BYCATCH

Bycatch is commonly defined as all non-target species caught by a fishery, whether discarded (often at sea) or landed.

It’s reported that 99 out of the 204 species of sharks, rays, skates and chimaeras that occur in southern Africa are targeted regularly or taken as bycatch. That means that nearly 50% of sharks and rays in our waters are fished, in one way or another. From 2010 to 2012, the reported “dressed catch” (the weight of the shark catch after their gills, guts and head have been removed and discarded at sea) was estimated to be 9 143 tonnes, meaning that two-thirds of the reported catch in southern Africa was bycatch (da Silva et al. 2015).

Most shark bycatch occurs in longline, gillnet, and trawl gear fisheries (Stobutzki et al. 2002; Jordan et al. 2013). Aside from the direct impacts on shark and ray populations and their ocean ecosystem, incidental catches can also be detrimental to fishers:  when sharks are not retained for economic use, removing them from the fishing gear can be both costly and dangerous. When sharks are retained, they take up space on the boat and can cause fishers to take more trips out to sea; as a result, most incidental shark catches are not retained, and in most cases, are not reported (Campbell and Cornwell 2008).

Fisheries are directly linked to bycatch. For example, juvenile sharks can be caught in large numbers in purse seine (nets that typically target species like sardines (http://wwfsassi.co.za/fish-detail/85/) in South Africa) and trawl (nets that typically target species like Cape horse mackerel (http://wwfsassi.co.za/fish-detail/62/) at different depths in South Africa) fisheries, contributing to long-term declines in populations that may not be immediately apparent. There are also dedicated shark fisheries that specifically target certain shark species in South Africa.

Recreational fishing is fishing for pleasure or competition (sport fishing). It can be contrasted with commercial fishing, which is fishing for profit, or subsistence fishing, which is fishing for survival. Many different species of sharks and rays are targeted by recreational fishers. Some of the limitations on which sharks can be fished, and which can’t, gets confusing: four shark species can be fished by recreational fishers with special permits, but not traded commercially. These are the ragged-tooth shark (Carcharias taurus), the spotted gully shark (Triakis megalopterus), the leopard catshark (Poroderma pantherinum) and the striped catshark (Poroderma africanum). The great white shark is fully protected by the Marine Living Resources Act (MLRA), and any fishing for the whale shark (Rhincodon typus), basking shark (Cetorhinus maximus) and the sawfishes (Pristis spp.) is also banned.

There are currently 37 beaches along the KwaZulu-Natal (KZN) coastline that have “shark safety” gear installed.

These are in the form of either gill nets or drumlines. The gill nets are usually 214m long and 6m deep and secured at each end by two 35 kg anchors. These nets are laid parallel and staggered 400m – 500m offshore and in water depths of 10-14m. They all have a stretched mesh of 51cm which catches any sharks (and other animals such as turtles, rays and dolphins) larger than this size. Gill nets are commonly used as a fishing method, and work by trapping fish and sharks by their gills once they have pushed their heads through the mesh. Most of the animals caught in these nets, die.

Drumlines are a more targeted form of fishing and consist of a large, anchored float from which a single baited hook is suspended. Originally, the floats used were drums, which is where the method gets its name. Since the introduction of drumlines, the capture of non-target species in the nets has been reduced by 47,5%. This is due to the drumlines being so effective in catching (and killing) sharks.

These nets and drumlines do not form a complete barrier and sharks can swim around them – so in essence they function as a targeted fishery and target sharks. The logic behind them is essentially to reduce the number of large sharks in the vicinity of certain beaches, lowering the probability of encounters between sharks and people.

It should also be noted that there are numerous swimming beaches along the KZN coast, such as Tinley Manor, Mtunzini, Ifafa and St Lucia, (and the other three coastal provinces) that do not have nets and do not have a higher incident rate of shark attacks. The necessity of these nets is questionable. Unfortunately, the public have the incorrect impression that shark nets are in fact a solid barrier and make it safer to swim at these beaches with nets, rather than at those without. This approach is unique to KwaZulu-Natal in South Africa, with the rest of our country having figured out alternative ways of managing “us being in the ocean with sharks” without harming them. It is their home after all.

The Shark Spotters https://sharkspotters.org.za/ programme in the Western Cape is a proudly South African example of a non-lethal solution that keeps both bathers and sharks safe in a shared sea.

Not only do sharks get caught in these nets and drumlines – they are known to also entangle both non-targeted shark species and other species. For example in 2017, the protected animals that died in the nets included 18 turtles, 26 dolphins, 4 whales, 30 rays and 69 scalloped hammerhead sharks.

Some scientists have indicated that since the nets were deployed in 1952 in Durban and along the KZN coast, they have provided useful data about the status of sharks and rays. However, understanding whether the severe declines seen for many of the species is confounded by not knowing whether this is caused by the shark nets alone, or by other fisheries that target many of the species. The question is whether it is responsible to rely on dead sharks and rays for data. Is it responsible to keep these nets and drumlines in the water, and in such high numbers, or should we replace them with new modern techniques available for bather safety reassurance, while phasing in monitoring with remote video systems, and tagging sharks that do not kill sharks and other endangered species – we would argue for the latter.

TRADE

Globally, sharks and rays are caught by industrial and artisanal fleets either as directed or as secondary catch, supplying shark and ray fins to markets in Asia, while the meat of the same captured sharks is increasingly being traded along separate supply channels to meet growing demand in markets in Europe and South America.

Some sharks, especially deep-water demersal species, are targeted for their liver oil. It is estimated that between 73 and 100 million sharks are killed each year in fisheries around the world. South Africa exports shark meat predominantly to Brazil, Uruguay, Spain, Italy, South Korea and Australia, while the key importers of shark fins from South Africa are Hong Kong Special Administrative Region (SAR), Singapore, Macau SAR and Japan.

Due to their broad distribution, often migratory nature, and occurrence in a range of fisheries, regional and international co-operation is necessary to manage shark fisheries appropriately.

In recognition of this, numerous fisheries management measures have been implemented in recent years, as well as trade regulations. Since 2002, 38 shark and ray species have been provided with greater protection linked to international trade through listing in Appendix II (trade of the species is controlled) of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and the entire family Pristidae (Sawfish) is listed in CITES Appendix I (species is threatened with extinction and trade is only permitted under exceptional circumstances).

PERCEPTION

What can you do?

Support the @sharkattackcampaign www.sharkattackcampaign.co.za and get your friends and family to do the same.

Educate yourself and the people in your networks 

Host a screening of the WILDOCEANS SHARK SANCTUARY Film – email: [email protected] or [email protected] to find out how!

Join our YOUTH MOVEMENT – advocating for the increased protection of sharks and rays in South Africa – to ensure a future without extinctions and where recovery is achieved, email: [email protected]