New publication: Movements of sole in the southern North Sea and eastern English Channel from tagging studies (1955-2004)
Tagging has been widely used to study the behaviour, distribution and movement of many commercial fish species on fishing grounds around the UK. Much of the early work in the North Sea focused on plaice (Pleuronectes platessa) and cod (Gadus morhua), and relatively little addressed the movements of sole (Solea solea). However, the results of an international tagging exercise in the North Sea from 1959 to 1963 showed that sole spawned inshore in spring and generally moved offshore to feed in summer and autumn (ICES, 1965). Along the coasts of The Netherlands and Denmark, the inshore migration was thought to be a swift one in spring, associated with water temperatures inshore of 6–7°C. Along the coast of Belgium and England, however, the extent of the movement was thought to be much less than farther north.
Wallace and Watson (1980) described two small experiments on adult sole in the Thames, which showed a generally offshore movement in winter and a return to the same release area to spawn in spring. Data from a number of studies based on tagging of juveniles were collated by ICES (1989). The results indicated a seasonal pattern of movement, with inshore recaptures in the second and third quarters and a more offshore distribution at other times of the year. Also, for the first time, the results indicated movement of juvenile sole between ICES management areas, and in particular between VIId and the North Sea, and between VIId and VIIe.
For management purposes, the sole stocks in ICES Divisions IV and VIId are considered to be separate units. This assumes that there is relatively little interchange of sole between them and that their responses to exploitation by fishing fleets in the two areas can be assessed within the management areas. Tagging studies have provided a means of observing the interchange between management boundaries. This report extends the analysis started by ICES, and reviews the movements of juvenile and mature sole tagged between 1955 and 2004 in the North Sea and the eastern English Channel.
