Shark feeding and its consequences

Attempt at an explanation

After the scary video scenes of the shark accident off Hurghada, another scary report went around the world these days. Last week, a woman was injured by a nurse shark while snorkelling at the famous Embudu Express dive site off the Maldives island of the same name, and the rumour mill is already boiling. As with the shark accident in Hurghada, direct or indirect shark feeding is said to be the cause. At least that is what is being said behind closed doors.

Report by Gerhard Wegner

Are shark feedings really the reason for all these shark attacks?
It is high time to analyse the consequences of shark feeding or to attempt an objective analysis. The limitations come from one of the best-known shark researchers. Dr Samuel Gruber once put it in a nutshell in a conversation with me. He said: no shark accident in this world can be explained. The reasons: There are simply too few accidents and far too many influencing factors.

He is certainly right, but we humans and especially the media need explanations. As simple and straightforward as possible. That is what is currently happening. Killer sharks attracted by food or sharks starved because of overfishing are a simple explanation. Likewise, the publicly communicated hunt for the killer shark and the display of the killed animal is a simple solution for the local tourists.

Simple - but not necessarily true. And here we are in the middle of the problem. How to explain a shark accident when, according to Doc Gruber, you simply do not know how to do it?

This was the problem Christine Gstöttner and I faced when we set out to write BLIND DATES (Download Link for Chapter 6 (30MB)), a book about shark encounters and the reasons for shark accidents. Our motivation for the book was the same as for this article. Explaining shark accidents is basically about protecting the sharks. The reason: no one protects a killer. The task I had already set myself with the founding of SHARKPROJECT was thus clear: to straighten out the image of the shark in the public eye. In other words, to turn a man-eating killer into a completely normal predator.

Not easy when there are shark accidents with fatal consequences. All the more important to somehow understand the reasons for these rare accidents. It was clear that we could not rely on science to do this. So we did what mankind has been doing since time immemorial with great success when confronted with the unknown. Which animals and situations are dangerous for us and which plants and berries are poisonous or edible, our ancestors learned not through science but through experience. Learning by doing…

It is true that Christine and I brought a lot of shark know-how with us (over 4,000 dives for me, including 1,500 only with or because of the sharks, and Christine with a comparable number), but that did not make us shark gurus who know everything, or think they do... Unfortunately, there are far too many of the latter. For the book, it was important to have a broad knowledge base so as not to be pushed into the corner of self-proclaimed gurus. For this project we brought 25 international shark experts (dive guides, scientists, researchers, photographers and filmmakers) on board. Based on the experience of more than 35,000 shark encounters together, we then tried to find conclusive reasons for shark accidents in the book BLIND DATES.

                                                                     Download Link for Chapter 6 (30MB)

At first, Christine and I didn't know if the project would succeed, but we were soon gripped by enthusiasm when we realised how the different experiences complemented and interlocked with each other and produced clear, unambiguous empirical values.

From an early stage, we all agreed that food in the water - direct or indirect food - is a key factor in shark accidents.

Finding 1: As predators, sharks are predominantly food-oriented. When they are not panting after the opposite sex, they are on the lookout for food. Whether it's just the smell of food, sounds that sound like food, or a tasty morsel in the water - all of these things attract them over long distances, turn a rather shy animal into a very curious one, and it changes both the behaviour of individual sharks and the group dynamics.

Finding 2: However, there are clear differences in behaviour between open and closed feeding. What I mean by this is impressively demonstrated by the following pictures.

A shark feeding with a bait basket filled with pieces of fish. A popular method for shark feeding. The smell magically attracts sharks. Nevertheless, there is no rush. They curiously circle the basket and keep a careful distance from the divers.

The same situation a few minutes later. The guide wanted to give the divers "action" and tipped out the basket. The pieces of fish scattered in the water and the behaviour of the sharks suddenly changed. A flurry of activity broke out, they shot across the water, jostling each other and divers who dared to come too close. The situation became unpredictable.

So are shark feedings now the trigger for shark accidents?
A clear no. Food in the water, including open food, is indeed a central stimulant, but it only increases the risk of a close shark encounter. Only when additional factors are added does it become dangerous.

These additional casualty factors are:

The type of shark
There are over 500 species of shark and only a few can be dangerous to humans at all because of their size, teeth and behaviour. Tiger sharks, bull sharks, great white sharks, for example, usually hunt in shallow shore waters, they are large and have knife teeth. No wonder that these three shark species are also involved in most accidents.

Irritation of the senses
This includes anything that affects its senses, i.e. poor visibility, lots of noises in the water, lots of different smells or electrical voltages, such as during a thunderstorm.

