I HAD A LONG-HELD DREAM, one common to many underwater photographers, and that was to take photos of a whale shark.
And now here I am close to realising that dream, because snorkelling with whale sharks is down as part of a dive-tour programme in the Philippines.
We’re woken at the crack of dawn and led to a bus. We will spend five hours travelling from Mactan in the northern part of Cebu island to the southernmost part of the island and a small town called Oslob. Most of the group are planning to have a sweet nap, but my thoughts about that long-awaited meeting with whale sharks won’t allow me to sleep.
There aren’t that many whale sharks left, and as they are spread over the vast oceans, we get the chance to see them only occasionally.
Until the beginning of the 19th century that privilege was limited to sailors voyaging in tropical and sub-tropical seas. This huge fish was said to be the Devil incarnate, thought to enjoy nothing better than overturning ships – and woe betide any seamen who should find himself into the water with them, because they would gobble up such prey a dozen at a time.
Those were the views of uneducated medieval fishermen, but even the more contemporary traveller Thor Heyerdahl devoted these gloomy lines to the shark: “The head belonged to a gigantic monster and it was so huge, so ugly that even the sea serpent, if it had appeared in front of us, wouldn’t have impressed us so much. Little eyes were sat on the edges of a wide and flat snout, the toad’s gorge with long fringe in the corners was no less than a metre and a half wide… Even Walt Disney’s vivid imagination couldn’t have created such a monster.”
The size of the whale shark’s gorge is impressive but modern scientists would raise strong objections to any suggestion of these huge fish ingesting an unfortunate swimmer. The whale shark might be colossal, but it has a pharynx only 10cm in diameter and an oesophagus that is joined to the stomach almost at right angles, which means that it cannot swallow long objects.
Besides, this shark is oriented to eat its natural food, krill, which is why it’s always ready to close its gorge when a big object is nearby. Divers can disturb and may even try to ride whale sharks, in which case the fish’s only (and quite sluggish) reaction is submersion to a depth beyond human capabilities.
This may interrupt the shark’s feeding, so thinking of this, many countries in which shark-tourism flourishes have created strict rules about “non-contact” communication with the whale sharks.
In Oslob, feeders scatter krill in certain parts of the sea during daylight hours, and whale sharks come to be fed there as if it’s some huge canteen. As they satiate themselves and leave, others take their places at the dining table.
I don’t know what the maximum influx of “guests” is, but I saw about seven sharks at the same time. Counting the number of spectators contemplating the eating giants was less easy, in fact impossible.
A fleet of boats from the local dive-centres and hotels were circling the feeders’ bangkas (local Philippine boats with outriggers), and dozens of scuba-divers, snorkellers and swimmers in life-jackets were landing from those boats.
Some were swimming cautiously at a distance, some striving to touch the sharks’ rough skin, others showing off for the photographer, lining up alongside the sharks – it looked like Disneyland in full swing, though instead of the hubbub of a noisy crowd, all I could hear was the rustle of the scuba gear and the gurgling of bubbles.
The heroes of the day were of course the whale sharks, carrying themselves calmly as if they were the only creatures in mid-ocean. Imperiously they ignored the confusion of humanity around them – their natural grandeur made us feel small.
Initially the sharks coming in to feed themselves seemed huge, but as our emotions slowly levelled out it was possible to estimate their sizes objectively. There were “little ones” of 3-4m in length, but I would put the biggest at about 8m, young teenagers in whale shark terms.
According to scientists, puberty comes when the sharks are about 8-9m long and 30-35 years old. The highest estimates of whale shark age and size abandon strict scientific concensus and enter the brightly coloured realm of fishermen’s stories.
THE MOST SCEPTICAL SCIENTISTS measure a whale shark’s natural lifetime to be around 70 years, while the more optimistic extend that to 100 years. Eyewitnesses have confidently stated that they have come across 150-year-old specimens. Scientists put the maximum size as 20m long and weight at about 34 tonnes, impressive enough, but the Internet is a kaleidoscope of tales of monsters weighing in at up to 40 tonnes!
