Occurrence of Carcharias taurus in nursery areas of the Eastern and Western Cape, South Africa

Abstract

This study was initiated to investigate the occurrence, size and stage of sexual maturity of ragged tooth sharks (Carcharias taurus) in their putative nursery areas. Information on size and seasonality of catches was obtained from the National Marine Linefish System revealed that juvenile and immature individuals occur in the Eastern Cape throughout the year and make up ~80% of the line-fishing catches. Their occurrence west of Storms River along the south coast of the Western Cape is more common in summer. Individuals large enough to be sexually mature are found in the Eastern Cape almost throughout the year. This suggests that the Eastern Cape is both the both primary and secondary nursery area for this shark. The smallest individuals (<9 kg) occur mainly from September to December. Eastern Cape samples comprised 95 males ranging between 84 cm (4.5 kg) and 262 cm total length (120 kg) and 166 females of 985 cm (5.5 kg) to 288 cm (163 kg). Size at maturity conformed to previous studies and one pregnant female was recorded in October. Catches were from the intertidal zone to 100 m. Underwater observations showed the sharks to prefer high-relief reefs with caves and gullies by day.