Oil extraction imperils Africa's Great Lakes

Environmental DNA barcoding reveals general biodiversity patterns in the large tropical rift Lake Albert

Lake Albert, Africa's seventh-largest lake and a biodiversity hotspot, faces significant environmental challenges, including unregulated anthropogenic pressure and a lack of comprehensive biological studies. To address the scarcity of biodiversity data, we utilized environmental DNA (eDNA) metabarcoding to assess the lake's eukaryotic and metazoan communities. Surface water samples were collected at three distinct locations: close to the southern inflow of the Semliki River, the central part of the lake, and close to the northern inflow of the Victoria Nile and outflow of the Albert Nile. We aimed to study ecological patterns across the lake, focusing on sequence variant richness and community composition, testing for differences among locations and between shoreline and pelagic zones. Consistent with previous morphology-based observations, our results revealed differences in community composition among the three sites, with cyclopoid copepods dominating the communities. Distance from shore was a significant factor influencing community composition, confirming expectations about the effects of nutrient and oxygen availability gradients. However, the lack of comprehensive reference sequence data limited accurate taxonomic assignments. Despite these limitations, our study demonstrates that eDNA metabarcoding is highly useful for assessing biodiversity in underexplored tropical freshwater ecosystems. We advocate for urgent efforts to generate reference sequences from tropical regions to enhance the utility of eDNA for biodiversity monitoring and conservation. Our findings underscore the potential of eDNA in providing insights into ecological patterns of entire communities and emphasize the need for comprehensive studies addressing the full taxonomic spectrum in tropical freshwater ecosystems.

Monitoring biodiversity loss in rapidly changing Afrotropical ecosystems: an emerging imperative for governance and research

Africa is experiencing extensive biodiversity loss due to rapid changes in the environment, where natural resources constitute the main instrument for socioeconomic development and a mainstay source of livelihoods for an increasing population. Lack of data and information deficiency on biodiversity, but also budget constraints and insufficient financial and technical capacity, impede sound policy design and effective implementation of conservation and management measures. The problem is further exacerbated by the lack of harmonized indicators and databases to assess conservation needs and monitor biodiversity losses. We review challenges with biodiversity data (availability, quality, usability and database access) as a key limiting factor that impacts funding and governance. We also evaluate the drivers of both ecosystems change and biodiversity loss as a central piece of knowledge to develop and implement effective policies. While the continent focuses more on the latter, we argue that the two are complementary in shaping restoration and management solutions. We thus underscore the importance of establishing monitoring programmes focusing on biodiversity-ecosystem linkages in order to inform evidence-based decisions in ecosystem conservation and restoration in Africa. This article is part of the theme issue 'Detecting and attributing the causes of biodiversity change: needs, gaps and solutions'.

The taxonomic diversity of the cichlid fish fauna of ancient Lake Tanganyika, East Africa

Ancient Lake Tanganyika in East Africa houses the world's ecologically and morphologically most diverse assemblage of cichlid fishes, and the third most species-rich after lakes Malawi and Victoria. Despite long-lasting scientific interest in the cichlid species flocks of the East African Great Lakes, for example in the context of adaptive radiation and explosive diversification, their taxonomy and systematics are only partially explored; and many cichlid species still await their formal description. Here, we provide a current inventory of the cichlid fish fauna of Lake Tanganyika, providing a complete list of all valid 208 Tanganyikan cichlid species, and discuss the taxonomic status of more than 50 undescribed taxa on the basis of the available literature as well as our own observations and collections around the lake. This leads us to conclude that there are at least 241 cichlid species present in Lake Tanganyika, all but two are endemic to the basin. We finally summarize some of the major taxonomic challenges regarding Lake Tanganyika's cichlid fauna. The taxonomic inventory of the cichlid fauna of Lake Tanganyika presented here will facilitate future research on the taxonomy and systematics and the ecology and evolution of the species flock, as well as its conservation.