KwaZulu-Natal Sharks Board

Overview of the Sharks Board

Promulgated in terms of the KwaZulu Natal Sharks Board Act , 2008 (Act No. 5 of 2008)

The KwaZulu-Natal Sharks Board has been successfully protecting the province’s bathing beaches from shark attack for more than 40 years. Its research into bather protection, with as little impact on the environment as possible, is respected world-wide and there is a continuing exchange of information with overseas countries, notably Australia as well as USA and other countries experiencing shark incidents.

The Board also plays a significant role in supporting the tourism industry that has developed around the annual Sardine Run, relaying information and running an information hotline (083 913 9495) as the shoals make their way up the South Coast. The Sardine Run – usually occurring May to July – affords visitors the opportunity of viewing first hand, the vast shoals of fish and accompanying predators such as seabirds, dolphins, gamefish and of course sharks.

The KZN Sharks Board’s headquarters at Umhlanga is a popular venue for school tours. Visitors are able to view an audio-visual presentation and shark dissection, from which important data is collected for research purposes. Its Durban-based motor cruisers takes members of the public on a shark safety gear experience where they can see firsthand the maintenance operation of the nets off Durban’s Golden Mile at dawn, and then enjoy the opportunistic viewing of dolphins, whales and seabirds that may be in the area.

The KZN Sharks Board constantly seeks a balance between the protection of bathers with the least possible impact on the marine environment. The Board embarked upon a net reduction programme some years ago and total coverage of shark safety gear (nets and/or a combination of nets and drumlines) has gradually dropped from 44km to 23km of the KwaZulu-Natal coastline, without adversely compromising bather safety at popular protected beaches from Richards Bay to Port Edward.

The operations staff are accommodated on site at 11 base stations situated along the KZN Coast. This enables the teams to launch through the surf at first light and begin their task of checking the shark safety gear for any specimens caught overnight, and changing nets that have accumulated marine growth and effecting any minor repairs that may be required.

It is tough, demanding work but morale is high. The Tourism Industry in KwaZulu-Natal owes much to the efforts of these dedicated men and women in keeping our beaches safe from shark attack

Shark attack in South Africa today

An analysis of South African shark attack records over the last four decades has shown some interesting patterns.

Most importantly, the results confirm that attacks are rare events, with an average of only six incidents per year. Since 1990 only 26% of attacks have resulted in serious injury and only 15% were fatal. This equates to an average of one serious shark-inflicted injury every year and one shark-inflicted fatality every 1.2 years along some 2000 km of coastline from the Mozambique border to Table Bay (Cape Town).

Initially most attacks took place on swimmers in warm, shallow waters on KwaZulu-Natal beaches, but the shark nets, now concurrently with the drumlines, have greatly reduced the number of these incidents in the province to less than 1 per annum.

There have been only two serious attacks at protected beaches in the last 30 years. Both involved surfers who were bitten in very clear water by a great white shark Carcharodon carcharias. The last attack at a protected beach took place in 1999, which bears testimony to the success of the shark nets in reducing shark attack.

Shark Nets, Drumlines, and Safe Swimming

Most of the shark nets deployed by the KZNSB are 214 m long and 6 m deep and are secured at each end by two 35 kg anchors; all have a stretched mesh of 51 cm. The nets are laid in two parallel rows approximately 400 m offshore and in water depths of 10-14 m. A drumline consists of a large, anchored float (which was originally a drum) from which a single baited hook is suspended. Most beaches are protected either by two nets or by one net and four drumlines, but the quantity of gear varies from beach to beach. Durban, the largest coastal city and holiday resort in South Africa, has 17 nets, each 305 m in length, which cover all the popular swimming beaches between the mouth of the Umgeni River and the harbour entrance.

The KZNSB boat crews service the nets, every Monday through Friday, weather permitting. Only four of the 15 skiboats operate from harbours, with three boats based at Durban harbour and the forth at Richards Bay. All the other craft have to launch though the often heavy surf to reach the nets.

