Experiencing the challenge of the Great White Shark

Research and Ecotourism on one of the most charismatic creatures in the oceans


A BRIEF BIOLOGICAL OVERVIEW


The Great White Shark, within the monotypic genus Carcharodon, is related to four other Mackerel sharks (Mako, Isurus spp. and Porbeagle or Salmon shark, Lamna spp.) in the Family Lamnidae. Arguably equalled only by the Killer Whale (Orcinus orca) as an apex marine predator, the White Shark occupies a cosmopolitan range throughout temperate seas and oceans, occasionally penetrating tropical zones. He is mainly an epipelagic dweller of neritic waters, being found from the surfline to well offshore, at the surface and to depths over 900 meters on the bottom. They commonly patrol small coastal archipelagos inhabited by pinnipeds, rocky headlands where deep water lies close to shore and offshore fish reefs, banks and shoals.
White Sharks colour varies from almost black to slaty-grey or dun above, with the ventral surfaces predominantly white. The maximum size attained by White Sharks remains a matter embroiled by debate and spurious information. Adult females can reputedly attain 7 metres based on an unconfirmed specimen from Kangaroo Island, Australia, taken in 1987. A further female taken off Filfla, Malta, in the same year was reported as 713 centimetres Total Length (TL). It is however, realistic to suggest that maximum length of this species actually lies in the range of 550 to 600 centimetres Total Length. Claimed solitary creatures, recent studies have suggested a complicate social structure and hierarchy based on size and power. New findings draw ideas on their complex way of life and behaviour, poor understood for the expert, and completely unknown for the rest of the human beings.


EXTREME RESEARCH: IN THE QUEST ON THE ENIGMATIC PREDATOR


Although all of us regularly have experienced the feeling of thirst, huger, or anger, we rarely experience the fear of being eaten by a predator. This primordial feeling “travelling” within our genes since the wake of humankind, builds in our “claimed” well-developed mind a sentiment of panic, respect and in some people, desire of killing. Precisely, this hate for the would-be “monster” of the oceans during the past decades has lead to its uncontrolled slaughter and almost extinction in some areas. However, the future for the “beast” looks quite promising; that fear the Great White exerts on people has intrinsically increased the willing of knowing beyond his “killing label”. Serious scientific research apart from media coverage have disclosed information and facts about the mysterious life of these elusive predators, telling the scientific community and the general public that we know almost nothing about the life of this colossus of the oceans.

The Great White probably did inhabit many parts of the globe, but in the last century, it has been cornered to a bunch of places, where the quest for this animal can start. Research aims to explain what they do, and why they do it, taking into consideration ecobiological, ecophysiological, and behavioural aspects, as well as how the oceanographic parameters affect they movements. Searching for the causes of accidents and attacks on people conform an important part of the research as well. The final goal of all the studies is directed towards its conservation; in other words, the underlying reason of much of the scientific research at the moment is orientated towards the knowledge of their populations, migration routes, predatory behaviour, behavioural ecology, and other aspects of their life. Extensive research might reveal important details that will be of paramount importance for the complete protection and conservation of the species.

South African waters are nowadays one of the most important focuses of research on the Great White, and have achieved indeed the reputation claimed. Seal Island, near Cape Town, where we can watch the classical aerial predatory events and Dyer Island with its rocky counterpart, Geyser Rock, are the best two places on Earth to watch this fearsome predator in its natural habitat. Scientific research has taken various ways, and different projects have been developed to investigate different aspects of their life. My own experience has been devoted to Photo ID projects, where dorsal fin photographs are taken, acting as a fingerprint, which allows the establishment of population numbers and dynamics, as well as migration patterns. The posterior section of the dorsal fin, breaks, bends, and twists, presenting a series of characteristic notches that allow individual shark identification throughout their whole life. Databases are used to store all the photographs, observations, and other material, and scientific work can be done on it. I have also worked on telemetry studies; in other words for the novel reader, following animals without seeing them. Telemetry comprises an area of the broad spectrum of the remote sensing, which gear is designed to be able to gather data on animals without the need to bear visual contact or manipulate them. They are captured once, and tagging devices are attached to them, so they can be detected, and after that, data on their behaviour and environmental conditions can be stored and transmitted manually or via satellites to the scientific computers.



Preliminary results on their behavioural ecology in Mosselbaai (Eastern Cape) and Dyer Island reveal a great degree of phylopatry, that is, they tend to come back to their preferred sites after migration or movements across the coastal environment. In the case of Mosselbaai, they tend to hang around the beach from the Seal Island to the mouth of a river. There is no conclusive reason to explain why they stay there, but it seems a tranquil environment, with some scattered food on the bottom, as well as oxygenated waters. They could favour physiological constraints for respiration by staying near the surf zone, where more oxygen dissolves into the water solution, and then they could swim slower, saving energy. Indeed, their slow metabolism allows long periods of time without eating, but when they do it, they will gorge up themselves. They normally feed on Cape Fur Seals (Arctocephalus pusillus pusillus) and whale carcasses (sporadically) when being adults, but will predominantly prey on fish at juvenile growing stages. Hunting for seals it is not an easy task, and Great Whites must improve their skills if they are to be able to feed on the pinnipeds. These speedy animals have learnt all the tricks and manoeuvres to escape from their predator, and then, Great Whites need to use the element of camouflage and surprise at its maximum if they want to catch a meal. Failures are scarce (increased in young sharks), but some stranded seals at the island show the toll paid for being unwary or being surprised (normally by juveniles) as fresh or healed wounds on their backs. Some sharks do hunt during the light hours, but the majority will have a go during the night, when the seals cannot detect them visually. They hunt just after sunset for a couple of hours, and then at dawn until the sunrise. Both predator and prey must refine their aquatic skills if they want to survive, but one needs to feed and the other needs to escape; who will win the challenge will be a matter of experience and strategy in the waters of South Africa.


