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Aquatic foods are critical for food and nutrition security in Malawi, but it is unclear which populations benefit from different aquatic foods and what factors shape food access. Spatial analysis of food flows across value chains from Lake Malawi to domestic consumers shows that usipa (Engraulicypris sardella) reaches more consumers than chambo (Oreochromis karongae) across all Malawi districts, particularly rural populations. Higher number of markets, nutrient content, and overall supply coupled with lower retail prices and volumes make usipa more accessible to consumers than chambo. Spatial analysis of food flows can guide policymakers towards supporting fisheries that reach vulnerable populations and designing interventions that enhance physical and economic access to fish.

This study assessed zooplankton density and Chl-a amount to understand their spatial and seasonal variation in Lake Malombe. Samples were collected for analysis during the hot, dry season (HDS) and cool, dry, windy season (CDWS). The zooplankton identified were Tropodiaptomus cunningtoni (TC), Mesocyclops aequatorialis aequatorialis (MAA), Thermocyclops neglectus (TN), Bosmina longirostris (BL), Diaphanosoma spp. (DS), and Nauplii. These zooplankton groups belong to copepods, Cyclopidae, Cladocera, Ctenopod, and Rotifers. Chl-a exhibited a substantial seasonal variation, with the highest concentration observed in HDS and lowest in CDWS. Zooplankton such as T. cunningtoni, M. aeq. aequatorialis, T. neglectus, B. longirostris, Diaphanosoma spp, Nauplii, and Rotifer increased during the HDS. The water temperatures (WT), pH, Dissolved Oxygen (DO), and Chl-a positively correlated with all zooplankton densities. Sodium (Na+) and Potassium (K+) ions positively correlated with TC, MAA, DS, Nauplii, and Rotifers. Chloride ion (Cl-) positively correlated with DS, Rotifers, while Carbonate ion (CO32-) positively correlated with TC. Bicarbonate (HCO3-) correlated positively with DS and Rotifers, while TDS correlated negatively with BL, Nauplii, and Rotifers. Nitrite affected zooplankton density negatively, while SRP had a positive effect. The study revealed that physical-chemical variables, some significant ions, and Chl-a are the most critical factors influencing the spatial and seasonal variation of zooplankton density in the lake. These findings demonstrate the interaction between physical-chemical variables, Chl-a, and zooplankton and highlight the significance of ecological understanding of the complex dynamics of the food web system in shallow tropical lakes such as Lake Malombe- under the changing climate.

Using multiple data collection approaches, this study demonstrates that current Lake Malombe fish stock fluctuation instigated by socio-economic and environmental conditions significantly impacts the lake ecosystem. The top-down management approach would not solve complexities that underlie human-induced fluctuations. The study further established that previous management approaches undermined the fact that fisherfolks have evolved to cope with the fluctuations. Therefore, the study recommends policy reforms, focusing on fisherfolks' evolution and alternative livelihood options.

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 9,647.97km2 was used. Trawling speed of Research Vessel Ndunduma was restricted to 4.6km/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 3.8kg/0.5hr to 2003.8kg/0.5hr and 28.7 kg/0.5 to 1,884.3 kg/0.5hr, respectively. Overall fish density in the 2020 and 1998 surveys was calculated at 11.7tons/km2 and 7.5tons/km2, 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.

Inland fisheries make substantial contributions to food security and livelihoods locally, regionally, and globally but their conservation and management have been largely overlooked by policy makers. In an effort to remedy this limited recognition, a cross-sectoral community of scientists, practitioners, and policy makers from around the world convened a high-level meeting in 2015 at the Food and Agriculture Organization of the United Nations headquarters in Rome, Italy to develop recommendations for sustainable inland fisheries management. This meeting resulted in the production of the Rome Declaration, outlining ten key steps needed to achieve responsible inland fisheries. When the Ten Steps were conceived, they were framed in a global context because inland fisheries around the world face similar challenges, and it was hoped that these large-scale and ambitious steps would draw the attention of regional or international bodies for greater investment in their proper management. Most inland fisheries, however, are managed at a local (often community, watershed, or waterbody) scale with the "on-the-ground" practitioners, managers, assessment biologists, and stewardship officers responsible for achieving the promise of the Ten Steps. Here, we reflect on the relevance of the Ten Steps to practitioners using six regional case studies from around the globe (North America, South America, Europe, Asia, Australia, and Africa) to identify the extent to which existing efforts align with the Ten Steps and where there are opportunities to do more. Learning what is effective from local/regional actions should better inform a more global "action plan" and provide tangible guidance for implementation recognizing that global guidance needs to be informed by and acted upon by local practitioners. We conclude by considering the common challenges, synergies, and other emergent properties that arise from these case studies, and use these as a path forward to advancing responsible management of inland fisheries through the Rome Declaration. Of particular importance is the need to balance the high-level aspirational goals of the Ten Steps with the local cultural, socio-economic, and institutional realities that ultimately influence how humans interact with fisheries resources and aquatic ecosystems. This assessment provides valuable information on how to refine and implement the Ten Steps recognizing that success will require coordinated efforts among on-the-ground practitioners, scientists, stakeholders, rightsholders and international decision makers. Natural Sciences and Engineering Research Council of Canada; Genome Canada; Fonds de recherche du Quebec -Nature et Technologies grant from the Government of Quebec, Canada; Danish Rod and Net Fishing License Funds Published version Natural Sciences and Engineering Research Council of Canada(Natural Sciences and Engineering Research Council of Canada (NSERC)CGIAR); Genome Canada(Genome Canada); Fonds de recherche du Quebec -Nature et Technologies grant from the Government of Quebec, Canada; Danish Rod and Net Fishing License Funds Public domain – authored by a U.S. government employee