Reducing Mortalities

Between 2005-2009 the average annual catch was 591 sharks (the bulk of the catch comprising 14 species, 13.3% released alive), 201 rays (mostly comprising seven species, 50.8% released alive), 60 turtles (mostly comprising two species, 54.3% released alive), 43 dolphins (three species) and 30 teleosts (bony fish). Although the KZNSB, through monitoring trends in catch rates of each species, believes that catches of most of the species concerned are sustainable, it is committed to minimising any environmental impact associated with its mandate of protecting sea users from shark attack. Several initiatives have been implemented or are being evaluated in an attempt to reduce mortalities without jeopardising bather safety.

Permanent removal of all nets from selected beaches

The provision of a shark netting service is expensive and historically certain beaches were poorly utilised for a number of reasons. It was therefore decided in 1994 that the cost of providing the netting service at these beaches could not be justified and that all the nets should be removed. Such localities included Tinley Manor and La Mercy to the north of Durban and Ifafa and Mtwalume to the south.

Net reduction

A major initiative has been directed at reducing the number of nets at individual beaches. Logically, given that the nets are fishing devices, fewer nets will catch fewer animals. The initial impetus for this research was provided by a comparison of the KZNSB’s operation with those of its counterparts in New South Wales and Queensland, Australia. In both Australian states, considerably less shark fishing equipment is deployed per protected beach than in KwaZulu-Natal.

Drumlines – an alternative to nets

Another means of reducing environmental impact is the introduction of drumlines in place of some of the remaining nets, such that beaches are protected with a combination of nets and drumlines. A drumline consists of a shark hook suspended from a large anchored float. Drumlines take a reduced catch of harmless animals, compared to a net.

Dolphin pingers

Unfortunately, the shark nets catch dolphins. An annual average of 12.6 common dolphins (Delphinus capensis), 23.4 bottlenose dolphins (Tursiops aduncus), and six Indo-Pacific humpback dolphins (Sousa chinensis) were caught between 2005-2009. Due to a relatively small population size, it is actually the catch of humpback dolphins that is of most concern.The KZNSB has initiated two research projects aimed at determining the efficacy of dolphin deterrent devices in reducing catches. This work has been conducted through generous support from the Endangered Wildlife Trust.

Research at the KZN Sharks Board

The Board employs three biologists whose primary aim is to analyse information taken from catches in the shark nets. This information is used to:

• Improve our understanding of the biology of those species of sharks and other animals caught in the shark safety gear.
• Assess the impact of mortalities on local stocks.
• Reduce mortalities in the shark safety gear without jeopardising the safety of beach user.

Every animal caught is identified, sexed, measured and recorded. Live sharks found in the shark safety gear are now not only tagged and released but many are also injected with tetracycline to validate age and growth studies. Dead sharks that are not badly decomposed are brought into the laboratory, where they are weighed and measured. They are then kept frozen until they are dissected by technical staff, who record various biological data. A section of the vertebral column is removed for ageing studies and some jaws are kept for the KZNSB reference collection. Additionally, various tissues are sampled for a variety of different studies.

The KZNSB is publishing, in the African Journal of Marine Science Volume 7 (1988) et seq., a series of papers on the biology and catch statistics of the shark species commonly caught in the nets. These and many other KZNSB publications (view list) are available on request.

Tagging

The KZNSB has been an active member of the South African National Tagging Program since 1984. The Tagging Program is administered by the Oceanographic Research Institute (ORI) and since its inception in 1984, 4689 registered members have tagged over 219 000 fish of about 350 species. Most of the participants are volunteer anglers, but several research institutes and universities also participate.

Recaptures

The overall recapture rate of sharks released from the nets and drumlines is about 4%. It is interesting to note that the recapture rate of free-swimming raggedtooth sharks tagged by divers, where there is no capture stress, is higher (10.2%) than that of raggies tagged from the nets and drumlines (4.7%). Recapture rates for other net-tagged species vary, e.g. 4.8% for the blacktip and 4.6% for the tiger shark.The overall recapture rate for injected sharks is 4.6% and 6.5% for the giant guitarfish. To date none of the other tagged rays has been recaptured. 

