Lake Chilwa in southern Malawi undergoes periodic drying that severely impacts fisheries, aquatic biodiversity, and the livelihoods of millions. Recovery of the lake fishery depends largely on deep pools in influent rivers, which serve as critical fish refugia during lake recession. These pools are increasingly threatened by environmental degradation, unsustainable irrigation, and poor fishing practices. This study examined the role of deep pools in tributary rivers in maintaining fish biodiversity and supporting fisheries recovery during and after lake drying. Deep pools in the Likangala and Domasi rivers were mapped and assessed for productivity and species diversity between December 2018 and 2019. Baseline water quality data from 2015/16, covering dry and wet seasons at 16 sites, were analysed using standard methods, together with Environmental Water Flow assessments based on a desktop reserve model. Water quality varies by river, season, and channel type, with significantly higher concentrations of most parameters during the dry season. Hydrochemical analysis showed bicarbonate dominance, suggesting mineral denudation driven by CO2-charged runoff as the main controlling process. Clear hydrochemical gradients distinguish deep pools from open channels, confirming deep pools as chemically and biologically distinct habitats. Desktop Reserve Model results indicated that the Domasi River is in better ecological condition, while the Likangala River shows over-commitment of water resources. In both rivers, deep pools maintained fish biodiversity and acted as key refugia and breeding habitats during lake recession through maintenance of water volume at a quality amenable for fish production. However, fish biomass, productivity, and species diversity were significantly higher in Likangala River pools, reflecting their larger size and depth, higher water volumes, and better community-based fisheries management. This shows that favourable ecological conditions alone are insufficient without effective governance. Fish production rose from about 5 000 tonnes before the 2017 recession to a record 42 000 tonnes in 2024. Recovery followed flood-pulse dynamics, enhanced by cyclone-driven nutrient inputs and an extended closed fishing season. Despite this, unregulated water abstraction, catchment degradation, agricultural runoff, weak governance, and invasive species threaten sustainability. Strengthening local management, community awareness, multi-sectoral coordination, and long-term monitoring is essential to sustain fishery resilience under increasing climate variability.

A study was conducted to assess temporal and spatial changes in the trawlable demersal zones of Lake Malawi. Data from surveys conducted in 1998 and 2020 targeting 120 stations covering a surface area of 9647.97 km 2 was used. Trawling speed of Research Vessel Ndunduma was restricted to 4.6 km/hr. Length frequency distribution was modelled with the probability density function for determining the likelihoods in the gamma distribution. Parameters for modal length and logistic modelling were guessed and Solver in Microsoft Excel 2021 was used to generate the best of fit values through iteration with GRG Nonlinear approach. The study determined fish diversity using the Shannon and Weiner relationship. The recent survey recorded fewer fish species (149) against 158 sampled in the previous survey. The overall catch rates in 2020 and 1998 ranged from 3.8 kg/0.5 h to 2003.8 kg/0.5 h and 28.7 kg/0.5 to 1,884.3 kg/0.5 h, respectively. Overall fish density in the 2020 and 1998 surveys was calculated at 11.7 tons/km 2 and 7.5 tons/km 2 , respectively representing a 35.6% drop. The study has revealed temporal and spatial shifts in the fish stock composition, distribution and abundance which necessitates urgent management interventions to prevent further fisheries resource losses. Efforts to regulate mesh sizes of the cod-ends of trawlers are encouraged just like the initiative of introducing a closed season for the commercial operators.

