Sharks caught in the protective gill nets off KwaZulu-Natal, South Africa. 8. the great hammerhead shark sphyrna mokarran (rüppell)

Abstract

Between 1978 and 1993, 209 great hammerhead sharks Sphyrna mokarran were caught in the shark nets which protect the swimming beaches of KwaZulu-Natal. This species constituted 0, 97% of the total shark catch, with a mean annual catch of 13. Catch rates showed a significant decline during the period under review, from 0, 66 to 0, 09 sharks·km-net−1·year−1. Most sharks were caught in the north of the netted region between January and May. Catches at Mzamba, the southern extremity of the netted region, represent the southernmost records of this species on the east African coast. The males ranged in size from 106 cm precaudal length (18 kg) to 264 cm (220 kg) and females from 140 cm (35 kg) to 326 cm (400 kg). Males matured at about 217 cm and females at 237 cm. Very few sharks were found in mating condition. Elasmobranchs were found in 82% of non-empty stomachs. There was a high incidence of stingrays (Dasyatidae), guitarfish (Rhinobatidae) and other bottom-dwelling fish in the diet. © 1995 Taylor & Francis Group, LLC.