Shark attacks can be absolutely devastating, not only to the poor victim and their families, but also to the wider community who suffer grief and fear after such an horrific event. In the past, beach nets were to used to try to prevent such incidents, but these actually kill enormous amounts of sharks (and other sealife, including turtles, dolphins and birds), so they are very unsustainable. Engineers have been attempting to build electrical and chemical shark repellents, with mixed results, for many years, but a team in South Africa may have come up with an even simpler, more cost-effective and (most importantly) incredibly effective method to protect their ocean users from potential dangerous sharks. They implemented a program called the Shark Spotters. So who are the Shark Spotters? How does this work? And does it ensure that people can enjoy the ocean without too mush risk from sharks?
I See You!
The Shark Spotters program in South Africa has become recognised as a world-renowned flagship for beach safety in a shark-rich area. South Africa is blessed with many different species of sharks, namely the great white (Carcharodon carcharias) and tiger shaks (Galeocerdo cuvier). In order to circumvent the need for destructive nets and drum lines, whilst still protecting ocean-users from potentially dangerous sharks, the Shark Spotters have implemented a system of ocean surveillance and alarms in order to minimise human-shark conflict (Kock et al, 2012; Engelbrecht et al, 2017).
Sound the Alarm!
The scheme involves a highly trained team of scientists and shark spotters patrolling popular South African bather beaches from high-ground, in order to spot any sharks in the water (Kock et al, 2012; Engelbrecht et al, 2017).
When the Shark Spotters see a shark from their vantage point, they will identify the species and observe the behaviour. In the event that the shark is deemed to be a threat (when a shark comes too close to bathers/surfers or appears to be acting in an aggressive or predatory manner) the Shark Spotters sound a loud alarm, signalling for everyone on the beach to exit the water. When the shark vacates the area and it is considered safe again, beach-users are allowed to return to the ocean (Kock et al, 2012).
A colour-coded warning flag is also displayed on the beach to communicate the shark conditions to beach-users. A green flag signifies that spotting conditions are good (clear weather, good water visibility) and no sharks have been seen. A black flag means that spotting conditions are poor, so they cannot stay with any certainty whether sharks are present of not. A red flag signifies that a shark has recently been seen and ocean-users should be cautious. Finally, a white flag, accompanied by a siren, means that a shark has been sighted and all bathers must exit the water for their own safety (Engelbrecht et al, 2017).
Does It Work!?
After several years of the Shark Spotters system being in place, scientists assessed how well it was working. They reported that, at first people were a little mistrustful and often scared off by the sounding of the alarm, but after some years, people began to place their trust in the Shark Spotters team and would wait patiently on the sand until the water was declared safe again. They concluded that, over time, the public began to perceive the risk from sharks differently. This highlights that these kinds of initiatives can be very valuable for public education, changing perceptions of sharks and for reducing shark attacks (Kock et al, 2012).
Recently, researchers sought to re-evaluate the efficacy of the scheme, by assessing how many negative human-shark interactions had occurred since the plan was initiated. Basically, are the Shark Spotters stopping shark attacks?
To evaluate this, they identified how often sharks and humans were close together in the water (what they called 'overlap') at Fish Hoek and Muizenberg beaches between 2006 and 2014. They also calculated which groups of ocean-users were present (swimmers, surfers, kayakers...), to see if certain groups of people were more at risk of shark attack than others (Engelbrecht et al, 2017).
They discovered that the Shark Spotters program had a significant effect on how many people entered the water; when the siren was sounded and white flag waved, the majority of all ocean-users (including swimmers, surfers and paddlers) all exited the water. When the red flag was displayed (meaning a shark had been seen recently), water usage was also reduced. This shows that the Shark Spotters system vastly decreased the overlap of water-use and therefore, reduced the risk of shark attacks (Engelbrecht et al, 2017).
Practice Makes Perfect
The study was also valuable for aiding the Shark Spotters team to improve their methods. They found that the busy summer months (when many people spent time in the water) coincided with increased white shark abundance along the South African coastline. As this meant there would be a heightened risk of shark attack during this period, they stated Shark Spotters would increase the effort devoted to spotting sharks during this time; especially in the month of September, when the highest number of sharks attacks have occurred in the past (Engelbrecht et al, 2017).
Whilst they felt that the program was beneficial for reducing shark attacks in the area, the researchers did express some concern that more education might be needed in order ensure people fully understand the risks posed by sharks (Engelbrecht et al, 2017).
They noticed that ocean-use increased quite dramatically after the siren ended and the flag was changed from white to red, suggesting that people believed the threat was completely over. They also mentioned that despite warnings, some ocean-users remained in the water, even during a siren (Engelbrecht et al, 2017).
They gave an example of when a shark attack occurred at Fish Hoek in 2011, when the victim chose to enter the water, despite a white flag being flown and the alarm sounding. They suggested a change to the system might be necessary or a more extensive education program, but also noted that, at the end of the day, the decision to exit the water is personal to every ocean user and each person must make their own decision... Basically, "you have been warned" (Engelbrecht et al, 2017).
Yet, they also stated that, despite a large amount of overlap, with sharks and humans sharing the coastal waters of South Africa quite frequently, the number of shark attacks were incredibly low! Less than one unprovoked attack on a human was reported in the area each year during the study period. Therefore, the researchers emphasised that great white sharks were not actively targeting water users for prey. So, if you are ever enjoying the ocean in South Africa, it is extremely unlikely that you would be a victim of shark attack... and you can take comfort knowing that the Shark Spotters team will be there helping to keep you safe!
To learn more about other shark protection measures, you can check out my other articles o shark attacks.
References
Engelbrecht T, Kock A, Waries S & O'Rianin MJ (2017). Shark Spotters: Successfully reducing spatial overlap between white sharks (Carcharodon carcharias) and recreational water users in False Bay, South Africa. PLoS One, 12:9, e0185335. Access online.
Kock A, Titley S, Petersen W, Sirweyiya M, Tsotsobe S, Colenbrander D, Gold H & Oelofse G (2012). Shark spotters: A pioneering shark safety program in Cape Town, South Africa. (Ed.). Global Perspectives on the Biology and Life History of the Great White Shark, Taylor & Francis, New York, p. 447 - 465.
By Sophie A. Maycock for SharkSpeak
fantastic idea