The extent of cage aquaculture, adherence to best practices and reflections for sustainable aquaculture on African inland waters

Musinguzi, Laban; Lugya, Jessy; Rwezawula, Philip; Kamya, Ashraf; Nuwahereza, Colleb; Halafo, Jose; Kamondo, Stephanie; Njaya, Friday; Aura, Christopher Mulanda; Shoko, Amon Paul; Osinde, Robert; Natugonza, Vianny; Ogutu‐Ohwayo, R.

doi:10.1016/j.jglr.2019.09.011

Cited by 54 publications

(34 citation statements)

References 16 publications

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“…The present study was conducted before the onset of cage culture in the Kenyan portion of Lake Victoria. Recent reports, however, indicate that non‐adherence to best aquacultural practices, including setting cages in close proximity around protected areas, eutrophic and hypereutrophic waters, shallow water bodies and sites of <5 m average water depth, and being to the shoreline (Musinguzi et al., 2019) are among the challenges facing sustainable aquaculture. Continuous monitoring of the ecosystem is of paramount importance to avert such potential impacts on water quality attributable to the rapid expansion in cage numbers.…”

Section: Discussionmentioning

confidence: 99%

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Spatio‐temporal trends of nutrients and physico‐chemical parameters on lake ecosystem and fisheries prior to onset of cage farming and re‐opening of the Mbita passage in the Nyanza Gulf of Lake Victoria

et al. 2020

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Many large lake ecosystems are experiencing increasing eutrophication and persistent cyanobacteria‐dominated algal blooms affecting their water quality and ecosystem productivity because of widespread non‐point and point nutrient sources. Accordingly, the present study utilized data of July 2003 and January–February 2004, as well as previous measurements of nutrients and physico‐chemical variables (electrical conductivity, dissolved oxygen, temperature, pH, turbidity and chlorophyll‐a), to characterize the spatial and temporal trends, as a means of better understanding the factors influencing lake environmental conditions, as support tools for long‐term ecosystem management and for better understanding the long‐term trends and effects. Inshore gulf areas were found to represent zones of maximum nutrient concentrations, compared to the deep main lake zones, with significant inter‐parameter correlations. Phosphorus, silicon and chlorophyll‐a concentrations were significantly correlated. Water electrical conductivity was also significantly and positively correlated with soluble reactive silicon (SRSi), alkalinity hardness DO, while exhibiting a negative association with water transparency. Water turbidity and transparency, electrical conductivity, and SRSi concentrations clearly describe a gradient from the gulf into the main lake. For such a shallow gulf, these findings suggest primary productivity is influenced mainly by the availability of nutrients, light transparency and the extent of availability of resuspended nutrients. The increasing eutrophic state of Lake Victoria is a serious concern since it contributes to an increased potential of more frequent occurrences of cyanobacterial blooms, a potential public health risk to both humans and wildlife. Improved understanding of influences from previous fish species introductions and concomitant changes in indigenous fish species, increased lake basin population and anthropogenic activities, water hyacinth resurgences, sustainability of biodiversity, and current interests in cage farming, are among the major concerns and challenges facing the contemporary Lake Victoria. The trends regarding nutrients and physico‐chemical characteristics are intended to support better monitoring efforts and data to promote the lake's ecosystem services and the sustainable management of the lake ecosystem.

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Section: Discussionmentioning

confidence: 99%

“…Recent studies indicate an increasing number of fish cages (Aura et al., 2018; Hamilton et al., 2020; Njiru, Aura, & Okechi, 2018). There also are growing concerns regarding the water quality around those areas attributable to non‐adherence to best practices in cage fish farming (Musinguzi et al., 2019).…”

Section: Introductionmentioning

confidence: 99%

Spatio‐temporal trends of nutrients and physico‐chemical parameters on lake ecosystem and fisheries prior to onset of cage farming and re‐opening of the Mbita passage in the Nyanza Gulf of Lake Victoria

et al. 2020

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“…The influence of water level fluctuations on fisheries production has been widely studied in rivers, lakes and reservoirs ( Welcomme, 1970 , Hamerlynck et al, 2011 , Kolding et al, 2016 ). These changes tend to affect productivity and the timing and area of breeding, food availability, catchability, expansion of shallow productive inshore areas, cage culture establishments ( Kolding and van Zwieten, 2012 , Gownaris et al, 2015 , Musinguzi et al, 2019 ). Studies on Lakes Chad, Mweru, Mweru wa Ntipa and Chilwa reported variation in yield and species composition with lake level ( Lévêque, 1995 , Kolding et al, 2016 ).…”

