Thus far, for Burkinabe and Sub-Sahelian fish species, little knowledge exists about fish assemblages regarding their composition, their habitat preferences, or their sensitivity to or tolerance of human pressures. The knowledge of essential fish habitat for spawning, breeding, feeding, or growth to maturity is an important management tool for a healthy ecosystem and sustainable fisheries. Therefore, they are potential indicators of environmental changes and trends in general aquatic biodiversity, since they interact with other aquatic organisms via predation, nutrient input, and mechanical effects. Because fish cannot easily migrate between aquatic systems, they have to adapt to changing conditions or die. Native fish species are well adapted to their environment to an extent that some species use the entire river continuum from the headwaters to the estuaries within their life cycle. The loss of habitat and human pressures led to a decline in fish populations in terms of total population, biodiversity, and average fish size. Moreover, large reservoirs have severe downstream effects such as altered flow and sediment regime, a change of water parameters (temperature, oxygen, suspended solids, etc.), erosion, missing flood pulses, decreased fish recruitment, and disturbed river biota.

Many reservoirs are not passable for fish due to lacking or poorly built fish passages. , more than 50% of the annual discharge of the Nakanbé basin is held in these reservoirs by dams. The construction of reservoirs increased fishery landings by 15 times since 1950, employing more than 30,000 fishermen and several thousand women for processing and selling the fish. About 85% of all built reservoirs are smaller than one million cubic meters (Mm 3), whereas the two largest ones contribute to more than 60% of the national capacity. These are mainly used for agriculture, livestock farming, and fisheries.

As a reaction to severe droughts in Burkina Faso, more than 1400 reservoirs of 1 to 25,000 ha surface area were built since 1950. The Volta Basin has lost almost 97% of its original forest cover, which is a good indicator for watershed degeneration. Similar pressures are also reported in Burkina’s water bodies, e.g., over abstraction, reservoir degradation, and pollution with agricultural chemicals. Frequent pressures on African water bodies include (1) water shortage and water abstraction, (2) pollution (suspended solids, solid wastes, organic and agricultural chemicals), (3) damming, (4) deforestation, and (5) overfishing. The natural habitat conditions are altered by human activities. The outcomes of this study provide basic knowledge of habitat availability, habitat use by fish, species associations, and human pressures and therefore provide the basis for effective conservation and management of fish populations.

Relative abundance either dropped ( Mormyridae) or increased ( Cichlidae, Cyprinidae) with rising pressure intensity, and some sentinel taxa ( Auchenoglanis, Hydrocynus) were only found in low-pressure sites.

Results show that physical parameters influence fish community composition and abundances and, when indexed according to pressure type, are linked to responses in fish metrics. Habitat preferences of four key species ( Labeo coubie, Bagrus bajad, Chelaethiops bibie, and Lates niloticus) were linked to ecological habitat conditions. Fish communities cluster into four distinct types, each dominated by either Cichlidae, Clariidae, Cyprinidae, or Alestidae and accompanied by specific other families and genera of fish. Fish communities, available abiotic habitat conditions, habitat use, and human pressures were assessed and analyzed. Surveys in four different regions sampled 18,000 specimens from 69 species during the dry season. This research provides the first data-driven basis for sustainably managing fish and associated aquatic and terrestrial habitats. Little knowledge exists about fish assemblages regarding their composition, their habitat preferences, or their sensitivity to or tolerance of human pressures. Human pressures and loss of natural fish habitats led to a decline in fish populations in terms of abundances, biodiversity, and average size in sub-Sahelian Burkina Faso.

Upper volta religion