Molecular investigation of harmful cyanobacteria reveals hidden risks and niche partitioning in Kenyan Lakes DOI Creative Commons
Brittany N. Zepernick, Lauren Hart, Emily E. Chase

et al.

Harmful Algae, Journal Year: 2024, Volume and Issue: 140, P. 102757 - 102757

Published: Nov. 10, 2024

Despite the global expansion of cyanobacterial harmful algal blooms (cHABs), research is biased to temperate systems within north, such as Laurentian Great Lakes. This lack diversity represents a significant gap in field and jeopardizes health those who reside along at-risk watersheds south. The African Lake, Lake Victoria, understudied despite serving second largest lake by surface area demonstrating year-round cHABs. Here, we address this knowledge performing molecular survey cHAB communities three anthropogenically ecologically important freshwater Victoria's Kenyan watershed: Winam Gulf (Lake Victoria), Simbi Naivasha. We identified bloom non-toxic Dolichospermum toxic Microcystis Gulf, with data suggesting sulfur limitation shapes competition dynamics between these two bloom-formers. Though did not detect Naivasha, it contained genera amongst lakes. In turn, our results indicated methane metabolism may allow picoplankton outcompete genera, while Synechococcus spp. serves source sink system. exhibited Limnospira at time sampling very low abundances present. Subsequently, were employed design screening risk assessment framework for local stakeholders. Cumulatively, work increase efforts on international scale an impetus monitoring scale.

Language: Английский

Bacterial community and cyanotoxin gene distribution of the Winam Gulf, Lake Victoria, Kenya DOI Creative Commons
Katelyn M. Brown, Katelyn B. Barker, Ryan S. Wagner

et al.

Environmental Microbiology Reports, Journal Year: 2024, Volume and Issue: 16(3)

Published: June 1, 2024

Abstract The Winam Gulf (Kenya) is frequently impaired by cyanobacterial harmful algal blooms (cHABs) due to inadequate wastewater treatment and excess agricultural nutrient input. While phytoplankton in Lake Victoria have been characterized using morphological criteria, our aim identify potential toxin‐producing cyanobacteria molecular approaches. was sampled over two successive summer seasons, 16S 18S ribosomal RNA gene sequencing performed. Additionally, key genes involved production of cyanotoxins were examined quantitative PCR. Bacterial communities spatially variable, forming distinct clusters line with regions the Gulf. Taxa associated diazotrophy dominant near Homa Bay. On eastern side, samples exhibited elevated cyrA abundances, indicating genetic capability cylindrospermopsin synthesis. Indeed, Nyando River mouth 2022, exceeded 10 million copies L −1 where there more than 6000 Cylindrospermopsis spp. cells mL . In contrast, southwestern region had mcyE (microcystin synthesis) detections Bay Microcystis Dolichospermum observed. These findings show that within a relatively small embayment, composition toxin synthesis cHABs can vary dramatically. This underscores need for multifaceted management approaches frequent cyanotoxin monitoring reduce human health impacts.

Language: Английский

Citations

6
Metagenomics reveals spatial variation in cyanobacterial composition, function, and biosynthetic potential in the Winam Gulf, Lake Victoria, Kenya DOI Creative Commons
Lauren Hart, Brittany N. Zepernick,

Kaela E. Natwora

et al.

Applied and Environmental Microbiology, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 8, 2025

ABSTRACT 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 gulf’s cyanoHABs, thus, strategies employed for survival proliferation by toxigenic cyanobacteria this remain largely unexplored. Here, we used metagenomics analyze Gulf’s composition, function, biosynthetic potential. Dolichospermum was dominant bloom-forming cyanobacterium, co-occurring with Microcystis at most sites. Planktothrix were more abundant shallow turbid Metagenome-assembled genomes (MAGs) harbored nitrogen fixation genes, suggesting diazotrophy as a potential mechanism supporting nitrogen-limited gulf. Over 300 gene clusters (BGCs) putatively encoding synthesis toxins other secondary metabolites identified across gulf, even sites where no visible cyanoHAB events. Almost all BGCs had known product, indicating diverse novel repertoire capable synthesizing or potentially therapeutic metabolites. MAGs contained mcy genes hepatotoxic microcystins are concern drinking water safety. These findings illustrate spatial variation their available dominate different ecological niches. This study underscores need further use genomic techniques elucidate dynamics mitigate effects cyanoHABs associated environmental, economic

Language: Английский

Citations

0
Introduction to the special section: Aquatic resources for a sustainable future and blue economy prosperity for the African Great Lakes region DOI Creative Commons
R. Michael L. McKay, Julius O. Manyala, Fiona Nunan

et al.

