Short Communications

First documented southern transatlantic migration of a blue shark Prionace glauca tagged off South Africa

Published in: African Journal of Marine Science
Volume 32, issue 3, 2010, pages: 639–642
DOI: 10.2989/1814232X.2010.540777
Author(s): C da SilvaBranch Fisheries, Department of Agriculture, Forestry and Fisheries, South Africa, SE KerwathBranch Fisheries, Department of Agriculture, Forestry and Fisheries, South Africa, CG WilkeBranch Fisheries, Department of Agriculture, Forestry and Fisheries, South Africa, M MeÿerOceans and Coasts, Department of Environmental Affairs, South Africa, SJ LamberthBranch Fisheries, Department of Agriculture, Forestry and Fisheries, South Africa

Abstract

The first documented recapture of a South African-tagged juvenile blue shark Prionace glauca off Uruguay lends weight to the hypothesis of a single blue shark population in the South Atlantic. The presence of neonate blue sharks with umbilical scars and females with post-parturition scars, as well as the high frequency of small juveniles in research longline catches, confirm the existence of a parturition and nursery area off South Africa. The final positions of three tagged sharks suggest that large-scale movement patterns in the South Atlantic are a mirror image of movements in the North Atlantic, with sharks using the north-westerly Benguela Drift to migrate into the tropics and ultimately across into South American waters. The confirmed existence of a parturition and nursery area off the south coast of South Africa and the movement of sharks into both adjacent ocean basins suggest that the southern African blue sharks are part of a single stock that straddles the South Atlantic and Indian oceans, and possibly the entire Southern Hemisphere.

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