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| The White Shark Research Institute | |
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Material provided by Keith Hadland, hadlandk@lgwct.logica.com Please contact him for further information. There is also a report from Keith's 1995 trip. |
The White Shark Research Institute is a privately funded organisation
with no government support of any form. Due to the White Shark's undeserved
negative public profile, it has not been possible to gain corporate support.
For these reasons, the WSRI has had to rely almost exclusively on the
general public for its support and existence. The bottom line is that
without the enthusiastic concern and support of its members, the WSRI
would have an almost impossible task in carrying out reseach as well as
fighting for the rights of sharks. BACKGROUND This opportunity was taken with both hands by the WSRI. The status of the White Shark is now being used to its full potential in trying to change public opinion of sharks to a positive and more realistic view. The goal is to make people realise that sharks are not mean monsters - they are simply wild animals doing their best to surivive in an increasingly pressurised environment. WSRI SUMMARY To date the WSRI has worked with hundreds of individual White Sharks and have tagged upwards of 140 of these animals. Of the animals tagged, a 43% resighting rate has been recorded, which suggests a relatively small population of White Sharks. This is of great concern when cosidering that South Africa possibly maintains the largest population of White Sharks in the world. A serious problem in the size mix of these animals has been observed. Findings thus far indicate the near absence of sexually mature White Sharks and year old animals. The initial questions posed were : How many White Sharks are there? What is the sex and size mix? Where, when and how far are they moving? Where are their breeding grounds? How does the White Shark fit into the environment and how much impact does it have on the environment? What effests do human related activites and environmental degradation have on the species? These questions are slowly being answered. The answers to these and other questions are paramount if the survival of the White Shark is to be ensured. This animal, like all top predators, is extremely vulnerable to over-exploitation and unless we know exactly what the situation of the species is, it will be impossible to successfully manage and conserve this magnificent animal. It would be a sad and irreparable day for nature and a humiliating day for mankind if we were to lose the White Shark due to lack of knowledge and understanding. Over the past three years the WSRI have been inviting people from the media, both nationally and internationally, on research trips. This strategy has proved to be invaluable in developing positive and sound relationships with the media in different fields. Without exception, after experiencing the White Shark in its natural environment, a strong and positive attitude has developed. Journalists who would otherwise write any nonsense about the White Shark now contact the WSRI for accurate information before publishing. The WSRI are regularly approached by documentary companies wishing to film White Sharks. A policy of not becoming involved with traditional 'Jaws' like documentaries has been adopted by the WSRI. All documentary scripts are scrutinized by the WSRI and if it is found to promote the 'Jaws' image the WSRI will encourage the company to alter the script. If the company declines to do this, the WSRI will not become involved with that company. It is important for the general public to see White Sharks for what they are - superbly designed wild animals - and not man eating monsters blindly attacking boats and cages. The WSRI have recently completed a three month filming project with BBC Natural History and National Geographic. For the first time in history, the White Shark was filmed in its natural environment absent of human influences. This documentary (screened on BBC1 on Good Friday) will vastly change public opinion of the species. It is rightly predicted that this documentary will overshadow all previous documentaries and place the animal in a very positive light. INTRODUCTION OF THE WHITE SHARK COMMON NAMES: White shark, white pointer, great white and blue pointer. FIELD MARKS: Heavy spindle shaped body, moderately long, bluntly conical snout, small dark eyes, large flat, triangular, serrated, blade like teeth, long gill slits, large first dorsal fin, very small second dorsal and anal fins, strong keels on caudal preduncle, cresent shaped tail fin, body grey to blackish above, white below, dark spot at pectoral axle. SIZE: Size at birth is between 1-1.5m total length. Size at maturity is 3.5-4.5m for males and 4.5-5.0m for females. There is at present no evidence that males attain a larger size than the females. Available data suggests a max size of 6.5m for males and 7.5m for females. The weight of White Sharks of a given length can vary greatly between individuals, but a healthy animal of 7.0m would probably weigh in the region of 3000 to 4000kg. AGE and GROWTH: Preliminary investigations on the age attained by the White Shark, taken from annular rings in the vertebrae suggest that, provided one ring is added each year, males mature at about 9 years and females 13 to 15 years. Growth is estimated to be 25-30cm per year for the first 15 years and 22cm for older animals. A 7.0m animal could therefore be older than 30 years. It is possible that the White Shark may only add a ring every 2 years, so the above figures are speculative. REPRODUCTION: The White Shark has internal fertilisation. The male uses his claspers to fertilise the females. Courtship behaviour may occur, but little is known. The White Shark is live bearing and practices uterine cannibalism. White Shark litters are thought to be about 7 to 9 pups. The gestation period is not known but the large size of the pups suggests a gestation period of at least a year and possible as long as two. Fecundity of the White Shark is little known, but when considering the rarity of White Sharks less than 1.6m it would appear to be low. A female may only reproduce a few times in a lifetime. DISTRIBUTION & HABITAT: As presently known, the White Shark is primarily a coastal and offshore inhabitant of the continental and insular shelves of the temperate zones of the world's oceans. EXPEDITIONS The Expedition Sites: Struis Bay lies adjacent to the most Southerly point of the African continent, Cape Agulhas. As a White Shark area, Struis Bay is completely different to Dyer Island. There is no seal colony or island - in fact, seals are very rarely seen in Struis Bay. What attracts the White Sharks to this area is the abundance of fish and small sharks. The WSRI's working area is five nautical miles from the harbour and one mile from shore at a place called 'The Mouth'. This area is very wild and from the boat one can see 30km of unspoilt coastline. At Struis Bay, researchers once recorded 11 sharks around the boat. Depending on the sharks and the weather conditions the expedition will work at one or other of the above locations, or possibly at both. Work while on an expedition included tagging, behavioural studies, seal predation studies, filming and photographing and cage work. On certain expeditions there may also be some tracking work. From the shark cage it is possible to sex the animals, and to get the unique opportunity to study pigmentation, markings and behaviour from close range. The expeditions are shore based and researchers stay in comfortable houses on the mainland close to the research site. Each day, the expedition puts to sea in the 26' research vessel - this small vessel is used because of its low running costs, its speed and manoeverability (which makes it easier to work close to the animals) and because the smaller vessel provides the researchers with a much better perspective of the animal than if they were standing on the deck of a large boat. Research activity: The boat is then towed to the harbour and launched. On arrival at the chosen research site, the baits are set and chumming commences, then the crew settles down to wait for the sharks to appear. This can take anything from five minutes to several hours. Once the sharks arrive the day is taken up with tagging, observing, recording, photographing, filming and cage work. The return to harbour depends on the sharks and weather conditions, but is usually planned for about 16.00-17.00. Once back on dry land (with the boat recovered, refuelled and back at
the research base), the boat and all equipment is washed down and prepared
for the following day. Baits and chum are prepared and anything else needing
attention is taken care of before the next research day. When all of the
duties are taken care of, the crew can relax and ponder the day at sea.
On some evenings there are lectures, slide shows and films about the White
Shark. |
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