The migrations of tope, Galeorhinus galeus (L), in the eastern North Atlantic as determined by tagging

• Published in: ICES Journal of Marine Science
• Main Authors: Holden, M. J., Horrod, R. G.
• Format: Text
• Language: English
• Published: Oxford University Press 1979
• Subjects: Articles; Petersen; North Atlantic
• Online Access: http://icesjms.oxfordjournals.org/cgi/content/short/38/3/314; https://doi.org/10.1093/icesjms/38.3.314

Migrations of tope in the eastern North Atlantic, based on the recapture of 32 tope from a total of 491 released off the south coast of England and the north coast of Wales in the period 1957 to 1976, are described. The tags used were Petersen discs and rototags. The longest recorded migration of 2526 km was that of a tope recaptured at 28°00'N 16°00'W.One possible interpretation of the pattern of returns is that tope make a southerly migration from January to September and a return northerly migration from October to December. An alternative interpretation is that the majority of tope remain in the area of tagging throughout the year. The number of returns does not allow this inconsistency to be resolved. A possible reason suggested for the inconsistency is that immature and mature tope have different migration patterns. The relative return rate of Petersen discs to rototags was 1:4–75. All of the returns, with one exception, from south of 44°N were of tope tagged with rototags. It is concluded that rototags are better than Petersen discs for this type of experiment.