>>What are the problems?

Benefits of CODYSSEY

In the short term, reliable assessment of stocks becomes increasingly important as stock numbers fall or become more variable. The research detailed in CODYSSEY will contribute towards the development of more effective stock assessment methods by identifying changes in the catchability of fish in space and over time. By integrating environmental parameters into individual based models, CODYSSEY will provide a flexible and adaptable predictive tool for assessing changes in the vertical distribution and behaviour of cod.

In the medium term, sustainable and rational management of fishery resources must be based on high quality biological information. Catch control measures designed to manage the population abundance of fish stocks are, for practical reasons, applied at spatial scales that may be inappropriate when regional complexities in stock structure are considered. CODYSSEY places a major emphasis on understanding the patterns, rates and limits of horizontal migration in cod, how these are related to environmental variables and how migrations determine seasonal patterns of distribution i.e. the availability of individuals to fishing. Knowledge of spatial dynamics will assist with the medium term development of the CFP and help in the design of robust multi-annual technical measures to conserve cod stocks.

In the longer term, CODYSSEY will provide a number of management relevant research outputs that will contribute to the ongoing evolution of the CFP and the fisheries science tools that support it. Explicitly, these will be: (a) an increased understanding of cod spatial dynamics, and the relationship between cod distribution and climatic change; (b) predictive models of cod vertical distribution and behaviour, of relevance to stock assessment survey design and interpretation; (c) a calibrated research method for analysing and interpreting the behaviour of cod populations from otoliths; (d) specific and testable management hypotheses (e.g. evaluation of potential of closed areas); and (e) contributions to fisheries assessment and management models as a result of redefinition of behavioural assumptions. Furthermore, by using a cross-ecosystem approach to test specific behavioural hypotheses, our understanding of the interaction between behaviour and environment, especially temperature, will be accelerated, enabling the prediction of the response of cod stocks to environmental change.

>> What are the problems?