Lacustrine Cyanobacteria, Algal Blooms and Cyanotoxins in East Africa: Implications for Human and Ecological Health Protection
Timothy Omara,
Christine Betty Nagawa,
Christine Kyarimpa,
Stefan Böhmdorfer,
Thomas Rosenau,
Solomon Omwoma Lugasi,
Henry Matovu,
Silver Odongo,
Patrick Ssebugere
Affiliations
Timothy Omara
Food Safety Laboratories, Chemistry Division, Testing Department, Standards Directorate, Uganda National Bureau of Standards, Bweyogerere Industrial and Business Park, Kampala P.O. Box 6329, Uganda
Christine Betty Nagawa
Department of Forestry, Biodiversity and Tourism, College of Agricultural and Environmental Sciences, Makerere University, Kampala P.O. Box 7062, Uganda
Christine Kyarimpa
Department of Chemistry, Faculty of Science, Kyambogo University, Kampala P.O. Box 1, Uganda
Stefan Böhmdorfer
Institute of Chemistry of Renewable Resources, Department of Chemistry, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz-Straße 24, 3430 Tulln, Austria
Thomas Rosenau
Institute of Chemistry of Renewable Resources, Department of Chemistry, University of Natural Resources and Life Sciences Vienna (BOKU), Konrad-Lorenz-Straße 24, 3430 Tulln, Austria
Solomon Omwoma Lugasi
Department of Physical Sciences, Jaramogi Oginga Odinga University of Science and Technology, Bondo P.O. Box 210-40601, Kenya
Henry Matovu
Department of Chemistry, Gulu University, Gulu P.O. Box 166, Uganda
Silver Odongo
Department of Chemistry, College of Natural Sciences, Makerere University, Kampala P.O. Box 7062, Uganda
Patrick Ssebugere
Department of Chemistry, College of Natural Sciences, Makerere University, Kampala P.O. Box 7062, Uganda
Advected cyanobacteria, algal blooms and cyanotoxins have been increasingly detected in freshwater ecosystems. This review gives an insight into the present state of knowledge on the taxonomy, dynamics, toxic effects, human and ecological health implications of cyanobacteria, algal blooms and cyanotoxins in the East African Community lakes. The major toxigenic microalgae in East African lakes include Microcystis, Arthrospira, Dolichospermum, Planktolyngbya and Anabaenopsis species. Anatoxin-a, homoanatoxin-a, microcystins (MCs), cylindrospermopsin and nodularin have been quantified in water from below method detection limits to 81 µg L−1, with peak concentrations characteristically reported for the wet season. In whole fish, gut, liver and muscles, MCs have been found at concentrations of 2.4 to 1479.24 μg kg−1, which can pose human health risks to a daily consumer. While there have been no reported cases of cyanotoxin-related poisoning in humans, MCs and anatoxin-a (up to 0.0514 μg kg−1) have been identified as the proximal cause of indiscriminate fish kills and epornitic mortality of algivorous Phoeniconaias minor (lesser flamingos). With the unequivocal increase in climate change and variability, algal blooms and cyanotoxins will increase in frequency and severity, and this will necessitate swift action towards the mitigation of nutrient-rich pollutants loading into lakes in the region.