The pattern of white transverse stripes and bright spots on the grey or grey-brown background of a whale shark’s back looks picturesque. Coastal dwellers have come up with many names for the whale shark based on this colouring, so in South America it’s called “domino”; in Madagascar “the one that has lots of stars”; on Java “a back of stars” and in South Africa “Father Shilling”.
Scientists have found out that this pattern is as individual as human fingerprints and doesn’t change as the fish grows up. This peculiarity is used to record sharks and to learn about their migration routes.
A whale shark comes to the feeder’s boat and waits for the next portion to fall into the water, at which point it slightly opens its wide jaws, and the water rushes in with a murmuring sound.
If a camera comes too close to a shark’s mouth, the owner will have to strain his or her arms to avoid the seething funnel engulfing it.
The whale shark needs from a couple of dozen to 100kg of food – plankton, small fish, squid or jellyfish – a day to fill itself, the amount depending on its size.
The density of plankton organisms in the oceans is not great (on average 4.5kg per cubic metre), so the whale shark has to filter huge amounts of water. Scientists confirm that this number can reach 6000cu m per hour.
The filtration process happens with the help of a fine sieve (the size of a cell can be of 1-3mm) made of gill arches, cartilaginous tissue and dermal teeth.
Whale sharks migrate seasonally to find more abundant hunting areas.
Once they have found fields full of plankton, the giants gather in big groups. In the Gulf of Mexico 420 specimens were detected in 2009 during a period of a mass fish-spawning (spawn is perfect food for whale sharks).
HERE IS ANOTHER SHARK coming up to the dining table. Having swallowed some food, it is disturbed by something (or someone), swerves dramatically and slips aside. Idlers who stay near its tail are literally “blown away”.
It’s true that a whale shark won’t attack a human deliberately, but no one is immune in a situation in which people can be hit by a mighty tail. Whale sharks wiggle their whole body while moving, and a tail-fin can move with great force.
Besides which, sometimes a whale shark may ram fishermen’s boats, not deliberately but because it isn’t exactly eagle-eyed. The crew find themselves in the water, and marine folklore gets one more horrifying story about a dangerous sea monster.
I watch the sharks for 30 minutes, and notice that they differ not only in their appearance but in behaviour. While some try to be unobtrusive and wait their turn for food, brasher sharks jump the queue, the queuers behaving as if that’s OK. It’s evident that this community has its own hierarchy.
Whale sharks’ behaviour may remain veiled, but their anatomy has been closely studied. They are known to be ovoviviparous, for example, developing eggs within the body, and those eggs become super-large – 60cm long and 40cm in diameter.
They are also extremely nutritious. In fact, the nutrient potential is so high that a baby shark leaving its egg doesn’t need to eat for several weeks, yet still grows by a centimetre every day.
Whale sharks have not been studied by scientists for that long. In 1828 a “baby fish” 4.6m long, stricken near the South African coast, was studied and described by an English naturalist called Andrew Smith, but the fact that aspects of their lives remain opaque is probably down to the comparative rarity of the species.
A trade in whale sharks exists in south and south-east Asia (according to some sources, fins from about 1000 sharks turn up each year on the Chinese market), but fishermen are reluctant to pass their catches onto scientists.
Only about 300 are known to have been examined in detail over what is almost two centuries.
But scientists are ringing the alarm bells, because they know there is little or no chance of encountering a 20m whale shark these days.
The maximum size of specimens being examined is no more than 12m, and their average size in populations threatened by humans (in the Taiwan region, for example) has dropped below the 5m mark. This is a “baby fish” that will be able to reproduce only in 15 years or so from now.
That’s why scientists are concerned that this unique species may vanish from the Earth before we have come to fully understand it.
Whale sharks are listed in the International Red Book, and many countries are broadening their efforts to protect them.
We can only hope that humans find enough wisdom to protect these good-tempered giants, and that the world’s oceans and seas won’t become too cramped to accommodate both whale sharks and people.