management of linked stocks
The purpose is to develop operational assessment models capable of linking stocks.
Fish stocks are not isolated units. They eat and are eaten by other stocks. Furthermore, the partitioning into stock units is sometimes arbitrary and to some extent determined by management concerns, so some exchange between the defined stock units must be expected.
Single stock assessment models does not include the effects from linking stocks. On the other hand, classical ecosystem and multi-species models are not operational for practical assessment and management, as they are designed to estimate all the detailed interactions between every age (or length) group of every stock in the system. Further, the classical ecosystem and multi-species models require data sources, which are not routinely collected (e.g. stomach samples).
This project has developed operational models, which are directly applicably in the scientific management process. They don't aim to describe all details, but only to capture the main effects connecting the selected stocks. The models only require the same standard data sources, which are already used for the single stock assessments.
The research will be continued as part of the Horizon2020 project PAradigm for Novel Dynamic Oceanic Resource Assessments (PANDORA), where it will be formally evaluated against the classical ecosystem and multi-species models.