ECOTOURISM FRENZY: WORKING TOWARDS A PUBLIC CONSERVATIONIST APPROACH

Marine ecotourism is a component of the wider ecotourism industry that is considered to be growing rapidly both in terms of its volume and its value. This growth is particularly acute insofar as such activities typically occur in places that could be considered peripheral in spatial, temporal, and/or economic terms. By peripheral I do mean, areas found on the periphery of what is considered human establishments; distant relatively untouched places, were the tourist could experience the natural environment in a pristine manner. Indeed, in many cases the very peripheral nature of these destinations has to some extent protected target species, habitats, landscapes, and seascapes from the negative consequences of unsustainable “economic development” in the past. Ecotourism is therefore associated with geographically remote places and spaces; people watching whales in Antarctica, or diving with Great Whites in South Africa. I personally believe that there is a sentiment of wildness in ourselves, a feeling of “returning” to the past, experiencing our earliest origins in contact with the natural world, observing it as “it used to be”. That sensation is the one normally sought by many people travelling such large journeys to those remote locations. This spirit found within the public, is the one we need to foster if we want to protect and conserve the natural resources as well as the living creatures around us.



In the case of the Great White, taking people to watch them, swimming with them in the cages, and observe them around the boat can change their perception of this fearsome predator. The vast majority of the tourists that have been close enough to a White Shark acknowledge that they are quite, mysterious, impassive, very curious animals. They wonder themselves if the animal they see in front of them is the same they saw in Spielberg’s film devouring people, and being labelled as a man-eater. Experiences like this one are the ones we need the general public to get involved with, if we want to preserve these terrific animals for the coming decades.

South African waters meet the requirements for the ecotourism industry to be a fructiferous place, and thus, the conservation initiative is at the top of their agenda. If sharks vanish, ecotourism industry suffers. What is the outcome? Industry takes the lead and does its best to conserve the animals, which are directly their economical incentive. This kind of approach is the one needed nowadays, and it is becoming a matter of fact. My own experience reveals days of more than 20 encounters, which seems incredible bearing in mind the elusive nature of this shark. The potential for research and ecotourism industry is thus immense. However, I would remind for those interested, that the peak months for watching the Great White are during the austral winter (August, September, October, and even November). Murky waters might be in place, and swells at sea will be common, but the abundance of sharks will be incredible and great adventures will be feasible. I do recommend to take underwater camera, but the footage could be quite disappointing, especially at the beginning. The best is to take digital cameras with housing, so loads of pictures can be taken, and then analyze for the worthwhile ones. What should be “a must” for everyone is to take a normal camera to capture on image the movements of the shark around the boat, leaps, or the awesome approaches to the cage. By all means, we should try to enjoy the trip, learning as much as possible on these incredible creatures.

Just to conclude I would like to stress that if we want to protect ourselves, we need to protect the oceans and the creatures in them. Protection and conservation are concepts that go together, but are seldom understood by everybody in society; we should work together within an informative and communicative framework if we want to achieve those goals. By that, I mean, that the education of the general public towards a conservationist approach should start in ourselves, as individuals. As soon as those simple concepts are learnt by the majority of us, we will be able to create a more reasonable and sustainable world.




PHOTOGRAPHIC COMMENTS AND DETAILS

The photographic equipment used during the research study consisted on a NIKON D70 with two camera bodies: a polarized 28-80 mm and a polarized 70-300 mm zoom. I felt quite happy with both; in the relatively close shots, I could get extraordinary pictures. I used polarized zooms because during the majority of the field days, sun conditions were continuous. Operating with a special camera device, I could avoid the shiny and reflectance bits that some shots disclosed. With the second zoom (70-300 mm), I was able to get distant views, which I mainly used in trying to capture the numerous whales at that time of the year (Southern Right Whales (Eubalaena australis), and Humpback whales (Megaptera novaeangliae)). Other equipment used was a Konica Minolta DiMAGE Xg, which I remember using in a couple of “wet situations” attached as a critter cam to a pole, in order to get close views and sex recognition by absence or presence of claspers (reproductive organs). For the wounded seal pictures, I borrowed a friend’s camera (Panasonic DMC-FZ20).


Mr. Mario Lebrato
Department of Marine Biology and Oceanography
National Oceanography Centre
University of Southampton
United Kingdom
http://www.noc.soton.ac.uk/
ml1104@soton.ac.uk


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