I’d only ever seen whale sharks at the surface before. Swimming with whale sharks in Indonesia was something unexpectedly rewarding. This article is one of a few I’ll be writing about the experience, and about the region’s whale sharks in general. It adds to an understanding of the incredible power and significance of wildlife in eastern Indonesia. To be among this was a genuine privilege.
Remember to sign up for updates. There are two more articles to follow. One on the relationship between whale sharks, people and ecosystemsHow ecosystems function An ecosystem is a community of lifeforms that interact in such an optimal way that how ecosystems function best, is when all components (including humans and other animals) can persist and live alongside each other for the longest time possible. Ecosystems are fuelled by the energy created by plants (primary producers) that convert the Sun's heat energy More. The other on the way that the Saleh Bay ecosystem operates and the significance of whale sharks.
Land of volcanos
It was half an hour before sunrise. Beams of orange sunlight were starting to glow in the humid air, stencilled onto the deep blue of the morning twilight sky. Wisps of cloud hugged the summit of Mount Tambora. This region is one of the most volcanically active places in the world. Tambora’s last eruption in 1815 was the largest in recorded human history.
Before dawn
This morning the air was thin, cool and silent. The wind had dropped overnight and the tranquility of dawn suppressed the volume of our excitement. We were all sitting in a circle on board a zodiac preparing our masks, snorkels, hoods, cameras and nerves. We were about to enter pitch-black water knowing that within twenty metres, swum several of the largest animals on Earth.
Plankton rising
Our first glimpse of a whale shark through the mirth was an animal hanging almost vertically in the water column. Saleh Bay is about 100m deep here and packed full of planktonA soup of micro-organisms. Usually refers to all the zooplankton and algae in the ocean but can also be used to describe tiny insects in the atmosphere (see aerial plankton). More. We could see brilliant blue dots glistening in the water. These were sapphire copepods. The crystalline structures in their paper-thin bodies reflects blue light even under the gloomiest of conditions. These plankton, along with the whale sharks, migrate to the surface at night and this is when the local people fish. People and whale sharks share this home and have become accustomed to both living and fishing together.
The bagans
Local fishers had completed hauling their net from below the bagan about an hour before we arrived. The vessel is made from wood and bamboo. The central part is for accommodation and storing fish. Two outriggers are slung from a mast with steel cables and powerful lights are used to concentrate fish, krill and squid around the net at night. For thousands of years the Sama-Bajau people have fished this region and whale sharks are sacred to them. Although bagan fishing is a recent phenomenon, it’s always been customary for them to protect the sharks. So they give back a portion of their catch. The sharks have grown accustomed to this relationship.
First light
As the sun rose above the volcanic peaks, the first shafts of golden light revealed the sharks’ full length. There were altogether five animals. Saleh Bay is mostly home to male sharks and the largest we estimated at about 8m which would make it a mature male. But scientists have established that in 90% of cases we tend to underestimate the length of whale sharks … so this individual could easily have been even bigger. In the presence of such large and powerful animals, precise size doesn’t really matter.
Plankton and remoras
The water was green and peppered full of life flowing past in a moderate current that meant we snorkelers had to keep swimming upstream like weird neoprene fish. We saw chains of salps, a gelatinous filter-feeding organism with prominent brown nucleus. There were also lots of small umbrellaed jellyfish and microscopic swimming plankton everywhere. Aboard the largest of the whale sharks there was one lonely remora (suckerfish), a smaller one on the tail of another.
A cultural practice
At the expense of other less mature whale sharks the largest shark fed almost continuously for the four hours we were there. Unsurprisingly vertical feeding uses less energy than pushing a 20 tonne body through the water for hours. The crew on the bagan were dishing out krill from buckets, literally tipping it into hungry mouths. It was like watching baby birds begging for food in the nest. As westerners we worry about the ethics of this type of practice. But who are we to question the relationship between two animals who’ve shared an ecosystem for thousands of years? This is a topic I cover in another of my articles about the Sama-Bajau people.
Floating people
For our part, swimming with whale sharks in Indonesia, meant simply floating at the surface. We either held on to a rope or gently frog-kicked to avoid being swept away in the gentle current. There wasn’t much point in swimming after the animals as they were curious enough to come to us from time to time. The hardest thing for swimmers, on occasion, was to back up!
Vertical feeding
As krill scraps were added to the surface, the shark would emerge with its snout just above the surface, then sink with its mouth open. The subsequent rush of water into the cavernous mouth would be followed by a flourishing of the gills. Up to 600 cubic metres of water an hour can be consumed by a shark and this has to be filtered by the gill-rakes before the food scraps are swallowed. The rows of tiny black dots below the eye are ampullae of Lorenzini – electro-receptors. For much of the time whale sharks feed in the deep, dark ocean. These no doubt help them detect patches of food more effectively than their tiny eyes.
Graceful behemoths
Whale sharks would circle back around the boat, often curious enough to swim straight at us and only turning away at the last moment. Their movements, as you’d expect, are sinuous and graceful.
Kings Cross Station
Although some sharks were small by comparison, snorkel masks offer quite a restricted view. From time to time, it felt like Kings Cross Station at rush hour. You’d be admiring one shark and suddenly your view would be ambushed by one, two or three others arriving from different directions. Although capable of bursts of speed, they generally moved slowly, allowing both sharks and swimmers to respect each other’s space. When your view was occasionally interrupted by a shark less than a metre below, you’d have time to manoeuvre. Then they would often deliberately curl the top of their tail fins to avoid contact. The whole experience was quite serene.
In the moment
By mid-morning we were exhausted and it was time to leave the whale sharks to their daily routines. As the sun rose higher and the plankton swam deeper into the abyss the whale sharks would follow. For most of their existence is lived in secrecy. We know little about them and for that we can be thankful. The people of this region have always protected them and that alone affords us the privilege of not only being among whale sharks but being a small part of their lives too. Swimming with Whale Sharks in Indonesia is more than just ecotourism. It’s a glimpse into our past and our own existence and how much we share with Earth’s extraordinary creatures. Sometimes it’s nice to simply reflect on this and try not to think too hard about it.
Read the whole trip report
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