Over the last ten years, it's a fact, the diving shark intensely democratized. Thus, today, it is possible to immerse yourself in the company of different sharks. Among the species with which humans can dive and interact, there are Apex predators, or, in French, super-predators. These predators include the five potentially dangerous species for humans, namely the White shark (Carcharodon carcharias), the tiger shark (cuvier galeopig), the bulldog shark (Carcharhinus leucas), the oceanic shark (Carcharhinus longimanus) and the blue mole shark (Isurus oxyrinchus).
Of all the dives, those with Bulldogs sharks are the easiest to achieve. Indeed, the meeting sites with these sharks are more accessible. They are both near the coast and in shallow waters. This reasonable depth therefore allows all divers, even novices, to experience the thrill.
This great thrill rests largely on the bad reputation of this shark, in particular. Indeed, the bulldog is considered as shark having most often bitten or even killed the man because its areas of evolution are close to the areas of seaside activities.
Paradoxically, in scuba diving, without food attraction, this shark remains very distant. Prudent and timid, he often prefers fleeing rather than attempting a short distance approach.
The best sites offering optimal conditions for observing the bulldog shark there are three of them: Playa Del Carmen Mexico, Ponta Do Ouro in Mozambique et Beqa Lagoon in Fiji.
In this file, we will more particularly detail the two most accessible sites, both geographically and financially: Playa Del Carmen et Ponta do ouro. Before going into the heart of the subject, we invite you to read or reread the characteristics specific to this species, previously detailed in this Mag.
Playa Del Carmen - Mexico
No other place of observation has the exceptional peculiarities of this seaside resort located south of Cancun, Mexico, namely a hot and shallow water with good visibility. It has recently been proven that a large amount of Bulldog sharks migrate into the shallow waters of Playa del Carmen from November to March, when the water temperature drops below 27 ° C. They are nevertheless more easily observable in scuba diving from December to February.
For some super-predators, the presence of food is a determining factor in the choice of its habitat. Thus, the presence of the Bulldog shark in Playa Del Carmen coincides with that of the crowned amberjacks (Seriola dumerili). When yellowtails migrate, many bulldogs still remain in the area, which does not lead us to really associate the presence of these sharks to a track exclusively food.
Another very interesting hypothesis: all sharks are female and half of them are full! It would seem, therefore, that the Playa Del Carmen spot constitutes a resting area for the females because they find food in abundance there, before continuing their annual migration north to give birth. Current research will validate or invalidate these theories….
The dive area is called " Deep jardines »
Access to the site, recently recognized as a marine protected area following the Cop 13 held in Cancun last December, is regulated by the relevant local authorities in partnership with a NGO Saving Our Sharks. Thus, the slots for observation dives are open from 8h in the morning to 11h and 13h to 15h.
The spot is located about 300 m parallel to the beach. From the edge, access to the site takes less than 5 minutes! There is a gently sloping sandy bottom with a depth of between -22 m and -28 m and regularly exposed to the current. Two types of dives are possible:
- The chance encounter with a dozen individuals evolving on their territory with a proximity of observation which will depend on the goodwill and the interest of sharks for groups of divers.
- The second possible dive is a dive where the sharks are fed, the feeding.
The operators practicing this dive have ropes on the bottom with a buoy on the surface to facilitate access to the area and a correct release for the launchings. The bottom is - 24 m in this area. Access to the feeding dives is from 11 a.m. to 13 p.m. and from 15 p.m. to 16:30 p.m.
In both cases, the dive is done kneeling or lying on the sand for an average duration of about thirty minutes. The cost is about $ 95 for observation dives and up to $ 200 for bait diving, or feeding.
Ponta Do Ouro - Mozambique
Getting there is not easy. The access points of this small seaside resort in southern Mozambique are, in fact, restricted. You have to either land in South Africa in Durban and go up to the Kosy Bay border at 5 h north road, either land in Maputo then take the tracks south to 160 km and 7 h later, in Ponta Do Ouro.
It's on the dive site of Pinnacle, 11 km from the beach of Ponta we find the gathering of sharks bulldogs. According to scientific studies, the community is estimated at about 40 sexually mature male and female individuals. From one year to the next, some tagged individuals return to the site and new ones arrive. They reach Pinnacle and its surroundings, during November until the peak of concentration and activity, mid-January. Then, little by little, they disappear until the end of March.
Sharks find on this site in full exit of the channel of Mozambique an exceptional hunting area, located in the middle of a marine reserve. The food being abundant, an extraordinary pelagic activity converges there. Crossing other species of sharks in the water is quite likely, if not certain.
If bulldogs are concentrated in numbers on Pinnacle, it is most likely due to the fact that this site represents an exceptional hunting area, especially for the full females who find in this habitat a place where to eat easily, before committing a long migratory journey to the Zambezi river to give birth.
When the weather is good, get on site, at 4 miles parallel to the coast takes 20 min, in rough weather about 45 min. As this lift is continuously exposed to the current, the launching areas, north and south, vary greatly. It is advisable to be a good diver in good physical condition.
