KEY POINTS:
On one of those glorious, sun-filled days that Western Australia is famous for, I found myself immersed in the ultramarine splendour of the Indian Ocean.
Ningaloo Reef, the largest coastal fringing reef in the world, was living up to its reputation. Kaleidoscopic coral bommies of every conceivable shape were bathed in sunlight and myriad tropical fish darted among the multi-coloured nudibranchs and sponges. Dazzling weed gardens waved to and fro in a sparkling fantasia of colour and life.
Our group of high-spirited snorkellers was barely a kilometre off the beach, where white silica sand merges with the vivid red of ancient cliffs. As we moved into deeper water there was no sensation of cold or danger. The ocean held us in its warm embrace.
The kindred feeling of travellers sharing an adventure was exhilarating, but tempered with the knowledge that ominous dark shadows could emerge from the depths at any time.
This part of the Coral Coast, 1200km north of Perth, Western Australia, is known for its giant manta rays and prowling tiger sharks, along with more amenable aquatic mammals such as dolphins and dugongs.
Suddenly, out of the dark veil of the deep ocean, a huge grey shape emerged with a chilling shark-like profile. My first heart-stopping sight was of a gaping, one metre wide frog-like mouth. The mouth was moving towards me on a collision course. I was momentarily stunned and unable to move. My silent scream was lost in the depths. I thought, I was about to be swallowed whole. At the last momentI was galvanised into action and finned hard to get out of its way. A long, drooping pectoral fin brushed against my chest as the gentle giant slid past.
A dark, knowing eye with a pale blue and yellow pupil, was locked on to me as it passed. In that instant I tried to sense whether that eye was expressing mere curiosity or perhaps a sense of wonder and trust as two intelligent species interacted at a primal level. I fancied there was a vestige of mutual understanding in the brief contact and still believe this to be so.
Its vast flank reminded me of a granite mountain slope, rising to a curved prominence, the dorsal fin, which had the appearance of a submarine conning tower. Then the huge vertical tail fluke came level with me and it flexed ever so gently to maintain steady forward motion.
What was most remarkable about this giant whale shark was the checkerboard pattern of white star-bursts spread over its flank. They were as bright as the Milky Way on a clear night and seemed to glisten and shimmer under the slanting shafts of sunlight.
Back on board the boat our group is more than high-spirited, we are ecstatic. Ballistic even, as we exchange high fives and cavort about, bouncing off the cabin walls with the excitement of it all. We have had a whale of a time.
We have been swimming with a whale shark, the largest fish in the ocean. It was a surreal and breathless encounter with an incredible hulk. He was definitely a shark, but given his close resemblance to the cetacean species, the whale part of his name has clearly been added to do justice to his immense size. Our new acquaintance was 6 metres long, but his cousins can measure up to 18 metres and can weigh 21 tonnes. Ningaloo Reef is recognised as having the most predictable seasonal aggregation of whale sharks in the world and is the best place to see them in the wild.
The driving force behind this annual 1000km migration from tropical waters around Christmas Island, Indonesia and Timor is, of course those old faithful primeval instincts of food and sex. In this particular case, sex comes first. Not a jaw-dropping, mind-boggling coupling of two mighty star-crossed lovers, but rather a very public and non-intimate display by the 250 different species of coral polyps that have built this magnificent reef.
Every year as the full moon rises in March and April, the minute coral polyps on Ningaloo Reef simultaneously release a vast cloud of bright pink eggs and bundles of sperm. This ethereal pink soup floats above the reef, causing all manner of aquatic predators to salivate. The smallest creatures who seek out this seminal bounty are the krill, plankton and small pelagic fish, which go berserk at the prospect of an orgasmic feast.
The largest creatures are the whale sharks that are classic baleen feeders that cruise majestically through the potent mixture, sucking in every tiny organism in their path.
The whole pink farrago is strained through the fine mesh of their gill rakers by the tonne - the greatest gourmet banquet on earth.
Remarkably, local scientists are able to identify every individual whale shark by their checkerboard star pattern.
Photos of the star patterns are analysed using Nasa software. This was developed to map star clusters in the sky as part of the Hubble space craft guidance and navigation system. The whale shark clusters are like personal fingerprints as every pattern is unique. Marine scientists are thus on first name terms with these forbidding but lovable creatures.
A vision of this gentle giant of the reef looming out of the void will always remain with me. It's a unique privilege and a stellar experience to swim with this heavenly creature - a timely reminder that our lonely planet still has the capacity to surprise and humble us.
*Paul Rush travelled as a guest of Tourism Western Australia and Qantas.
- Detours, HoS
