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Local fishers contribute towards landmark South African shark study

Posted on 13 July 2020

Small-scale fishers in the Kogelberg helped to gather and analyse data for a study of South Africa's smaller shark species.

In a first for local fishers, the fishing community of the Kogelberg, supported by WWF South Africa, has contributed towards the recent publication of two scientific papers on the status and diversity of smaller endemic shark species in South African waters.

The stretch of coastline where the study was done, including the coastal towns of Betty’s Bay, Pringle Bay, Kleinmond and Hermanus, is a hotspot of marine biodiversity and is home to over 60 species of sharks and rays.

The researchers found that South Africa’s unique catsharks, such as pyjama and puffadder sharks, along with the larger seven-gill shark, have a strong affinity to habitats used by many marine species, making them perfect “umbrella species” to focus conservation efforts.

Because the biodiversity of Betty’s Bay is valuable to both biologists and fishers, this research embraced the skills and knowledge of the local Kogelberg fishing community to conduct the science. WWF has been working alongside fisher communities in Kleinmond, Betty’s Bay and Pringle Bay since 2012.

Since 2017, fishers have been helping to deploy baited remote underwater video systems (BRUVs), a special non-destructive technique used around the world to study marine predators, both inside and outside the Betty’s Bay marine protected area (MPA).

These deployments, along with BRUVs deployed in the Walker Bay area by the South African Shark Conservancy, formed the basis of this research.

Attached to the BRUVs camera on a meter-long metal rig, oily fish bait attracts both scavengers and predators to be filmed on the ocean floor, allowing scientists to measure their abundance and diversity while also discovering the favourite habitats of these marine creatures.

Capturing these videos also takes a lot of work. Camera rigs must be set up with bait, boats need to navigate to the exact right spot in the ocean, heavy metal rigs and ropes must be deployed and then delicately retrieved, and hours of video footage must be analysed with careful eyes.

Now, the fruit of this research has been published in two scientific papers, co-authored by Geoffrey J. Osgood, Meaghen E. McCord and Julia K. Baum, in the African Journal of Marine Science and PLOS One.

Lead author Geoffrey Osgood commented: “Luckily for the shark scientists, the Kogelberg fishers stepped up to the task to help with every facet of BRUVs research in Betty’s Bay. Beyond the physical struggle of pulling dozens of BRUVs rigs off the ocean floor, the scientific data collection was also packaged with excruciating monotony. The fishers showed their dedication to science as some community members viewed hours and hours of video footage to count and identify 70 different species of marine life.

“Using BRUVs not only limits harm to the marine life that the scientists wish to study, it creates opportunities for people of diverse backgrounds to engage in data gathering and science. Both of these studies show that conservation need not conflict with the needs and livelihoods of local fishers. In fact, the best insights come from working together, and for their contributions to the conservation of South Africa’s world-renowned biodiversity, the Kogelberg fishers must take a bow.”

What the researchers found

While larger sharks (like copper or gully sharks) were largely missing from the footage – possibly reflecting historical fisheries targeting these species – small, endemic shark species (such as pyjama and puffadder sharks) were thriving, especially in kelp and reef habitats.

However, these smaller sharks, which are often treated as nuisances by fishers, still face threats, and are thus in need of greater conservation attention. The BRUV results show that even the small marine protected area of Betty’s Bay can offer local protection to these smaller sharks and the patches of reef they call home.

While South Africa’s endemic catsharks may not currently be threatened, their abundance in the region is supported by the quality of habitat located in Betty’s Bay, indicating even small MPAs can play a role in protecting coastal ecosystems and endemic species.

The BRUVs provided deep insights into which habitats need protecting in such MPAs, discovering that a few sharks and rays prefer seemingly barren sandy and muddy sites over complex reefs.

They also revealed myriad other marine species share their habitat with sharks, such as red roman and red stumpnose, giving hope that the conservation of habitats loved by sharks will also spread an “umbrella” of protection to other species in South African waters.

As great white sharks continue to disappear along this coast (no great whites were detected on the BRUVs footage), the larger seven-gill shark will be key to promoting marine conservation in the Kogelberg and beyond as it moves into the great white’s old haunts.

Should fishing pressure or habitat degradation intensify, these “umbrella” sharks could be used to promote MPAs for the conservation of a variety of the endemic species that make South African oceans unique.

The fishers who contributed towards this research are: Amos Hendricks, Angelo Jansen (data analyst), Desmond Makka (boat owner and rig maker), Dirk Andreas (fisher and skipper), Gabriel Krewitz (skipper), Marceline Barry (data analyst), Mbuyiselo Makibi, Melvin Jooste, Nicklaas Jansen, Nicholas Taylor, Petrus April, Randolph De Bruyn, Ray Williams and Uwe Dörle.

Pyjama sharks are endemic to South African coastal waters.

Local fishers contribute towards landmark South African shark study

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