Smart Technologies are Reimagining How Humans and Sharks Interact
By Darcie Anderson
Location: Scotland
Darcie Anderson is in her third year studying Marine Science with Oceanography and Robotics at the Scottish Association for Marine Science. In her free time she advocates for the ocean as a part of the World Ocean Day Youth Advisory Council, the Plastic Oceans UK Youth Network, and in her work with AYUDH Europe.
Sharks are charismatic creatures living in oceans around the world, from under the ice sheets of the arctic ocean to the tropical waters of the Great Barrier Reef. They are very important for ecosystems worldwide, and by extension provide economic benefits to humans, by managing fish populations and drawing tourists to coastal regions.
Unfortunately, humans also tend to be very scared of shark attacks, despite them being very unlikely, with only 57 attacks and 10 fatalities worldwide. The fear largely comes from sensationalist media coverage, disproportionately reporting on non-fatal shark attacks and using fear laden language. As a result of this fear, some governments in regions with higher risk of shark attacks have implemented shark control or beach safety programs.
The difference between these terms is important, but subtle. Shark control focuses on reducing the shark population, based on the assumption that a smaller population will result in lower risk of shark attack, often branded as a cull. Beach safety focuses on keeping humans safe, and generally uses a more evidence-based approach- this means limiting interactions with sharks to only the extent necessary, such that it reduces risk of attack.
Currently, there are three shark control/beach safety programs in Australia: in Queensland, New South Wales and Western Australia. There are three other programs internationally, in Recife Brazil, Kwa-Zulu Natal South Africa and Reunion island, a French overseas territory in the Indian ocean. These programs vary greatly. Queensland has an almost entirely lethal program, New South Wales is largely lethal with some aerial patrols, and Western Australia is largely non-lethal, with only one minimally lethal method used. The programs in New South Wales and Queensland have been ongoing since 1937 and 1962 respectively, making them the longest running marine cull in history, and the second longest running cull in total. (Dudley, 1997)
The two main shark control methods are shark nets and drumlines. It is a common misconception that nets are a barrier which prevent sharks from entering the beach. However, this is not their purpose, to the extent that 48% of sharks trapped are caught as they are swimming away from the beach. They are gill nets, like those used in commercial fisheries, designed to entangle and kill animals. These programs sadly catch sharks, dolphins, manta rays, turtles, dugongs, and other marine animals, many of which are endangered, reducing already struggling populations. One of the most heart-breaking cases of bycatch, accidental capture of non-target animals, is humpback whales, several of which are caught in these nets annually as they migrate between their tropical and Antarctic feeding grounds. Thankfully, most humpback whales caught in nets get released, however scientists have expressed worry over their long-term health and survival, especially of entangled calves caught in the nets for several hours.
AAP Image/Sea Shepherd Australia
The other method used for shark control is drumlines, baited hooks placed 500m off beaches, which have lower bycatch than nets, however, still focus on reducing populations, an approach supported by minimal scientific evidence, which ignores the benefits of a healthy shark population. Scientists in Reunion island have adapted the drumline in response to their disproportionately high rate of shark attacks, with the public desire for conservation-based approaches. Their solution was the SMART drumline, which sends a notification to local authorities once an animal is caught, so that smaller animals can be released, and large target sharks can be relocated offshore. Although this method can result in bycatch and mortalities, the rates are far lower than alternatives, and the capture of animals allows for data to be collected and tags added, so there is broad support for SMART drumlines amongst many scientists and constituents. SMART drumlines would however be considered a beach safety method, as the focus is on keeping people safe, not reducing shark populations.
Beach safety methods are generally recent developments, so not all the data is available on how efficient various methods are, however they appear to overall provide better results, with some well tested methods ready to be widely implemented.
Aerial monitoring
Aerial monitoring is a key method in various shark control programs, where lifeguards can evacuate the beach when sharks and other hazards, such as rip tides, are sighted. In New South Wales and Queensland, aerial monitoring from observers in light aircraft has been ongoing for decades, but this is expensive, provides limited coverage and recent data suggests only 12.5-17.1% accurate (Robins 2014)
Some programs have begun to use drones to monitor sharks on specific beaches, which increases accuracy to 38% of sharks sighted. Scientists are now working to make drones and other unmanned aerial vehicles more efficient at sighting sharks using artificial intelligence.
Automatic detection algorithms using artificial intelligence have been developed to analyse video feeds from unmanned aerial vehicles which have produced results of over 90% of sharks sighted in some cases. Drones are by far the most common UAV used in shark monitoring, however Project AIRSHIP has also used blimps for beach monitoring with equally strong results. In fact, there are some benefits of blimps over drones, especially on smaller beaches, as they are less expensive, can remain airborne all day (rather than 30-60 minute drone flights) and provide less noise disturbance to beach users and wildlife alike. It is important to note however that far less work has been done with blimps than drones, and there are some negatives, such as the large storage space required, not being able to fly to, and hover over, a potential hazard, and the area of video coverage by blimps being lower.
The combination of technologies for this purpose greatly increases the efficacy of these bather protection programs. The team behind project AIRSHIP worked with the SharkMate app to allow people to be alerted to potential hazards when they are on the beach, or even in the water, for people with the app downloaded to their smart watches. This allows for faster evacuation, and the app also allows for a swimmer or surfer to alert lifeguards if they are in distress and require evacuation for any purpose.
Another study proposed using an autonomous network of drones to both detect and deter sharks from the beach. The detection process works similarly to other projects described above, however when a shark is detected, in addition to alerting lifeguards, operator drones move towards the shark to deploy electrical deterrents and move them away from the beach. Electrical deterrents have varying accuracy, however those using the technology of Ocean Guardian’s SharkShield are efficient at deterring sharks with the correct configuration. These electrical deterrents do not hurt the sharks, but rather play into their electrosensory capabilities in their ampullae of Lorenzini, which is used to help them find prey. The use of drones in this way to deploy electrical deterrents is still theoretical, however it points to the possible integration of various shark deterring and beach protection technologies already shown to be effective. Despite showing great promise, these integrative methods need further study and investment before they are ready to be implemented as beach protection measures.
Features impacting visibility, such as turbidity and glare, limit aerial sighting to the top few meters below the surface, and battery life can limit how continuous coverage of beaches is, so an integrated approach with aerial monitoring, personal deterrents and beach-wide shark deterrents is the best strategy to limit negative interactions with sharks and people.
These modern monitoring methods reduce the risk of shark attacks, but also allow lifeguards to spot more common threats to beach users, such as rip tides. Algorithms can be trained to spot these features, which if developed and implemented, could have a major impact on beach safety. Major increases in shark attack survival are due to the work of lifeguards and healthcare workers, and the speed at which they attend to victims, so although these technologies play an important role in beach safety, lifeguarding jobs should be protected for their vital role in protecting beach users.
The current, widely used shark control methods are not working as they should, damaging ecosystems in the process, but we have better options available to us now, which will help prevent attacks and aid lifeguards in their essential roles in keeping beach users safe. The use of unmanned aerial vehicles are cheaper, and perform better than manned aerial patrols, and when used with AI automatic detection algorithms, can spot over 90% of sharks.