Key fish breeding and other biodiverse areas in Malawian lakes are under threat from illegal fishing, the siltation of key breeding areas (due to deforestation-induced soil erosion), and the clearing of shoreline aquatic vegetation. Freshwater protected areas, also called sanctuaries, have the potential to support the restoration of degraded aquatic environments and protect fisheries’ biodiversity. In Malawi, community-managed fish sanctuaries have been established by beach village committees (BVCs) throughout Lake Malawi, Lake Malombe, Lake Chilwa and Lake Chiuta. The sanctuaries were established to conserve exploited stocks, preserve biodiversity, and enhance fisheries’ yield. The BVCs are aligned with local decentralized village development committees linked to District Councils. Together, they constitute a defragmented decentralized ecosystem-based management of fishery resources. A monitoring study was conducted in sanctuaries in the four lakes during the wet and dry season over three years (2016–2019). The monitoring was carried out to evaluate the sanctuaries’ biological performance. The results showed that community-managed sanctuaries contributed to a 24% increase in the total number of observed species. The Shannon Diversity Index increased from an average 1.21 to 1.52. Small and mid-size (<50 ha) sanctuaries showed a higher performance improvement than large (>50 ha) sanctuaries. This is likely due to multiple factors, including a higher level of fish movement and the greater ability of communities to surveil and enforce smaller sanctuaries. The participation of communities in monitoring enhanced the demonstration effects of sanctuaries. This, in turn, encouraged communities to expand the number and size of the sanctuaries. The biological performance results indicate that community-managed freshwater sanctuaries can be used to protect and restore fish biodiversity in freshwater lakes in Africa. Linking the BVCs to defragmented decentralized structures ensures that the interconnectedness between ecosystem uses, including forestry, agriculture, and tourism, which impinge on fish productivity, are addressed holistically.

This paper presents the findings from a qualitative and quantitative fisheries value chain and post-harvest loss study conducted in four Malawian lakes: Malawi, Malombe, Chilwa and Chiuta. The research found that the estimated total value of the fisheries value chain was US $454 million in 2016 - or 7.2% of the projected 2017 GDP. This is over 2.5 times the previously reported (Government of Malawi, 2017) beach landing site value. The study found that 43%, 54% and 69% of fish have physical and quality losses at the beach, processing and marketing nodes, respectively. However, high quality loss is not proportionately affecting economic loss. The fisheries value chain experiences less than 10% annual economic losses mainly due to low pricing sensitivity of existing products. The overall economic losses are nine percent, being highest at the beach node (19.3%) and smallest at the market node (2.1%). The main reason for this unusual relationship is that pricing is not sensitive to quality, which means that almost all types of quality of product is sold resulting in a recorded relatively low overall physical loss of 4.1%. An important conclusion of the assessment is that even though the economic losses are relatively modest in relation to the total value, the quality losses, which range between 43% and 69% depending on the node, indicate that the potential for health impacts and nutritional value loss are high throughout the value chain. Value chain improvements are recommended to provide economic and nutritional benefits for end-users and value chain actors.

In many developing countries, hydro-meteorological data is scarce due to dysfunctional or non-existent monitoring networks. Where available, such networks are not normally at the desired temporal and spatial scales. Studies in Malawi have shown variations of weather systems at relatively low spatial scales. Such variations, typical of tropical weather, entail a need for increasing the density of the hydro-meteorological monitoring networks for effective monitoring. This study is aimed at improving our understanding of hydro-meteorological processes in the Lake Chilwa Basin, a socio-economically important ecosystem in Malawi with a population of 1.6 million. The study used historical data of rainfall, river discharge and lake levels from old and new monitoring networks installed under the Lake Chilwa Basin Climate Change Adaptation Programme (LCBCCAP). The discharge data were also applied in regionalization to understand the frequency and magnitudes of floods and low flows. The role of Indigenous Knowledge Systems (IKS) in climate change adaptation was investigated through community engagement. The results have shown a declining trend of annual rainfall, river discharge, lake levels and shifts in rainfall onset and cessation. The quantiles of low flows and floods developed in the study can be used in estimating these hydrological extremes in the ungauged parts of the basin. Lastly, a need was identified to validate the various IKS used by the communities with empirical data.

Natural shocks have been common in the Lake Chilwa Basin. In 2010, Malawi experienced El Niño followed by La Niña phenomenon which led to below normal rainfall resulting in droughts and a recession of Lake Chilwa in 2012. Past livelihoods and ecological studies have shown that the Lake Chilwa Basin constitutes a fragile ecosystem based on extreme pressure from deforestation, fires and the periodic desiccations of the lake. However during periods of natural resources scarcity livelihoods tend to be supply-driven based on limited choices. Donor supported projects during these times provide livelihood alternatives from a predetermined menu of activities, rather than exploring the livelihoods alternatives with the people that they intend to support. However, diversification of alternative livelihood sources has helped households in the lake basin to insure themselves from shocks and negative trends of natural resource scarcity as a result of frequent lake recessions and impacts of climate variability. While diversification occurs to ameliorate the riskiness of natural resource-based livelihoods, physical and socio-economic structural adjustments that take place to overcome consumption sufferings created by shocks, are seldom recognised. This chapter therefore explores both project-based livelihood interventions and household responses by recognising 'livelihoods' as being as much about a 'way of life' as they are a means of making a living in the Lake Chilwa Basin following climatic shocks from 2010 during the implementation of the Lake Chilwa Basin Climate Change Adaptation Programme (LCBCCAP).

