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Funding biodiversity conservation strategies are usually minimal, thus prioritizing habitats at high risk should be conducted. We developed and tested a conservation priority index (CPI) that ranks habitats to aid in prioritizing them for conservation. We tested the index using 1897 fish species from 273 African inland lakes and 34 countries. In the index, lake surface area, rarity, and their International Union for Conservation of Nature (IUCN) Red List status were incorporated. We retrieved data from the Global Biodiversity Information Facility (GBIF) and IUCN data repositories. Lake Nyasa had the highest species richness (424), followed by Tanganyika (391), Nokoué (246), Victoria (216), and Ahémé (216). However, lakes Otjikoto and Giunas had the highest CPI of 137.2 and 52.1, respectively. Lakes were grouped into high priority (CPI > 0.5; n = 56) and low priority (CPI < 0.5; n = 217). The median surface area between priority classes was significantly different (W = 11,768, p <.05, effect size = 0.65). Prediction accuracy of Random Forest (RF) and eXtreme Gradient Boosting (XGBoost) for priority classes were 0.912 and 0.954, respectively. Both models exhibited lake surface area as the variable with the highest importance. CPI generally increased with a decrease in lake surface area. This was attributed to less ecological substitutability and higher exposure levels of anthropogenic stressors such as pollution to a species in smaller lakes. Also, the highest species richness per unit area was recorded for high‐priority lakes. Thus, smaller habitats or lakes may be prioritized for conservation although larger waterbodies or habitats should not be ignored. The index can be customized to local, regional, and international scales as well as marine and terrestrial habitats. [ABSTRACT FROM AUTHOR]

The processes driving primary productivity and its impacts on fish production were investigated in field trials in eight seasonal earthen wetland ponds ‘Fingerponds’ (192 m2) in Uganda between 2003 and 2005. The ponds were stocked by the seasonal flood with predominantly Oreochromis spp. at densities ranging from 0.1 to 0.5 fish m−2. Chicken manure (521, 833 or 1,563 kg ha−1) was applied fortnightly. Results showed that primary productivity was enhanced with maximum average net primary productivity (±Standard Error) of 11.7 (±2.5) g O2 m−2 day−1 at the Gaba site and 8.3 (±1.5) g O2 m−2 day−1 at the Walukuba site. Net fish yields were higher in manured ponds with up to 2,670 kg ha−1 yield for a 310 day growth period compared to less than 700 kg ha−1 in unmanured ponds. Fish production was limited mainly by high recruitment, falling water levels, light limitation from high suspended solids and turbidity, and low zooplankton biomass. It was concluded that Fingerponds have a high potential for sustainable fish production and can contribute to the alleviation of protein shortages amongst the riparian communities around Lake Victoria. Production can be enhanced further with improved stock management. [ABSTRACT FROM AUTHOR]

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The freshwater fisheries of Africa are important sources of income and protein for the people of the continent, and stocks of biodiversity for the world. This report discusses the experience for eight important lakes (Baringo, Chad, Kariba, Malawi, Naivasha, Nakuru, Tanganyika and Victoria), in order to provide an overview of the challenges facing the African freshwater systems, the interventions undertaken to manage the challenges, the inputs that have been required, and the lessons learned to guide further actions. In particular, the experience of the Global Environment Facility in promoting sustainable fisheries and lake basin management at five of these lakes (Baringo, Chad, Malawi, Tanganyika and Victoria) is discussed. The overall experience to date indicates a lack of effective management actions, as a result of limited accessibility and application of scientific information, poor dissemination of management information, inappropriate and un-harmonized fishery laws and regulations, inadequate enforcement of existing laws and regulations, weak institutions and institutional processes, and inadequate funds for implementing fishery programmes. [ABSTRACT FROM AUTHOR]

Lake Victoria is Africa's single most important source of inland fishery production. After it was initially fished down in the first half of the 20th century, Lake Victoria became home to a series of introduced food fishes, culminating in the eventual demographic dominance of the Nile perch, Lates niloticus. Simultaneously with the changes in fish stocks. Lake Victoria experienced dramatic changes in its ecology. The lake fishery during most of the 20th century was a multispecies fishery resting on a diverse lake ecosystem, in which native food fishes were targeted. The lake ended the century with a much more productive fishery, but one in which three specie--two of them introduced--made up the majority of the catch. Although many fish stocks in Lake Victoria had declined before the expansion of the Nile perch population, a dramatic increase in the population size of Nile perch in the 1980s roughly coincided with the drastic decline or disappearance of many indigenous species, Now, two decades after the rise of Nile perch in Lake Victoria, this species has shown signs of being overfished, and some of the native species that were in retreat--or even thought extinct--are now reemerging. Data on the resurgence of the indigenous species suggest that heavy fishing of Nile perch may enhance biodiversity; this has spawned renewed interest in management options that promote hath fishery sustainability and biodiversity conservation. INSET: Faunal collpase and resurgence in Lake Nabugabo. [ABSTRACT FROM AUTHOR]