Geremy Cliff, Zambezi sharks and shark attacks at Port St Johns, A work in progress
Channel: African Campus
Date: 2013-06-13

Oral Presentation

Geremy Cliff1,2, Paul von Blerk1, Rodney Haestier3 and Paul Cowley4
1KwaZulu-Natal Sharks Board, Umhlanga
2Biomedical Resource Unit, University of KwaZulu-Natal
3The Creek, Port St Johns
4South African Institute of Aquatic Biodiversity, Grahamstown

Following three fatal shark attacks in 2009 at Second Beach, the most popular swimming beach in the Port St Johns area, the Department of Environmental Affairs (DEA) commissioned the KwaZulu-Natal Sharks Board to investigate possible causes and potential solutions and to undertake a shark biodiversity study of the area. Zambezi sharks Carcharhinus leucas appeared to be the culprit. Several juveniles of this species, many of them with recently healed umbilical scars, were caught in the Umzimvubu River, confirming that this river is an important nursery ground. Acoustic transmitters were surgically inserted into three adults caught off the river mouth and eight juveniles caught in the river. Two series of listening stations was deployed, one in the lower reaches of the river and the other in the sea behind the surfzone. One of the adults remained in the area and was detected through the winter, leaving the area for a 54-day period in spring. The juveniles made extensive use of the lower reaches of the river; only two were detected at sea directly off the mouth. More acoustic monitoring is being currently being undertaken.
The problem of shark attack at Second Beach persists, with the most recent being on 25 December 2012, bringing the total to seven attacks in six years, all of which were fatal. The local community want protection against further attacks and the municipality has submitted a request to the DEA for the installation of shark nets.