Complex patterns and processes in aquatic resources are mostly analyzed under the assumption that ecological relationships do not vary within management areas. This assumption was questioned by studying the spatial distribution of the target fish population, Oreochromis karongae (Chambo) from South East Arm (SEA) of Lake Malawi where it is in abundance. Survey data from 2007 is used in the modeling of the spatial distribution. Three models, global logistic regression (GLR), generalized additive logistic model (GAM) and geographically weighted logistic regression (GWR) were run to explore the best model that can understand spatial non-stationarity better and how it affects fish distribution. GWR (AIC = 18.62) model explained significantly more variability than the global models GLR (AIC = 40.84) and GAM (AIC = 40.22). Adjusted R2 explained 62.8% in GWR against 41.4% for GAM model. GWR is a better model than GAMs in understanding the spatial distribution of fish species.

This paper reviews the importance of African lakes and their management challenges. African inland lakes contribute significantly to food security, livelihoods and national economies through direct exploitation of fisheries, water resources for irrigation and hydropower generation. Because of these key contributions, the ecosystem services provided are under significant stress mainly owing to high demand by increasing populations, negative anthropogenic impacts on lake catchments and high levels of poverty which result in unsustainable use. Climate variability exacerbates the stress on these ecosystems. Current research findings show that the lakes cannot sustain further development activities on the scale seen over the past few decades. Millions of people are at risk of losing livelihoods through impacts on livestock and wildlife. The review further shows that the problems facing these lakes are beyond the purview of current management practices. A much better understanding of the interactions and feedbacks between different components of the lake socio-ecological systems is needed to address the complex challenges of managing these ecosystem services. This review suggests that the three small wetlands of Chad, Chilwa and Naivasha provide an opportunity for testing novel ideas that integrate sustainability of natural resource management with livelihoods in order to inform policy on how future land use and climatic variability will affect both food security and the ecosystem services associated with it.

Lake Chilwa, a Ramsar wetland of international importance, is a major source of fish and agricultural produce. As such it is vital for the livelihoods of large numbers of people who live in the surrounding area and also for urban populations in Malawi. The wetland also plays a critical conservation role as it supports a population of 1.5 million residents and non-resident waterfowl, and is both a breeding ground and resting and feeding station along an important bird flyway in Southern Africa. The productivity of the agricultural systems in the wetland depends on adequate rainfall to annually recharge the lake and maintain the water balance in the wetland. When lake levels are high it is one of the most productive lakes in Africa. A number of different management initiatives have been developed to try to balance human and conservation requirements. The last was developed in 2001 but has not been implemented in a holistic manner due to delays in the decentralization of government activities to the district level and lack of funding. This review of the Lake Chilwa management experience suggests the need for more effective decentralized institutional arrangements that fully engage the local communities and stakeholders, and recognize the need for trade-offs in ecosystem services (ESS) in the wetland and the catchment.

Small freshwater pelagic fisheries in closed lakes are very important to millions of people in sub-Saharan Africa providing livelihoods and nutritional security. However, returns from these fisheries have been shown to uctuate in response to climatic variability. In order to understand the impact of these fluctuations on the livelihoods of people dependant on these fisheries, there is a need for information on how the fish value chain is organized and how it functions in response to variation in supplies. The results will feed into strategies that build resilience in fishing households against the uncertainties arising from unstable ecosystems. The Lake Chilwa fishery value chain is composed of fishers, processors, traders, fish transporters, boat owners, owners of fish processing shades, fisheries associations, gear owners, gear makers, firewood sellers, and traders of fishing gear and equipment. The value chain employs many people and local authorities can consider using this information in the design of rural development strategies for employment generation in small-scale fishing communities. The findings from this study have a number of implications for the improvement of the livelihood of fishers and enhancing their capacity to mitigate against the effects of climate change.

