Impacts of algal blooms and microcystins in fish on small-scale fishers in Winam Gulf, Lake Victoria

Implications for Health and Livelihood

Bibliographic Data

ID4761930
AuthorsAmber Roegner (0000-0002-8650-3789, University of Nebraska–Lincoln), Jessica Corman, Jessica R Corman (0000-0002-2633-8080, University of Nebraska–Lincoln), Lewis Sitoki (0000-0002-8137-3890, Technical University of Kenya), Zachary Kwena (0000-0002-5117-5084, Kenya Medical Research Institute), Zachary Ogari (0000-0002-3214-2797, Kenya Fisheries Service), Jared Miruka, Jared Babu Miruka (Kenya Marine and Fisheries Research Institute), Ame Xiong (University of Wisconsin–Milwaukee), Chelsea Weirich (0000-0002-2481-4987, University of Wisconsin–Milwaukee), Christopher Aura, Christopher Mulanda Aura (0000-0001-9590-9652, Kenya Marine and Fisheries Research Institute), Todd Miller (0009-0003-2162-3434), Todd R Miller (0000-0002-2113-1662, University of Wisconsin–Milwaukee)
Year2023
Volume28
Issue1
Publication date2023-01-01
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueConservation Ecology (JOURNAL)
Journal identifiersISSN: 1195-5449 • E-ISSN: 1708-3087
PublisherResilience Alliance (PUBLISHER • CA)
DOI10.5751/es-13860-280149
PMID39669889
OpenAlexW4360972407
LanguageEN
Citations received2
References cited10

Lake Victoria, bordered by Kenya, Tanzania, and Uganda, provides one of the largest freshwater fisheries in the world and supports millions in small-scale fishing communities. Historical environmental change, including population growth, nutrient loading, introduced invasive species, and rising temperatures, has resulted in eutrophication and persistent cyanobacterial harmful algae blooms (cyanoHABs) over recent decades, particularly in the shallower gulfs, bays, and inlets. CyanoHABs impact fisheries and food web dynamics and compromise food and water security for nearshore fisher populations. In this study, we examine the social-ecological impact of freshwater blooms on fisher health in one of these eutrophic regions, Winam Gulf in Lake Victoria. CyanoHABs persist for months and produce microcystins and hepatotoxins at levels unsafe for human health. We assessed potential risk and contribution of microcystin exposure through fish consumption, in addition to exposure through water source, and conducted 400 fisher and 400 household surveys. Average microcystin concentrations exceeded the World Health Organization (WHO) guideline for drinking water consistently during the long dry season, and cyanobacterial cell counts surpassed WHO standards for recreational risk in 84% of samples. Hazard quotients for fish consumed by young children were 5 to 10 times higher than permissible levels. In addition, fishers chronicled profound ecosystem changes with direct impact on livelihood, fisheries, and water quality with 77.4% reporting a decline in profit or catch, 83.1% reporting adverse impacts of cyanoHABs on fish in the lake, and 98.2% reporting indicators of declining water quality in the lake overall. Through the application of a social-ecological lens to a public health model, we identified spheres of influence that modify how fishers experience HABs related stressors and risks to provide a starting point at which to identify sustainable strategies to improve food and water security and livelihood for the millions in nearshore communities

Agriculture · Algal bloom · Biology · Ecosystem · Eutrophication · Fish mortality · Fishery · Fishing · Food security · Freshwater ecosystem · Geography · Nutrient · Overexploitation · Phytoplankton · Water quality · Aquatic Ecosystems and Biodiversity · Aquatic Ecosystems and Phytoplankton Dynamics · Environmental Science · Ecology

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