Competition
Individual sharks behave differently than a group of sharks. The competition factor, i.e. who owns the food, is an important factor here in losing shyness and caution.

Personality of the animal
Those who have pets of their own know that dogs are not all the same, cats are not all the same, even canaries have different personalities. Some animals are more curious than others and some are even real bullies. This is just as true for sharks.

Conditioning
This means that sharks can also get used to humans and even lose their original shyness. This happens, among other things, in areas where humans and sharks regularly meet, for example, in shark hunting grounds that they share with beach visitors or water sports enthusiasts.

No respect
The difference between the dangerous appearance of sharks and their harmlessness to humans has led to real shark tourism in many areas. Recklessness and irresponsible shark feeding are unfortunately common.

Simple conclusion: the more accident factors add up, the higher the risk of a mix-up, a shark accident.
With this thesis, one could theoretically explain most shark accidents somehow and also assess the risk of shark feeding. It is clear that food in the water is the strongest stimulus and amplifies all other factors. But why then do some accidents only involve jostling with a possible test bite and others have multiple, serious bites documented? The secret lies in the motivation of the shark to attack a human. Our experts speak here of three to four scenarios. According to the mode the shark is in, the type and severity of the shark attack differs.

The shark is hunting.
This is characterised by a fast, hard attack with violent bites to weaken the prey. This is the rarest type of shark attack on a human. And it is always a case of mistaken identity. The triggers here are mainly typical stimulants that arouse a shark's hunting instinct, such as open food in the water or frantic movements that make the shark think it is an injured fish.

Hit-and-Run bites
Again, food is involved. Smells or sounds that promise food to the shark without arousing the hunting instinct. The shark is curious, but will act very cautiously and cautiously because it does not know what to expect at the end of the smell. The thesis of added accident factors fits perfectly here. Each additional accident factor will make him even more curious. He may jostle or even take a test bite, a so called Hit-and-Run bite. This sounds worse than it is. A test bite is not a real bite.

Since a shark has no hands, it will first try to make sense of the unknown object with all its senses. At the end of such an investigation there is jostling and only if he is still unsure afterwards does a test or palate bite occur. Here he presses the upper and lower jaws against the object without actually biting. This is where its taste buds in the palate come into play. A curious shark probing is the most common cause of accidents. However, real bites occur only in rare cases. In 99.9% of all cases, the shark turns away beforehand.

The shark is under stress
Such a scenario arises when other sharks are involved. Due to the competitive pressure, the sharks are excited and shoot through the water in search of prey. Stress can lead to jostling and biting. A lack of respect for the animals and a lack of precautionary measures are the risks caused by humans themselves.

The shark defends itself
Punches and kicks do not necessarily repel a shark. Sharks can also perceive pushing and shoving away as an attack and defend themselves with bites.

With all this knowledge, can we now explain the shark accident off Hurghada?
Let's sort out what we know. Thanks to the know-how of our experts, we know quite a lot about shark behaviour. And the details? There is even a film of the accident off Hurghada and several eyewitness accounts. We know the type of shark involved and a bit of the history. There are almost no other shark accidents with more facts. So let's give it a try.

An attempt at an explanation
A tiger shark approaches a bathing beach on its normal feeding patrol. The beach patrol notices the fin and sounds the shark alarm. In a state of sheer panic, the bathers leave the water. The frantic sounds of their flight arouse the shark's curiosity and it swims to the beach. There is only one swimmer left in the water. The alarm and the horrified cries of the other bathers also now send him into a panic. As fast as he can, he tries to reach the shore. Its frantic escape movements are another attraction for the tiger shark. Movements under water produce sounds for sharks and the panicked swimming produces exactly the same frequencies as injured fish. In addition, there is the flight. Another indication of possible prey. But it is still undecided, circles around the swimmer bumps it, even lifts it briefly out of the water. Panic-stricken, the swimmer now kicks around. In hunting and/or defence mode, the shark bites several times, injuring an artery. When the coast guard arrives shortly afterwards, they can only recover the swimmer's body. This or something similar could have happened. Or maybe not! Maybe it was completely different.
For now I have fallen into my self-imposed trap and, with my half-knowledge, have put myself in a guru state and tried to explain logically something about whose background I know far too little.

And with that, we should leave it alone. With an average of only 60-80 so-called shark attacks with 6-10 deaths per year worldwide, any explanation is basically superfluous anyway. One thing is certain, humans are not part of the sharks' food spectrum and the few attacks per year are extremely rare accidents.