How healthy are the oceans? Ask a whale shark

Scientists are trying to learn about ocean health by monitoring whale sharks

- MATTHEW ABBOTT

On a calm morning in May, Brianna Beaulieu, a doctoral student in marine biology at the University of Western Australia, and several researchers from around the world boarded two research vessels bound for Ningaloo Reef on Australia's west coast.

The scientists have invested months of planning to spend just a few minutes in the water collecting data on one of the ocean's most mysterious animals.

Whale sharks are not whales. They are fish, the largest in the sea, and can grow up to 60 feet long. Yet, surprisingly little is known about their life cycle. Researchers still don't know where whale sharks mate, how often they breed or where they go to give birth.

Beaulieu and her colleagues hope to gain at least some insights into these giants. A whale shark can easily be spotted from the air, cruising just below the surface of the crystal-clear waters of the Indian Ocean. In May, whale sharks gather off the reef in numbers so high that, for the half-dozen spotter planes overhead, finding them is simple.

For the past 20 years, a team from the University of Western Australia has conducted annual fieldwork at Ningaloo Reef. Ningaloo is one of the world's longest fringing reefs, formed unusually close to shore, and is listed as a UNESCO World Heritage site.

The reef's shallow, turquoise waters are home to an extraordinary range of marine life. The whale sharks that migrate there each year offer a rare window for scientific study.