The morning wind is now calm. The sun burns the sandy banks of Senga Bay and warms the clear water of the great lake. There is blue as far as the eye can see; only one single rocky island a couple kilometers away, Namalenje, breaks the horizon. At the beginning of the afternoon in the shade of some acacias, we wait for our boat, arranged the day before with local fishermen, impatient to get our fins wet around that little island. Time passes and with surprise and a bit of worry, we finally get on a large pirogue dugout of a baobab branch. Our two strong rowers synchronise their effort and after half an hour we reach the granitic reefs of the island.

Equipped with our fins, masks and snorkels, the lake so still, the water so clear…we dive in.

       Within the first metres, we witness an explosion of life. One is literally surrounded by fish. A myriad of cichlids dart around us seeming indifferent to our presence. The eye is at first attracted by the most colourful subjects, mainly dominant males guarding their territory, chasing away the unwanted, and parading themselves among the females. But it is not the majority of the specimens who graze, forage, hunt, swim a couple metres from us, whose colour pattern is less visible; they are the females, the juveniles or the subordinate males. Even with a trained eye, identifying a species is not an easy task. Thanks to a playful trick of evolution, there are more than 1000 species of cichlids in Lake Malawi. The island of Namalenje offers just a glimpse of the extreme biodiversity that one can observe in its surrounding waters.

On the big blocks of rock which form the base of the island, one most commonly sees Mbunas (group of endemic herbivore cichlids), some cyprinids (Labeo cylindricus, Barbus spp.) and depending on the luck of the crevice, a large eel (Anguilla bengalensis labiata). Just under the surface, in the zone tossed by waves and drenched with light, Labeotropheus trawavasae graze on seaweed by pushing their characteristic prominent noses against the rocks. A couple metres deeper, each fish has their own special way to take full advantage of the plant cover that grows on the rocks, which is also called aufwuchs (“abundant growth”). Maylandia, Tropheops, Cynotilapia, Melanochromis, Pseudotropheus, … all share the same zone and take care not to swim into neighbouring territory, as to avoid a quick and painful reprimanding. Hierarchy is more or less respected and the large Petrotilapia reigns. Magnificent Protomelas taeniolatus Namalenje complete the picture.

A bit further out to sea in the water column, Copadichromis borlevi, jacksoni, and chrysonotus catch drifting plankton. There are predators like Tyrannochromis, Dimidiochromis and other Lichnochromis on the look-out; woe to the young Mbuna who gets in their way.

At the foot of the island, between ten and fifteen metres deep, a great sandy plain stretches out to sea. There lies the territory of Lethrinops and Fossorochromis. As the aquatic tour continues, a seagrass bed of Vallisneria carpets the sandy sea floor a couple metres from the base of the island. A school of Placidochromis johnstoni swims away on our arrival, and young Nimbochromis livingstoni hide in the seagrass. A slender Mylochromis sphaerodon watches the scene, posted just over this sub-lakeside prairie. It is time to go back, the end of the afternoon is near and the wind is picking up. On our way back, at a drop-off, over the sand, we witnessed such a sight: majestic Dimidiochromis kiwigue parading at the top of their nest. Swimming proudly above those great cones of sand (the diametre at the top of a nest is about 1 metre), males were challenging each other, with their fins fully displayed and their bright colours shining in the sunlight. Our Malawian friends had to ask us several times to get out of the water. We finally get onboard, and go back to the mainland. The sun shines red light over the bay, night falls on her majesty Nyassa.

(Paco)