A scientific mission to survey the ecology of fish communities in lake Tanganyika (Tanzania)
About 670 km long, Lake Tanganyka is one of the largest lakes in the world. It is also a veritable laboratory of evolution inhabited by hundreds of fish species that are found nowhere else (endemic). Among them, more than 220 belong to the single Cichlidae family.
For scientists, Lake Tanganyika offers countless examples of the speciation process wich leads to the appearance of new species. The specific ecological condition of this lake with the dimensions of an inland sea gave birth to many diverse morphological types, strikingly reminding a wide variety of different marine fish families. Studying how tens of closely related species share the same habitat resources is interesting in terms of speciation (level of ecological differenciation according to kinship), and in comparison with their marine counterparts ("ecological equivalents"). ...
This scientific diving mission lasted from April 11 to 27, 2015. It was held in Kipili (south of the lake, Tanzania) with a team of 8 volunteer divers. Its main goal was to assess habitat preferences of the different species sharing the same rocky environment in a given location. After an exploration phase around several islands, we selected a survey site in Mvuna Island (see map). The survey protocol we used had already been tested during several field missions. The principle is to "quantify" as many features as possible of the close environment of a given number of fish individuals by semi-quantitatively assessing a series of variables describing the habitat (topography, living cover...) and the way the fish places itself within this context. The results have not been completely analysed yet. However, a few graphs are provided here together with the photos.
This trip was organised in partnership with the French tour operator Blue World, and was hosted by Lake Shore Lodge in Kipili, a renowned high standard resort. The team managed by Patrick Louisy (Emmanuel Gouin, Marie Gromand, Patrick Noël, Marie-Joëlle and Pierre Rouillan, Denis Sabatier, Hervé Thédy) deserves congratulations for their hard work and enthusiasm. And many thanks to Louise and Chris Horsfall and all the Lake Shore Lodge team for their kindness and involvement in the achievement of our mission.
pictures
