It is time to reconcile with the Sharks.
The vast majority of life forms on Earth are dependents on other forms of life to some extend – and this is especially true with more evolved life form. One interesting thing for biologists to observe and describes are collaborations in Nature. Those collaborations sometimes creates strong links, such as the one between clown fish and anemones (here mostly for protection), or closer to us, people and dogs (in this case for several reasons, one being hunting and food).
« Cognitive » animals evolved with the ability to learn if a newly encountered species is « prey », « predator », « collaborator » (for example the cleaner wrasse for other fish), « hunting partner » (for example goatfish and trevally), « indifferent, to ignore » (a turtle for a pipefish, a shrimp for a seahorse), or a species they can benefit from (for example for warnings of an incoming predator, or feed on leftovers). We have given names to describe some of those relations, such as Symbiosis or Commensalism.
Some of this learning takes generations, some of it works using teaching from the parents (Killer whales are a great example here). Some of it happens a lot faster (try hitting one dog and feeding another and see: the first dog will identify you as dangerous, to escape from, the second one as a friend he can benefit from). Another example are sea turtles : in areas where they are hunted by people they escape as fast as possible as soon as they see someone. In area where they aren’t, you could easily touch them. Same species, different experiences.
This learning process is especially developed in a rich marine environment such as tropical coral reef. This comes from the high biodiversity, high movement capacity of some species, and complex cycles leading each species to meet a lot of other species regularly, and new ones often. Again, part of this process is passed between generations, but for long-living, moving animals, the process of learning about a new species during a lifetime is particularly developed: it happens within a few experiences, sometimes as little as one. Tiger sharks are a great example and have shown being able to learn to eat completely new type of preys such as sea birds, and to remember where and when (in the year) they have the best chances to catch them. A great author to read to learn more about animal cognition is Frans De Waal who wrote a few great books, with many mind-blowing examples.
It does make a lot of sense indeed, that a long living moving animal would be able to learn what is dangerous, what is prey, and which other species he could benefit from. Nature would be poorly efficient without it. This is one of the reason why being smart matters, and collaborative animals and groups have shown to be more competitive overall.
This process has been used by people in interesting ways, for example with dogs or horses. I believe it could be used again.
Sharks caused conflicting situations in the recent years when biting people, occasionally resulting in death (bleeding out or drowning) of the person bitten. The extremely rare cases (a few every year, worldwide) only come from a few shark species (around 1%). I will talk here specifically about Bull sharks, as they are the one resulting in the most deadly bites, but this apply in a similar way to other species.
Several actions have been taken in the last few decades to try to lower the risks of shark accidents. But, after decades of trying, there are still no solutions that seems to even remotely reduce the risks (examples in Hawaii, Australia, La Réunion, the U.S.)
The problems are compelling :
– We haven’t find any ways to reduce the chances, apart from stopping people from going in the water.
– The unsuccessful solutions used so far have come with a colossal cost, not only in money (millions of $) but in ecosystem damage (thousands of sharks killed, sometimes turtles, dolphins, other fish…) and the after-effect of the keystone species loss that is impossible to measure, but real.
We are in 2019. Surely we can come up with clever, efficient ways to lower the shark bite risk with minimal cost and damage ?
I know today, with the knowledge and experience we have gathered in the last decade, we can.
When a shark bite a swimmer or a surfer, it is usually because one or several of the following:
1- The shark is hungry and is not able to find its natural food.
2- The shark is adventuring in an area where they normally don’t go (for example, because of too much human activity that repels them) because it doesn’t know where to find food anymore, potentially due to ecosystem loss, overfishing, habitat destruction.
3- The shark either 3a-make a mistake bitting a human/surf thinking it is something else, or 3b- decide to attack a new type of prey knowing it is not its usual one.
Together with points 1, 2 and 3, there are additional circumstances:
4- The area in which the bite occurs has particular conditions that attract sharks : murky waters, sunset or sunrise, specific smells (rivers carrying organic material, overflowing or release of water-treatment, fishing or fishing waste…).
5- The shark involved has a naturally bold personality.
There could be additional, anecdotic factors that increase the risks. A couple of example are the color of the suit / surfboard, or the sound produced by a riding surfboard could influence the trigger of a bite.
Finally, there is random bad luck.
So what happens just before a bite ?
When a bite is « calculated » (not just a « reflex-bite », if there is such a thing) there is a process that the shark go through.
The only way for sharks to « test » if something new is to be put in the « prey » box is simply to make moves on it and see how it react. If it swims away fast, it is probably a prey (just like if you start running in front of a dog !). We could then imagine what the speed of a surfer on a wave could trigger. If the investigated doesn’t react, sharks either leave after the better-look they just took, or get closer over time until they are able to bump (or bite) into it and get a « feeling » of what it is and how it reacts. If, at the moment just before the bump (or bite), the investigated’s body language suggest it could be a prey suddenly getting ready to try to escape, the shark might then continue all the way to a bite. Most times, a movement before a bump/bite will simply scare the shark away. In rare cases, the sharks might be in a specific combination of the above-mentioned points 1 to 5 that result in a bite.
So where does that leave us ? We have a good idea of the conditions that makes the chances of a bite higher, and we have a good idea of what happens just before a bite, at least in the vast majority of cases. We also know people have been spearfishing, diving, free-diving, feeding sharks with close to 0 incidents (0 when well done). And we know we can “train” animals so that they identify us a “not-a-prey”. Surely with all those information we can design a plan !
Is there a way we can influence or use the points 1 to 5 ? Is there even a way where we can influence the chances that an random encounter with a shark result in the shark identifying the person as NOT a prey ?
There is a way to influence all that. All it takes is a few skilled people, a bit of money and the support from politics and sea users.
More good news ?
It will eventually generate money to make the process sustainable, regenerate ecosystem and biodiversity, generate ecosystem services, increase scientific knowledge, incubates/catalyses additional science and conservation projects, and adds prestige to the area and actors.
What are we waiting for ?
The political support, the legal framework to make the right thing the right way.