Shark Spotters report: White shark caught in experimental whelk fishing gear in Fish Hoek bay

At approximately 10.30 am on 11 March, Shark Spotters research manager, Alison Kock, was alerted by whelk fishermen operating in Fish Hoek bay that they had found a large white shark entangled in their fishing gear. By all accounts the animal was dead when found by the fishermen and as such any belief that the animal could have been released is false. Alison notified the relevant authorities from the Department of Agriculture, Forestry and Fisheries (DAFF) and the Department of Environment Affairs (DEA) to ensure that all compliance protocols were adhered to with it being a protected species and assisted with arrangements to get the shark transported to shore in a whole state. The shark was towed to Simonstown harbour where the SA Navy, DEA and City of Cape Town’s Disaster Management teams were able to haul it out with a crane and transfer it onto a flatbed truck. The shark was taken to DEA’s storage facilities where it will be frozen until a necropsy can be done at a later stage. The shark was a large female measuring 4.3 m total length and weighing in at 886 kg. We had a look through our photographic catalogue of about 260 sharks to see if we could find a match, but so far we haven’t and have forwarded the ID photograph to colleagues in other areas.

According to fisheries scientists and the permit holder the experimental permit was issued by DAFF to explore the sustainability and practicality of whelk fishing in the area. ‘Whelk’ is the common name applied to marine gastropods, also known as sea snails. The fishing gear consists of hoop nets (approximately 1 meter in diameter) which are baited with fish like sardines and then deployed on the sea floor. The whelks, being scavengers, then follow the scent trail into the net where they are caught. The process is similar to crayfishing using crayfish nets. The difference with this system is that up to 15 hoop nets are connected together. The hoop nets are attached to surface marker buoys by rope and weighted with a 10 kg weight. The fishing gear is set overnight and in the morning the whelks are harvested from the nets. The shark appears to have become entangled in the ropes connected to the hoop net which form a bridle (allowing for stability when lifting the net so the whelks don’t fall out) and another line is connected to the bridle and surface marker buoy. The design that was used had excess rope and a large enough area under the bridle near the opening of the pot which allowed the shark to be able to get its head through while investigating it. What appears to have happened is that the shark became entangled in the lines and at this stage consensus with authorities and scientists is that it likely suffocated to death.

The experimental fishery first came to Shark Spotters and public attention about three weeks ago when the gear was deployed in Fish Hoek. Since that time the Spotters have recorded shark activity we consider normal for this time of year in Fish Hoek bay, which is similar to what we have recorded at Muizenberg during the same time period, and in Fish Hoek before the whelk fishing gear was deployed. We have not recorded any significant increase in shark sightings since the nets were deployed. The bait inside the hoops is not enough to attract a shark from hundreds of meters away, but is enough to attract a shark swimming in the immediate area. Given that white sharks, as apex predators are naturally very curious and their investigatory behaviour is well documented, the sharks would more than likely be attracted to the gear irrespective of what was inside.

This is undoubtedly a great loss of such a magnificent and rare animal and therefore the priority needs to be to ensure this doesn’t happen again. We formally asked the authorities and permit holder to investigate the matter and offered our assistance to them regards the fishing gear, its deployment and advice on areas of high shark activity that should be avoided. Earlier today we were invited by the permit holder to meet with him and the fishermen and DAFF authorities to discuss the way forward. It was clear that no-one wanted to see this happen again. The immediate steps that are to be taken following this meeting was to lift up all their gear, which the fishermen and authorities set off to do after the meeting, and then to make modifications to reduce the excess line near the opening of the pot to prevent a shark or another marine animal from sticking its head through or getting inside the net. Furthermore, the fishermen have decided not to continue working in Fish Hoek bay, and will be liaising with authorities and ourselves to avoid areas and times of high white shark activity.