Lake Malawi has one of the most diverse fish faunas in the world (500–650 species) and is a major source of protein for the people of Malawi. Chambo (Oreochromis spp.) is one of the most important food fishes; its abundance has declined sharply over the last twenty-years. Surveys by the Malawi Department of Fisheries have shown a decrease in chambo density in the southeast arm of the lake and the annual harvest has dropped substantially since 1985. We conducted a dynamic stock assessment of Oreochromis spp. which included all vessel and gear types and covered the entire southeast arm of Lake Malawi. Chambo biomass peaked in 1982 and then declined continuously through the early 2000s. The biomass is highly correlated with the mean lake height two years prior suggesting that recruitment may be linked to increased nutrient input, and spawning and nursery habitat associated with the flooding of low lying areas. The main driver of chambo biomass, however, was fishing pressure which was above the level that would achieve maximum sustainable yield during the entire time series. This study provides a baseline from which to measure changes due to future management actions or climate variations.

The potential for integrating aquaculture with agriculture has been widely recognized as a means of improving the use of inputs, diversifying output and economic opportunity, and enabling smallholder producers to maintain and strengthen livelihoods. This paper describes the outcomes of this approach and explains the extent to which it has been taken up and has led to sustained and self-generated capacity. Based in particular on experience in Malawi, Ghana and Cameroon, it also considers implications more widely in the region. The overall picture is that this is a partial and still emerging success story, linked as much with the social and economic drivers surrounding smallholder farmers as with the development support approach adopted.

Lake Chilwa is shared by Malawi and Mozambique, it supports an important fishery and its watershed is undergoing rapid population growth and increasing utilization for agricultural production. It is a shallow, closed basin lake with extensive surrounding wetlands; and it has suffered several desiccation events in the last century. To better understand the current condition of the lake, we monitored a suite of physical, chemical and biological parameters at approximately monthly intervals over an annual cycle in 2004–2005. The limnology of the lake was extremely sensitive to seasonal changes in the lake's seasonal hydrological cycle. The physico-chemical parameters, temperature, electrical conductivity, and total suspended solids exhibited clear seasonal patterns driven by the highly seasonal rainfall and resultant lake levels. In response, phytoplankton and zooplankton abundance, as well as biologically dependent oxygen concentrations and pH, exhibited several maxima levels over the year. The peaks of phytoplankton and zooplankton were out of phase suggesting a lag in the zooplankton grazing in response to pulses in primary productivity. Chlorophyll concentrations can exceed 1mg/L in surface waters indicative of hypereutrophic conditions, but they fell dramatically during zooplankton peaks. This hydrologically driven, shallow and mesohaline lake is a productive and critical resource to the region. Its management poses challenges arising from the dependence of its limnology and fishery on the lakes hydrology, catchment land use and climate variability.

This paper reviews the management challenges facing Malawi lakes and analyzes the management responses that have been developed to deal with these challenges. Malawi lakes are under considerable stress due to high population growth and increasing levels of poverty which have led to overexploitation of fishery resources. High rates of soil erosion in the lake catchments are increasing siltation of shallow lakes, deltas and embayments, affecting water quality and fish breeding habitats, thereby degrading fish production potential. This review further shows that past and current management approaches have focused on maximizing sustainable yield and have failed to adequately incorporate socio-ecological factors and broader lake catchment processes into fisheries management plans. This, in turn, led to the top-down development of fisheries laws and technical regulations which were difficult to enforce, increased conflict between resource users and fisheries managers, and failed to control fisheries over-exploitation and the collapse of the chambo (tilapia) and cyprinid fisheries. The paper recommends that the fisheries policy should be reviewed to focus on resilience of fisheries, environment and livelihoods. Policy makers should adopt integrated management planning to address the diverse interest of stakeholders in lake basins, as well as the ecological, socio-economic and external factors threatening sustainability of lake ecosystems and livelihoods of dependent communities.