Section: Introductionmentioning

confidence: 99%

Consequences of calamities and their management: The case of COVID-19 pandemic and flooding on inland capture fisheries in Kenya

Aura

Nyamweya

Odoli

et al. 2020

Journal of Great Lakes Research

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During the period February to June 2020, heavy rainfall caused increases in levels and flooding in many lakes in East Africa. This coincided with the COVID-19 pandemic. These calamities affected ecosystems and livelihoods, especially of fishers who depend on fisheries as their only source of livelihood. This study examined the effects of COVID-19 and flooding on the major inland capture fisheries in Kenya to illustrate the effect of such calamities on vulnerable communities to guide interventions. Socioeconomic data were collected across the fish value chains during the peak of COVID-19 pandemic and flooding in Kenya from May to early June 2020. The measures put in place to contain COVID-19 pandemic notably dusk to dawn curfew (66%) and lock-downs (28%) in major cities that act as main fish markets were cited as the main factors that influenced fishing and fishing trade. Negative consequences reported included livelihood losses from the COVID-19 pandemic. Reduced fishing time and trips as well as a decline in consumables such as boat fuel resulted in low fish catches. Although COVID-19 pandemic affected livelihoods, the fish stocks benefited from reduction in fishing effort. Similarly flooding led to livelihood and material losses but positively impacted on stocks through expansion of fish breeding and nursery areas. The respondents recommended that governments should have disaster preparedness programs in place to address such calamities. There is also need for more detailed research on calamities that are increasing in frequency to provide information and data to guide policy and interventions.

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“…In addition to the changes occurring in capture fisheries, the recent increases in cage culture farms in the B&Gs (Aura et al, 2018;Opiyo et al, 2018;Musinguzi et al, 2019) constitutes an additional threat for the lake. It is well known that aquaculture can contribute significantly to the nutrient enrichment of freshwater ecosystems (Zhang et al, 2006).…”

Section: Other Processes Involved In the Increasing Occurrence Of Cyamentioning

confidence: 99%

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

et al. 2020

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Africa is experiencing high annual population growth in its major river basins. This growth has resulted in significant land use change and pollution pressure 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. However, Lake Victoria (LV) experienced a progressive eutrophication and substantial changes in the fish community leading to recurrent proliferation of water hyacinth and cyanobacteria. Based on an extensive literature review, we show that cyanobacterial biomasses and microcystin concentrations are higher in the bays and gulfs (B&Gs) than in the open lake (OL), with Microcystis and Dolichospermum as the dominant genera. These differences between the B&Gs and the OL are due to differences in their hydrological conditions and in the origins, type and quantities of nutrients. Using data from the literature, in this paper we describe the multiple ways in which the human population growth in the LV watershed is connected to the increasing occurrence of cyanobacterial blooms in the OL and B&Gs. We also described the already documented consequences of cyanobacterial blooms on food resources and fishing and on direct water use and water supply of local populations, with their potential consequences on the human health. Finally, we discuss the actions that have been taken for the protection of LV. Although many projects have been implemented in the 15 past years in order to improve the management of waste waters or to reduce deforestation and erosion, the huge challenge of the reduction of cyanobacterial blooms in LV by the control of eutrophication seems far from being achieved.

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The extent of cage aquaculture, adherence to best practices and reflections for sustainable aquaculture on African inland waters

Cited by 54 publications

References 16 publications

Spatio‐temporal trends of nutrients and physico‐chemical parameters on lake ecosystem and fisheries prior to onset of cage farming and re‐opening of the Mbita passage in the Nyanza Gulf of Lake Victoria

Spatio‐temporal trends of nutrients and physico‐chemical parameters on lake ecosystem and fisheries prior to onset of cage farming and re‐opening of the Mbita passage in the Nyanza Gulf of Lake Victoria

Consequences of calamities and their management: The case of COVID-19 pandemic and flooding on inland capture fisheries in Kenya

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

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