Ageing of sharks

The conservation, management and rational utilisation of shark stocks are receiving increasing global attention. In a local context it is essential to have accurate information on the biology and life history of the various species being exploited in the shark nets to understand the impact of the netting program on these shark populations. 

Opportunities for visiting researchers and students

The KZNSB is always seeking ways of obtaining as much scientific information as possible from any animals caught in the shark nets and on the drumlines. It is therefore receptive to requests from other scientists for material. For example tissue samples are collected, on request, for genetic or pollution studies by scientists, who supply sample vials and cover all postage/freight costs. Researchers are welcome to visit the KZNSB to collect their own material, but laboratory and office space are extremely limited. One PhD student has collected a wide variety of copepod and helminth parasites from sharks and rays caught in the nets.

Conservation

A combination of factors has led to global concerns about the conservation of sharks and their close relatives, the skates and rays. The KZNSB shares these concerns…” 

Why should we be concerned about shark conservation?

Sharks tend to be at or near the top of the food chain. As apex predators, they are believed to play an important role in regulating numbers of the prey animals on which they feed. Also, they have survived largely unchanged for some 400 million years and form a unique and fascinating group of animals. They have the potential to be important in fields such as human medicine, and, when fished responsibly, can provide a valuable source of food.

The life history of sharks is such that they are very vulnerable to overfishing. Typically, sharks grow slowly, mature late and give birth to few young. These characteristics mean that only a small proportion of a given shark stock can be caught on a sustainable basis. Also, if a shark stock has been overfished, it takes a long time to recover.

Threats to sharks

Historically, shark fisheries tended to be small-scale. Since the 1980s, however, sharks have been targeted increasingly. Declining catches of traditional food fish led to a search for alternative resources with which to feed the world’s growing human population. Sharks were obvious candidates. One estimate in the 1990s was that the global shark and ray catch may exceed 1.3 million tons, or more than 100 million individuals. Although this is a small percentage of the world’s total fish catch, there is concern that catches may be unsustainable in the case of some shark populations.

Legislation protecting sharks in South Africa

The Marine Living Resources Act (Act 18 of 1998) controls the exploitation of marine plants and animals in South African waters. There are a small number of regulations that pertain to sharks, most but not all of which are summarised below. The great white shark is totally protected; in 1991 South Africa being the first country in the world to do so. If caught or killed unintentionally, a white shark must be kept in a whole state and handed over to a fisheries officer. No white shark, part or product thereof may be sold. In 2005, the whale shark and the basking shark were added to the prohibited species list (pdf download).

Other shark species may be caught for recreational and commercial purposes. An important item of the legislation states that finning – the process of removing the fins and then discarding the carcass – is prohibited. Fins may be separated from carcasses but must be landed together with a fin-to-carcass (dressed-weight) ratio of 8% for domestic vessels and 5% for foreign vessels.

Four shark species are classified as recreational species in that they can be caught in the recreational fishery but they or parts thereof may not be sold. They are the raggedtooth shark Carcharias taurus, the spotted gully shark Triakis megalopterus and two species of small catsharks, the leopard catshark Poroderma pantherinum and the striped catshark P. africanum. There is a daily bag limit of one per species, but a total bag limit of 10 sharks of any species. Commercial fishermen are not restricted by these bag limits, but limiting the number of licences allocated within a particular sector controls the total fishing effort. There have been complaints of sharks hooked on rod and line being maimed because they prevent the anglers from landing their target fish, either by taking the bait directly or by eating the fish once they are hooked. The regulations state that there may be no dumping or discard at sea of any fish species for which there are restrictions. This implies that the maiming of sharks is illegal, albeit that the legislation is aimed at resource management rather than preventing cruelty.