Diving with Whale Sharks in Western Australia

This article was contributed by Beccy Ingerson of Coral Coast Dive Centre, Western Australia. She can be contacted at ccd@telstra.com

Exmouth and the Ningaloo Reef, Western Australia, are famous for whale sharks. The whale shark is actually widely distributed throughout tropical regions of the world, but Western Australia has become a popular destination to interact with these giants of the ocean. People travel from all over the world for the opportunity to snorkel with the largest known fish, some of which reach up to about 12 metres in length. If anything, these animals are sharks' greatest ambassadors, negating the idea that all sharks have sharp, pointy teeth and are only interested in killing and eating humans. Few experiences can be more awesome than swimming with such a huge animal which feeds entirely on plankton.

Unfortunately whale sharks have more reason to fear humans than humans have to fear them. There is still a considerable trade in whale shark meat and the population has declined in recent years as a result of an increase in their commercial value. Taiwan and Thailand are two large markets for the meat and fins. Many countries of the Far East still place a high value on shark fin soup, a delicacy which can cost as much as $200 a bowl in Hong Kong. As a result, many sharks suffer from the barbaric practice of "finning". As the name suggests, the shark is caught, the dorsal fin removed and the shark then thrown back in the ocean to suffer a slow and painful death, usually by drowning.

A recent meeting of CITES, the UN Convention on International Trade in Endangered Species, voted to tighten the trade in both whale sharks, and another large shark species known in temperate waters, the basking shark, until scientists can find out whether they are endangered. The critical decision was reached in the final hours of the meeting and only after going to vote for a second time to reach the required two thirds majority.

The whale shark and basking shark have now been placed on CITES Appendix II. This listing will enable the international trade of these species to be monitored so that the effects of this trade can be more effectively gauged. It does not mean that either species is completely protected. The measure requires countries to take the necessary steps to prove that the trade in the sharks is not having a negative effect on their numbers. In spite of the size of the animals, little is known about the size of the populations of either species.

The proposal was rejected outright by pro-whaling countries Norway, Iceland, Singapore and Japan who feared that these restrictions would impact on commercially important fish species such as tuna. Other countries including the Philippines, India and the UK argued that there are tremendous benefits to keeping the sharks alive, and illustrated the cost benefits of eco-tourism as opposed to unsustainable harvests of shark fins.

The Philippines noted that whale shark populations had declined around the world in the period 1994-97: 70% in the Philippines itself, 48% in India and a staggering 99% in South Africa.

Whale shark sightings are extremely common on the Ningaloo Reef in the months of mid April-June. A spotter plane communicates with boats as it spots the large shadow of a whale shark near the surface. Interactions are regulated by CALM (Conservation and Land Management), which limits the number of snorkellers in the water with a shark to a maximum of 10, forbids the use of flash photography and lists guidelines including how long a single interaction with a whale shark may last.

Whale sharks are not the only sharks you can expect to see around Exmouth. Reef sharks, mainly white tip reef sharks, are regular sightings at many dive sites, particularly on the Navy Pier. Last summer there were over 20 whitetip sharks at the site, with up to 10 all reposing on the sand in one small area. Quiet approach and observation allows divers to get within metres of these sharks; often the first and closest underwater encounter with sharks for many of our divers. Other sharks we have recorded seeing include grey nurse, tawny nurse, grey shark, oceanic white tip, bronze whaler and cat sharks.

There is apparently a number of tiger sharks in the Ningaloo Reef area, but most divers never see one whilst diving. Described as unpredictable and a man-eater, the tiger shark does not enjoy the great media of their larger cousins, the whale shark. However, those divers who have had the rare opportunity to see one whilst diving, say that the shark shows no interest in humans. The more likely place to see a tiger shark is feasting on the dead carcass of a humpback whale and even then, they are very shy and will abandon the feast for quite some time upon the approach of a boat. There is a story of a security guard standing on top of the Navy Pier whilst divers were beneath the water at the famous site. He saw a large tiger shark playing in the bubbles of the divers, but when the divers surfaced, they hadn't seen the shark! The guard said it was the largest shark he had seen in 12 years of service.

Another unusual shark which is very commonly seen around our reefs is the wobbegong shark. The wobbegong is a nocturnal shark and spends most of the day sleeping on the bottom: although at the Pier, wobbegongs often favour a more elevated position amidst the pylons. They are very well camouflaged, with a motley colouring which blends in well with the background. Once spotted, they are easily identified by the beard like frills around their mouth. Divers can be lulled into a false sense of security by the inertia of the shark but beware: they have very fast reflexes and can deliver a nasty bite, usually provoked by some foolhardy action by the human!