The dive plan is classic: immerse yourself, reach the sector in the - 40 m zone, stay there until the first stages appear, which is enough time to interest a few sharks, then leave the zone and drift in open water. It is strictly forbidden to feed sharks in the reserve but the site is constantly frequented by sport fishermen and spearfishers, the activity of divers in the water column, with the help of some fireworks, bottles of water. he bursting water and flashers used by underwater hunters soon brought up to fifteen bulldog sharks around the group. They will follow the group until it comes out of the water, an hour later on average.
During this dive it is not uncommon to cross scallop hammerhead sharks (Sphryna lewini), sharks with white tips of reef (Carcharhinus albimarginatus) And some sharks lined (Carcharhinus limbatus). Occasionally too, with a bit of luck, a tiger shark (cuvier galeopig) or one whale shark (Rhycodon typus) can be observed.
This dive, at a cost of about 45 $, is best done in the morning when the activity of the sharks is the most intense.
Diving with bulldog sharks
Rather benthic, the bulldog shark swims above the bottom in search of an odor, a sound or a signal sent by a possible prey. It's time for tracking. Once his prey is spotted, he seldom makes approach turns and quickly goes on the attack. He leaps on his prey at a brisk pace from below, rarely leaving him a chance to escape. It is an innate reaction to an interpretation biologically rooted in its genes. It is therefore clear that when a diver observes a bulldog shark moving in the water column, exposing its potential predators to its sensitive area, its belly, the shark is in full confidence and completely controls its habitat and its inhabitants. Any vertical approach from bottom to top is hunting or intimidating behavior.
As long as the sharks remain cautious, whether they are on the bottom around the divers at a distance, without passages in the middle or above the dive, without frontal approaches, the risk factor remains low. Over time, sharks gain confidence and allow for incursions closer and closer to the divers, on shorter frequencies. It is therefore necessary to limit the immersion time with these animals. Even if the danger is low, you should never forget that you are immersed in the company of one or more large predators and that their character can be unpredictable. Spasm, a sign of territoriality, a sign of nervousness or a sudden onset of speed should be considered as signs of active intimidation and must end the immersion.
In addition to the briefing, psychological preparation of the divers is essential before these special meetings:
- Refer to the strict instructions dictated during the briefing;
- Wear a dark full suit with gloves, slippers and balaclava.
Not have material of a clear or shiny color, or which protrudes;
- Limit its sound impact when entering the water and during the entire dive;
- Immerse yourself quickly and stay in a group;
- Always keep your eye on the closest sharks. Often look behind
self. Pay particular attention to large individuals;
- Keep a safety distance of at least 5 m between sharks and divers;
- Never pass below a group of sharks, stay at their level or
slightly above;
- Maintain an upright or kneeling position on the substrate to appear neutral and
more imposing;
- Stay constantly grouped because an isolated diver is more vulnerable;
- Never back up in the face of a frontal approach; use an overflow to repel an overly curious shark firmly but gently.
- If you use artificial lights, be careful! Some sharks can be
stimulated by recharging batteries or being frightened by flashes;
- If a diver of the group is not comfortable, the group leaves the area
calmly keeping the sharks in sight.
Technical Sheet
- The Bulldog Shark has a massive build, a stocky, packed and short body with a rounded, wide, extremely short muzzle and very small eyes.
- Its color can range from gray, light or dark, to olive brown. The belly is whitish. A light gray spot covers the top of the head of sexually mature specimens.
- It is a so-called benthic shark, that is to say that it evolves mainly above rocky or coral substrates close to the coast, at depths less than 60m. It swims mostly above the bottom and very rarely ventures into open water. The Bulldog Shark is also called the Zambezi Shark. It has the particularity of applying osmoregulation which allows it to acclimatize perfectly to hypo-saline waters. It uses this advantage to give birth to the juveniles, sometimes hundreds of kilometers inland up rivers and streams. Its favorite biotopes, that is to say its living environments, are shallow areas, regularly stirred by waves where part of its food chain is found in turbid waters, such as coral reefs. not far from the beaches, the outlets of estuaries, even the mouths where there is a strong industrial activity. They are also present near the coast where human seaside activity, swimming and surfing, for example, is important. He therefore shares his daily life in areas frequented by humans, which means that he is often involved in attacks, which is directly linked to his bad reputation.
- It is often confused with the bull shark (Tachar carcharias) because the English vernacular name of the bulldog shark is Bull sharkwhich literally translates as " bull shark And so is confusing. In order not to be mistaken with other species of the family of Carcharhinidaebecause there is no distinctive point on its fins, the eye is located vertically from the end of its lower jaw. It can measure up to 4 m, but most individuals do not exceed 2,80 to 3 m.
- The Bulldogs sharks are social predators that evolve into hierarchical groups. They are extremely territorial. We find them in different gatherings, such as migrations related to reproduction, births and places rich in food where they settle down part of the year.
It is the shark responsible for 80% of the bites and deadly attacks on humans each year.
Text, video and drawing: Steven Surina