Publication Abstract

Spatial dynamics of Atlantic cod (Gadus morhua) in the North Sea: results from a large-scale electronic tagging programme. ICES presentation

Spatial dynamics of Atlantic cod (Gadus morhua) in the North Sea: results from a large-scale electronic tagging programme. ICES presentation

*David Righton, *Victoria Quayle, Francis Neat, Martin Pedersen, Peter Wright, *Mike Armstrong, Henrik Svedang, Vicky Hobson & *Julian Metcalfe

Electronic tags have revolutionised research into the behaviour of free-ranging marine fish.  With the right analytical tools they can provide insights into movements, habitat occupation and environmental preferences.  Here, we report on the results of a large-scale electronic tagging programme of Atlantic cod in the North Sea, spanning the years 1999 to 2008.  During this time, over 1000 tags have been deployed on cod between 27cm and 110cm, and over 300 of the tags have been returned yielding over 40,000 days of data.  We used a range of different geolocation techniques to determine the daily locations of each cod, and therefore ascertain the scale and rate of their movements.  We have used this dataset to describe fundamental features of cod ecology, such as the balance between homing and resident behaviour, the location of feeding and spawning grounds (and the migratory pathways between them), and the seasonality of migration and its impact upon sub-stock structure. The results provide a step forward in our understanding of how Atlantic cod exploit and utilise their environment and, as a result, have wide-ranging implications for our expectations of how cod stocks may recover following depletion.

*David Righton, *Victoria Quayle, Francis Neat, Martin Pedersen, Peter Wright, *Mike Armstrong, Henrik Svedang, Vicky Hobson & *Julian Metcalfe

ICES CM Conference, 22 - 26th September 2008, Halifax, Canada