With 75 million square kilometres, the Indian Ocean is the third largest ocean, if you don’t count the polar sea. Its biodiversity is higher than that of the Atlantic and the Caribbean, but lower than that of the Pacific. On the border to the Pacific, the Southeast Asian islands, we find the highest ocean biodiversity on earth! In the winter months of the northern hemisphere, summer prevails south of the equator. Then the sea plankton develops, and the largest fish of the seas, the long whale sharks growing up to 12 m, cross the strait between Madagascar and the African mainland. Actually we wanted to approach the whale sharks from the coast of Mozambique, but the journey to Tofo in Mozambique would have been too time-consuming. So we decided on Nosy Be on the northwest coast of Madagascar, which also has its own airport. From Germany we continued via Mauritius and Reunion to Nosy Be.
The next morning we took two motorboats out to the open sea. Strictly speaking, however, not really to the open sea, but into an area between the island Nosy Be and the mainland Madagascar, where the water was quite calm. The smoother the sea surface, the better you will find the whale sharks. We were looking for bird gatherings above the sea surface. As soon as plankton accumulates somewhere in larger quantities, small fish approach in large shoals. These in turn attract seabirds and large predators such as tunas and mackerels. I suspect that the whale sharks notice this turmoil and then aim for the spot. They also eat their fill and the poor sardines all end up in these robbers’ stomachs. Mantas also take part in the plankton hunt.
The first plankton eater to appear was not a whale shark, but a manta ray, the largest ray species in our oceans.
We steer the boats as cautiously and closely as possible to the action and let ourselves slide into the water. And then we see the gentle giants. The first sight is somehow unreal. You have seen hundreds of whale shark photos - but the live view is overwhelming. Completely noiselessly they swim towards me, turn slightly so as not to collide and disappear into the deep blue of the sea.
Ready to snorkel, we sit next to the outboard engine at the boat's stern. As soon as the boat stops, we go carefully and quickly into the water towards the whale shark.
Only very rarely does a whale shark stay near a human. But when it happens, usually with playful, young animals, it is a fascinating sight. At the surface of the water, the snorkelers are busy moving, and the whale shark keeps coming back to them and making contact. Both sides seem to be having fun! When he has had enough, he simply turns away. Even at his slowest speed no one can follow him.
On the second day we stay with the whale sharks for another two hours before heading out to the really open sea to look for humpback whales. After two hours of searching in moderate waves we find whales. But they aren’t lying quietly at the water surface, they’re moving north. Our skipper tries to drive in front of them to set us down in their swimming direction. But in the deep blue of the ocean we cannot see them, even though we are only a few meters away from them.
In the afternoon we return to Nosy Be. Some of us are still seasick, others are fit and ready to explore the reefs from the beach. And it is worth it! The coral reefs are full of live, intact corals.
Straight from the beach into water which is almost 30 °C. After a few meters we find our first coral formations. But we could do without the plankton constantly stinging us in the water!