DIVING SHARKS: BEHAVIORAL HABITS

 Text & illustrations: Steven SURINA

While there are areas in which the expertise of a situation leads to a formal conclusion, in the behavioral analyzes of terrestrial or marine animals, no infallible rule can be defined. Stemming from empirical observations, are nevertheless born from usual practices depending on the situations, which always turn out to be different. Indeed, it is not possible today to classify the acts and gestures of animals with absolute certainty. However, we can observe behavioral rules that are valid in many regions of the world, which will have to be continuously adapted according to the situation.

Some interaction codes can help any diver to decipher the attitude of sharks according to the circumstances, to learn to understand their body language in a given spatial situation.

THREE ZONES OF EVOLUTION

We will call the spatial limit of the shark the entire environment that will encompass the animal during its approach phases. For example, in the blue, the shark has no spatial limit. He can leave at any time without being bothered by anything. On a coral plateau, the spatial limit of the shark will be the substrate of the reef, which does not allow it to flee as it pleases. Near the surface, the spatial limit of the shark will be the "ceiling" created by the surface itself.

In the underwater animal kingdom, there are codes of evolution between predators and prey according to their zones of evolution.

BELOW: OBSERVATION

When an upper predator is below its prey, it is in an observation situation. It turns below the area of ​​evolution of its prey or an unknown animal / object to learn what has aroused its interest. He does not get close but collects all the information he needs to understand the intentions of the protagonist. In these phases of approach, the shark has no spatial limit, it can disappear at any time, when it wishes.

AT THE SAME LEVEL: FINE OBSERVATION

When a shark evolves at the same level as a diver, it seeks to refine its information on what has aroused its curiosity. He can then adopt several phases of approaches. Mainly based on curiosity, the animal will turn over a more or less wide area around the diver. The causes of these approaches are most generally “passive” territoriality, food or other stimulation. When an animal is stressed or uncomfortable, it can make a "forced passage" on the same zone of evolution as the diver which can sometimes be taken for aggression. Approaches of this type mainly take place in phases where the character animal flies over a spatial boundary, such as a reef or seabed. This can also occur in the blue with more fearful species.

ABOVE: TAKING TERRITORIAL CONTROL

The situations in which a shark swims above a diver are rarer. The animal must first go through the first two approach phases and the diver must stay underwater for a long time with the same specimen. It can also indicate that we are in the presence of a shark which is not afraid of the unknown by nature and that it is therefore powerful in its biotope. The flight of a shark above our heads results in a takeover of the territory. The predator becomes dominant in the area by its "supremacy" and its character. He will then decide on the approaches to come: inquisitive, passive or fearful.

SPACES OF EVOLUTION

Man feels the distance in the same way as other animals. His perception of space is dynamic because it is linked to action, to what can be accomplished in a given space. The physical boundary of our body, the skin, is not our limit compared to the surrounding world: we move, a part of the space attached to us, a sort of invisible bubble, which regulates our contact with others without us we are aware of it. These are the intimate, personal, social and public areas.

We find more or less the same spheres of evolution in sharks, with different distances depending on the species. In general, it is the shark who will decide whether or not to approach based on the signals sent by the diver. If a diver approaches a shark without being "invited" or without the shark being prepared, he can scare the animal away. The phases of approaching sharks, without any other stimulus, are long and complex. During an interaction, they necessarily take into account the different spheres with all that they imply.

FIVE TYPES OF BEHAVIOR

As we have seen above, it is impossible to establish fixed rules concerning the inhabitants of the aquatic environment. There are however in the underwater animal kingdom of the primitive behaviors related to a long evolution causing the animals to react according to the situations in different ways. They are innately programmed to intervene depending on whether it is the phases of predation, reproduction, migration and facing the unknown. The meeting of the shark and the man constitutes the phase "facing the unknown". It represents less than 1% of the various encounters he will have in his entire life as a fish.

Legend: 1 - fearful / 2- haughty / 3 - shy / 4 - curious

CRAINTIVE ATTITUDE

The shark belongs more generally to suborder predators. He does not have the status of dominant in his biotope. He is therefore fierce in nature and in unfamiliar situations he will simply observe. If it enters one of the other phases facing a predator or a diver, it will prefer to leave the area and leave the field open to the other species. He will not let himself be approached and will opt for flight rather than confrontation. These fish are extremely sensitive to stress.

ATTITUDE OF IGNORANCE

The haughty sharks who ignore us first define their axes of approach. From the beginning of the interaction, they have all the information they need to progress. They do not consider the unknown as a danger. They most often belong to the upper links of their food chain. They will pass at the level of the divers neglecting the different spaces of evolution.

SHORT ATTITUDE

Shy sharks can be both suborder predators and predators at the top of their food chain. The attitude of shy sharks results in an observant shark that does not break its internal section, therefore its social zone. He swims most often under divers or at their level while maintaining a safe distance without putting themselves in direct danger in the face of the unknown. These sharks are sensitive to stress.

CURIOUS ATTITUDE

These are sharks who immediately realize that the unknown is not a threat. They are immediately curious and there is no fearful or shy approach phase. They are most often sharks with dominant status in their biotopes. These are certainly the most moving phases of interaction. The animal comes to contact with the diver. The duration of these meetings is variable.

DOMINANT ATTITUDE

Dominants are sharks belonging to the upper levels of their food chain. As predators, the interaction will be governed by fixed rules. It will therefore be less flexible than with other species. "Potentially dangerous" sharks may adopt this behavior. They evolve in all areas of evolution, often at the level of the diver, or even above him. The diver should in no way react as a prey not to be confused with it by the shark.

Some sharks may, depending on the interactions, adopt several attitudes during the same encounter. They can also be dominant one day, and fearful the next day!

THREE TYPES OF APPROACHES

Among the approaches observed, there are now thousands of different behaviors because they are multifactorial. It is necessary to take into account the species of the shark, the depth, the experience of the divers, the attitudes of the shark,… etc. Thanks to underwater observation it is possible to detect three types of well-defined approaches: The fearful approach, the passive approach and the inquisitive approach.

The observation of these three types of approaches, allows to affirm that there are "systematic" related to the behavior of the shark, that of the diver, to the zone and to the space of evolution of each one. Again, a complex multifactorial equation will determine the shark's approach to the diver, which is why there is no set rule.

Through these systematic, present in the three main groups of approaches, we will always find successively: the passage, the lateral approach, the frontal approach, the crossed approach, the approach "blind spot", the vertical approach , the patrol, the face to face and the inquisitive round. There are probably hundreds of others, but the most commonly observed by divers with the 30 or so observable species are these.

Sharks are so different, there is such a diversity of attitudes, behaviors and lifestyles that one can simply say "I saw a shark". But there is better. If we put all the chances on his side, we will one day have the joy of being able to say "I dipped with a shark".

In a future article, Steven will discuss the rules of shark-diver interaction.

Steven Surina

Steven Surina is a diving instructor in the Red Sea. In this capacity, for a decade, he has accompanied cruises along the Egyptian, Sudanese and Eritrean coasts. He worked in partnership with the Italian publishing house “Magenes Editoriale” on the project of a collection of dive sites all over the Egyptian Red Sea as an author and illustrator. He wrote a dissertation on the behavior of oceanic sharks in 2008 and had interactive booklets on the protection and preservation of sharks distributed to Egyptian schools.

View the profile of Steven SURINA