Metagenomics reveals spatial variation in cyanobacterial composition, function, and biosynthetic potential in the Winam Gulf, Lake Victoria, Kenya.

The Winam Gulf in the Kenyan region of Lake Victoria experiences prolific, year-round cyanobacterial harmful algal blooms (cyanoHABs) which pose threats to human, livestock, and ecosystem health. To our knowledge, there is limited molecular research on the gulf's cyanoHABs, and thus, the strategies employed for survival and proliferation by toxigenic cyanobacteria in this region remain largely unexplored. Here, we used metagenomics to analyze the Winam Gulf's cyanobacterial composition, function, and biosynthetic potential.

Molecular investigation of harmful cyanobacteria reveals hidden risks and niche partitioning in Kenyan Lakes.

Despite the global expansion of cyanobacterial harmful algal blooms (cHABs), research is biased to temperate systems within the global north, such as the Laurentian Great Lakes. This lack of diversity represents a significant gap in the field and jeopardizes the health of those who reside along at-risk watersheds in the global south. The African Great Lake, Lake Victoria, is understudied despite serving as the second largest lake by surface area and demonstrating year-round cHABs.

Metagenomic sequencing of cyanobacterial-dominated Lake Victoria-an African Great Lake.

We report 40 metagenomic libraries collected from the Winam Gulf of Lake Victoria during May-July of 2022-2023 and an additional eight opportunistic libraries from adjacent Lakes Simbi, Naivasha, and regional river systems. The sampling period captured cyanobacterial bloom events - shedding insight onto community composition and genomic potential.

Exploring the morphological dynamics of Nile tilapia (Oreochromis niloticus Linn. 1758) in Victoria Nile as depicted from geometric morphometrics.

Background: Various anthropogenic activities continue to threaten the fish biodiversity of the East African water bodies such as the Victoria Nile. Although the Victoria Nile is a significant source of livelihood for human populations, the biology and ecology of Nile tilapia in this ecosystem remain understudied with little or no information on the morphology of the fish given varying and immense anthropogenic activities. Here, we use geometric morphometrics to examine the morphology/shape variations of Nile tilapia populations in Victoria Nile to gain insights into their current ecological state.

Cycles of fusion and fission enabled rapid parallel adaptive radiations in African cichlids.

Although some lineages of animals and plants have made impressive adaptive radiations when provided with ecological opportunity, the propensities to radiate vary profoundly among lineages for unknown reasons. In Africa's Lake Victoria region, one cichlid lineage radiated in every lake, with the largest radiation taking place in a lake less than 16,000 years old. We show that all of its ecological guilds evolved in situ.

The non-Haplochromis fish fauna in Uganda: an update on the distribution and a review of data gaps.

Freshwater fishes are the second most threatened group of vertebrates after amphibians. In most developing countries, the conservation of freshwater fishes is largely hampered by limited information and data. The Red List assessments by the International Union for Conservation of Nature (IUCN) provide a benchmark for monitoring and mitigating species extinction risk, but these assessments require, inter alia, quantitative information on the species range in the wild.

Characterization of Potential Threats from Cyanobacterial Toxins in Lake Victoria Embayments and during Water Treatment.

Africa’s water needs are often supported by eutrophic water bodies dominated by cyanobacteria posing health threats to riparian populations from cyanotoxins, and Lake Victoria is no exception. In two embayments of the lake (Murchison Bay and Napoleon Gulf), cyanobacterial surveys were conducted to characterize the dynamics of cyanotoxins in lake water and water treatment plants. Forty-six cyanobacterial taxa were recorded, and out of these, fourteen were considered potentially toxigenic (i.

High-resolution bathymetries and shorelines for the Great Lakes of the White Nile basin.

HRBS-GLWNB 2020 presents the first open-source and high-resolution bathymetry, shoreline, and water level data for Lakes Victoria, Albert, Edward, and George in East Africa. For each Lake, these data have three primary products collected for this project. The bathymetric datasets were created from approximately 18 million acoustic soundings.

Antimicrobial peptides from freshwater invertebrate species: potential for future applications.

Invertebrates are a significant source of antimicrobial peptides because they lack an adaptive immune system and must rely on their innate immunity to survive in a pathogen-infested environment. Various antimicrobial peptides that represent major components of invertebrate innate immunity have been described in a number of investigations over the last few decades. In freshwater invertebrates, antimicrobial peptides have been identified in arthropods, annelids, molluscs, crustaceans, and cnidarians.

Using sediment fingerprinting to identify erosion hotspots in a sub-catchment of Lake Kivu, Rwanda.

Sedimentation of water bodies affects water quality and biotic communities of aquatic ecosystems. Understanding the causes and origin of sediments is crucial for planning watershed management activities and safeguarding aquatic biodiversity and critical ecosystem services. Rwanda, as a hilly country, experiences increased sedimentation due to unsustainable land use practices in upstream catchment areas which negatively affects irrigation, fishing and hydropower generation.

Microplastic pollution in surface water of Lake Victoria.

Microplastic pollution of aquatic systems is a widely recognised environmental challenge. In this study, the occurrence, abundance, distribution and chemical nature of microplastics within the size range 0.3-4.

A review of the socioecological causes and consequences of cyanobacterial blooms in Lake Victoria.

Africa is experiencing high annual population growth in its major river basins. This growth has resulted in significant land use change and pollution pressures on the freshwater ecosystems. Among them, the Lake Victoria basin, with more than 42 million people, is a unique and vital resource that provides food and drinking water in East Africa.

Occurrence, distribution and size relationships of plastic debris along shores and sediment of northern Lake Victoria.

Plastic pollution has been reported in sediment, surface water and biota of freshwater systems especially in Europe, North and South America, and Asia with limited studies focussing on African great lakes. This study therefore investigated the occurrence, abundance and distribution of micro-, meso- and macro-plastic debris along shores and sediment of northern Lake Victoria. The abundance of micro-, meso- and macro-plastics measured as particles/kg dry sediment were in range of 0-1102, 0-218 and 0-100 respectively in shoreline sediment and 0-108, 0-33 and 0-77 respectively in lake sediment.

Predicted impacts of climate warming on aerobic performance and upper thermal tolerance of six tropical freshwater fishes spanning three continents.

Equatorial fishes, and the critically important fisheries based on them, are thought to be at-risk from climate warming because the fishes have evolved in a relatively aseasonal environment and possess narrow thermal tolerance windows that are close to upper thermal limits. We assessed survival, growth, aerobic performance and critical thermal maxima (CTmax) following acute and 21 d exposures to temperatures up to 4°C higher than current maxima for six species of freshwater fishes indigenous to tropical countries and of importance for human consumption. All six species showed 1.

Benthic macroinvertebrate community structure in Napoleon Gulf, Lake Victoria: effects of cage aquaculture in eutrophic lake.

An investigation was conducted on the macro-benthic fauna of the Napoleon Gulf in the northern part of Lake Victoria from March 2011 to December 2016 at the cage fish farm. The aim was to examine the likely impact of cage aquaculture on macro-benthic invertebrates. Cage aquaculture is now a common practice on Lake Victoria yet little is known about its long-term effect on macro-benthic faunal assemblages.

Historical deposition of persistent organic pollutants in Lake Victoria and two alpine equatorial lakes from East Africa: Insights into atmospheric deposition from sedimentation profiles.

Information on historical deposition of persistent organic pollutants (POPs) for African lakes is very limited. We investigated historical deposition trends and sources of POPs in sediment cores from Lakes Victoria (SC1), Bujuku (Buju2) and Mahoma (Maho2). The latter two lakes are situated in the Rwenzori mountain range in western Uganda.