Movements of the New Zealand school shark, Galeorhinus galeus, from tag returns

During the period March 1985 to January 1997, 3950 school sharks, Galeorhin us galeus (L), were tagged, mostly opportunistically during other research activities. Up to July 1997, 207 sharks had been recaptured. The best recov ery rates were from sharks ragged with internal (8.8%) and dart (6.5%) tags and first caught by line methods (22%). The maximum distance travelled was 4940 km, the maximum time at liberty was 3505 days (9.6 years), and greate st average speed was 22.8 km/day. Most sharks (76%) moved less than 500 km, but the larger movements included 10% of sharks which had travelled over 1 700 km to southern Australia. The proportion of sharks recaptured in their home Quota Management Areas (QMA) was 53% overall. However, the distance tr avelled increased significantly with time at liberty. After 2 years at libe rty, only 22% of sharks were recaptured within a release QMA and 23% were r ecaptured in Australia. These findings suggest that future assessment of sc hool shark fisheries within New Zealand waters should consider the species as one stock with a relatively high emigration rate to Australian waters.