Before the swimmer’s eyes, glowing flecks shine like stars eerily transposed into the depths of the sea. Through a dark-blue veil of water, a huge shape gradually resolves itself, rising slowly and majestically towards the surface.
After hundreds of sightings, Brad Norman’s blood still thrills as the great, spotted whale shark comes fully into view, gliding effortlessly forward, its pale, metre-wide mouth agape to scoop up thousands of litres of protein-rich sea water. "When they are down deep, they look like a star field under water. As you swim above, the shark’s body seems to disappear and its white spots light up like stars in the night sky. It’s an awe-inspiring sight."
The imagery illumines the abiding passion of this 38-year-old Australian naturalist who has dedicated most of his adult life to the pursuit, identification, understanding and protection of the world’s largest fish, Rhincodon typus, the aptly named whale shark. Reaching 18 metres in length, the huge beast resembles nothing so much as "a bus under water", Norman says. Yet an animate, placid, occasionally inquisitive bus, pursuing its mysterious life across tens of thousands of kilometres of open ocean.
A Species Under Threat
The whale shark was first recorded in 1828, and only 350 sightings were registered in the ensuing 150 years. Recent growth in underwater tourism has brought a surge in sightings. Yet the whale shark remains elusive, and the International Union for Conservation of Nature (IUCN), which engaged Norman to assess the species, regards it as "vulnerable" to extinction. It is protected in only a handful of countries.
The whale shark is one of only three sharks that are filter-feeders, using gill rakers to scoop up krill (shrimp), small fish and other tiny ocean life as its sole source of sustenance. It has never been known to attack humans. Tagged individuals have been tracked for 13,000 kilometres across the Pacific, and 3,000 kilometres in the Indian Ocean. It has an uncanny instinct for locating food concentrations. It is sighted at more than 100 places around the globe — including the Philippines, the South China Sea and Indonesia, off India, Australia and Africa, off Mexico, the United States and the Galapagos Islands (Ecuador). Yet it remains so scarce almost nothing is known of its abundance, breeding or habitat preferences. It has few natural enemies, though orcas and predatory sharks may attack young whale sharks. Now, however, the whale shark has joined the long list of species to suffer the ravenous human appetite for seafood. Its flesh, fins and body parts are appearing in growing quantities in Asian markets.
Brad Norman is determined to find out far more about these fish. His visionary plan to involve thousands of ordinary people worldwide in the photo-monitoring and conservation of whale sharks, significantly enhancing knowledge of this elusive species, earned him a Rolex Award for Enterprise.
Since his first awed encounter in 1995, in Western Australia’s Ningaloo Marine Park, Norman has strived to uncover all he can about this lordly animal, whose ancestry extends back 400 million years. "My first encounter seemed quite surreal. There was this huge, living thing coming directly towards me. My eyes were popping out of my head. I almost swallowed my snorkel. I was screaming silently to myself in excitement," he recalls. "Yet, oddly, I wasn’t afraid. I just floated there, too amazed to swim after him.”
As his encounters multiplied, Norman grew to appreciate many features of the whale shark. Its economical 1-to-1.5 metres per second cruising speed was perfect for observation. Though able to dive as deep as 1,500 metres, it often cruised conveniently near the surface. Its placid temperament made it safe compared with other big sharks. Yet it could also be dynamic: "I once observed seven in an area where there was a huge swarm of krill, a real soup of food in the water. They were charging through it, mouths open, thrashing around. That was a big adrenalin rush. I never felt frightened, but I did keep my arms down and made myself small.”
"Even with something as big as a whale shark, you’re not afraid – and nor is it. It is a calming experience. You feel at one." Swimming alongside its head, Norman has seen its little eye turn, observing him – perhaps a glimmer of acknowledgement. "Maybe it just thinks I’m a big remora [sucker fish]," he laughs. Nonetheless, he respects the shark’s brute power, and has assisted in the drafting of guidelines for divers and tour operators worldwide explaining how to behave around whale sharks.
A Breakthrough in Identification
Norman’s love of the ocean was born on the golden beaches of Perth, on Australia’s Indian Ocean coastline, where he body-surfed as a youngster. This led to diving and, via a science degree, to a deep interest in marine conservation which he has pursued as a researcher and fisheries management consultant.
His encounter with the Ningaloo whale sharks was a life-altering experience. The shark was an unknown, and there was little money for its study or conservation. Norman survived hand-to-mouth on sporadic grants, and funded much research himself. Burning the midnight oil, he mounted national and international campaigns for the whale shark’s conservation, emerging as a global authority on the animal and its needs. He helped authorities develop plans for its protection and wrote scientific reports and information for visitors.
Many mysteries are yet to be resolved. While young male sharks gather at Ningaloo, no one knows where the females collect or where the sharks breed. The key to studying their thin, dispersed and cryptic demographics lay in identifying individuals. Norman’s painstaking research proved each has a pattern of white spots on its body as distinctive as a human fingerprint. This gave him the idea of using underwater camera images as a practical, non-invasive way to identify individuals. In 1999 Norman set up the ECOCEAN Whale Shark Photo-identification Library on the Internet, a global project to record sightings and images.
Despite the growing body of information, Norman had no efficient way to compare shots of whale sharks taken from different angles, under varying conditions and fish postures. In 2002, American computer engineer and fellow diver Jason Holmberg contacted him. After discussion, Holmberg agreed to help organize and automate the ECOCEAN database. He explained the photo-ID problem to a friend, NASA-affiliated astronomer Zaven Arzoumanian, whose colleague Gijs Nelemans brought to their attention a technique used by Hubble Space Telescope scientists for mapping star patterns, known as the Groth algorithm, which the team then adapted to map the patterns of white spots on the shark’s hide. It took many months of intense mathematical calculations and computer programming to refine the algorithm for use on a living creature —but in the end they gained a breakthrough for biology, a reliable way to identify individuals in virtually any spotted animal population. In December 2005, the three described their findings in the Journal of Applied Ecology. More than 500 whale sharks have been identified and added to the database using the technique.
For survival, whale sharks depend on huge bursts of tiny sea life which reflect the condition of the oceans and their bio-productivity. Since whale sharks travel immense distances to collect food, the demographics of these fish can be an indicator of ocean health — and of the human impact on it.
Divers worldwide can now follow Norman’s simple guidelines for photographing whale sharks and log their images, activities and locations on the ECOCEAN site, where they are automatically catalogued, matched and, if possible, identified as belonging to a known individual. Each new image will help Norman compile a map of where whale sharks live and their migratory patterns. And contributors receive notification of all past and further sightings of the sharks they photograph. Together, the images are helping to build a global picture of the abundance, health and fluctuations of the whale shark population. "Just about anyone with a disposable underwater camera can now play a part in helping to conserve whale sharks, and so monitoring the health of the oceans," Norman explains. "It gives people a direct stake in its stewardship."
Ecotourism as a Key to Conservation
With the Rolex Award money, Brad Norman is devoting two years full-time to his project, training local authorities, tourism operators and 20 research assistants around the Pacific, Atlantic and Indian oceans to observe, record and protect whale sharks. In this way he will develop whale shark photography as a significant tool for conservation.
He will also explain to those who hunt the shark that there is more to be gained by leaving it alive. Ningaloo’s whale sharks draw more than 5,000 visitors a year, mainly from April to June, generating ecotourism worth an estimated US$10 million. A live whale shark earns far more than a dead one. "The whale shark is worth saving — and we can do something about it," says Norman. "It is a big, beautiful and charismatic animal, and not dangerous. It is a perfect flagship for the health of the oceans."
Published in 2006