Journal of Great Lakes Research, Journal Year: 2024, Volume and Issue: 50(5), P. 102413 - 102413

Published: Aug. 5, 2024

Climate change, overfishing, pollution, and habitat degradation are no longer distant threats demand our collective action. Rising to this challenge, the Aquatic Resources Blue Economy Conference (ARBEC) held in Kisumu, Kenya served as a call action for sustainable aquatic practices protection of blue economy resources. The holds much promise yet global community faces unprecedented environmental challenges, it's potential hinges on ability make informed, science-driven decisions.

Language: Английский

Citations

2
Metagenomic sequencing of cyanobacterial-dominated Lake Victoria—an African Great Lake DOI Open Access
Brittany N. Zepernick, Lauren Hart,

Kaela E. Natwora

et al.

Microbiology Resource Announcements, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 12, 2024

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

Language: Английский

Citations

2
Spatio-temporal Trends of Mercury and Stable Isotopes in Lower Food Web of Winam Gulf, Lake Victoria DOI
Dennis Otieno, Ken G. Drouillard, Linda M. Campbell

et al.

Bulletin of Environmental Contamination and Toxicology, Journal Year: 2024, Volume and Issue: 113(3)

Published: Aug. 23, 2024

Language: Английский

Citations

0
Assessing the Potential Impacts of Contaminants on the Water Quality of Lake Victoria: Two Case Studies in Uganda DOI Open Access

Brian Nalumenya,

Matteo Rubinato, Jade Catterson

et al.

Sustainability, Journal Year: 2024, Volume and Issue: 16(20), P. 9128 - 9128

Published: Oct. 21, 2024

Nutrients are essential for the growth of aquatic life; however, in excess, they can result a decline water quality, posing serious risks to both human and organisms. Human activities, such as urbanisation, industry, farming, increase amount nutrients other elements that reach receiving waterbodies like Lake Victoria Uganda, which be problematic at elevated levels. There is therefore strong need evaluate recent changes pollutant concentrations their potential negative effects. To contribute this gap explore Victoria, series chemistry data (phosphate, nitrate, potassium, ammonium, sodium, sulphate, silica chlorine) was collected between 2016 2023 Uganda’s Napoleon Gulf (NG) Murchison Bay (MB), primarily by Ministry Water Environment (MWE). These locations were chosen based on vicinity expanding urban centres agriculture, also areas where fishing frequently occurs. The datasets different depths (0.5–24 m). Data analysed with use IBM’s Statistical Package Social Sciences (SPSS 28.0) software confirmed excessive pollutants within MB compared NG. analysis identified nutrient types exceeded internationally recognised thresholds relating acceptable quality during collection period. Seasonal variations observed, dry season; levels, NG showed higher wet season. study’s capacity inform local authorities policymakers about major sources pollution crucial importance beginning address impacts health life.

Language: Английский

Citations

0
Molecular investigation of harmful cyanobacteria reveals hidden risks and niche partitioning in Kenyan Lakes DOI Creative Commons
Brittany N. Zepernick, Lauren Hart, Emily E. Chase

et al.

Harmful Algae, Journal Year: 2024, Volume and Issue: 140, P. 102757 - 102757

Published: Nov. 10, 2024

Despite the global expansion of cyanobacterial harmful algal blooms (cHABs), research is biased to temperate systems within north, such as Laurentian Great Lakes. This lack diversity represents a significant gap in field and jeopardizes health those who reside along at-risk watersheds south. The African Lake, Lake Victoria, understudied despite serving second largest lake by surface area demonstrating year-round cHABs. Here, we address this knowledge performing molecular survey cHAB communities three anthropogenically ecologically important freshwater Victoria's Kenyan watershed: Winam Gulf (Lake Victoria), Simbi Naivasha. We identified bloom non-toxic Dolichospermum toxic Microcystis Gulf, with data suggesting sulfur limitation shapes competition dynamics between these two bloom-formers. Though did not detect Naivasha, it contained genera amongst lakes. In turn, our results indicated methane metabolism may allow picoplankton outcompete genera, while Synechococcus spp. serves source sink system. exhibited Limnospira at time sampling very low abundances present. Subsequently, were employed design screening risk assessment framework for local stakeholders. Cumulatively, work increase efforts on international scale an impetus monitoring scale.

Language: Английский

Citations

0