This paper explores the impact of the COVID-19 pandemic and the measures to mitigate it on gender dynamics and power relations among men and women involved in cross border fish trade in Zambia and Malawi and the ensuing policy implications to support the fisheries value chain. The paper is based on qualitative and quantitative data collected in Zambia and Malawi in October and November 2021. We conducted quantitative surveys implemented the Cognitive Edge Sensemaker Tool and the Emergency Market Mapping and Analysis toolkit (EMMA to understand the dynamics of cross border fish trade before and during the COVID-19 pandemic. A social relations approach, focusing on gender relations, was used to analyze the data. Findings suggest that women cross-border fish traders are caught up in a complex web of networks and relationships that are disempowering to them. Some measures put in place to mitigate the impact of the COVID-19 pandemic lacked an understanding of the historical perspective and dynamics of women in fish trading communities further marginalizing men and women cross border fish traders. Some measures exacerbated hidden violence against women and overt forms of violence against men. Since most of the violence occur across state boundaries, there is a need for inter-country coordination to ensure that the rights of women and men cross border fish traders are protected. Policy measures could include educating police officers for even-handedness when enforcing COVID-19 rules and providing mechanisms for reporting abusive practices.

A thriving black-market economy of scam scholarly publishing, typically referred to as ‘predatory publishing,’ threatens the quality of scientific literature globally. The scammers publish research with minimal or no peer review and are motivated by article processing charges and not the advancement of scholarship. Authors involved in this scam are either duped or willingly taking advantage of the low rejection rates and quick publication process. Geographic analysis of the origin of predatory journal articles indicates that they predominantly come from developing countries. Consequently, most universities in developing countries operate blacklists of deceptive journals to deter faculty from submitting to predatory publishers. The present article discusses blacklisting and, conversely, whitelisting of legitimate journals as options of deterrence. Specifically, the article provides a critical evaluation of the two approaches by explaining how they work and comparing their pros and cons to inform a decision about which is the better deterrent.

Valuation of environmental goods and services has an important role to play in the protection and conservation of riverine resources. However, the literature shows a dearth of information regarding factors that influence people’s willingness to pay (WTP) for riverine resources. This research study was undertaken to find out key factors that affect the willingness of people to pay for the conservation of aquatic resources in the lower section of the Linthipe River in Malawi. Data was collected through household interviews, focus group discussions, key informant interviews, and contingent valuation (CV) surveys. The study noted that communities were willing to offer $3.51 per year for the conservation of aquatic resources in the river. This study established that the people’s WTP is a function of education level, household usage of the goods and services, community support in the management of the resources, household income, and distance of the household from the river ecosystem. The study further discovered that the pay-out level of the users along the Linthipe River was driven by household usage of resources from the river, period of stay in the area, and level of household income. Our recommendation is that government and development partners should popularize the important role played by rivers and streams to surrounding communities and beyond to appeal for more support from users. The authorities must further empower the communities along the rivers and streams to sustainably manage the aquatic resources for the continued appreciation of aquatic resources by future generations.

This study assessed plankton density and biomass in an attempt to better understand their spatial and seasonal variation in Lake Malombe. Samples were collected for analysis during the hot dry season (HDS) and cool dry windy season (CDWS). The zooplankton identified were T. cunningtoni (TC), M. aEq. Aequatorialis (MAA), T. neglectus (TN), Bosmina longirostris (BL), Diaphanosoma spp (DS), Nauplii, and Rotifer. These zooplankton groups belong to copepods, Cyclopidae, Cladocera, Ctenopod, and Rotifers. The phytoplankton biomass exhibited a strong seasonal variation with the highest value observed in HDS and lowest in CDWS. Zooplankton such as T. cunningtoni, M. aEq. Aequatorialis, T. neglectus, Bosmina longirostris, Diaphanosoma spp, Nauplii, and Rotifer were dominant during the HDS. The WT, pH, and DO, Chlo-a positively correlated with all zooplankton groups. The Na+ and K+ positively correlated with TC, MAA, DS, Nauplii, and Rotifers. The Cl− positively correlated with DS, Rotifers while, CO32− positively correlated with TC. HCO3− correlated with DS and Rotifers positively while TDS correlated with BL, Nauplii, and Rotifers negatively. Nitrite affected all zooplankton groups negatively while SRP had a positive effect on all zooplankton density. The study revealed that physical-chemical variables, some major ions, and Chlo-a are the most important factors influencing the spatial and seasonal variation of zooplankton density in the lake. These findings demonstrate the interaction between physical-chemical variables, phytoplankton, and zooplankton and highlight the significance of ecological understanding of the complex dynamics of food web system in tropical shallow lakes - under the changing climate.

Lake Malombe is endowed with a variety of ecosystem services (ES) that have a considerable economic value. This study used, a combination of market-based and value transfer techniques to evaluate the lake ES. The results showed that the annual economic value of Lake Malombe ES is estimated at US$ 40.68million, equivalent to US$635.63/hh/yr. The ecosystem provisioning service (EPS) is ranked the highest (87.45%) in terms of contribution, followed by biodiversity (8.64%), flood regulation (3.70%) then carbon sequestration, culture, and aesthetic services. The ES quality index ranks culture and aesthetic services as the lowest suggesting that investment in the tourism industry in Lake Malombe is not much advanced. Although this study did not take into account all ES components such as non-use values and other regulatory services, the estimated total annual ES value of US$ 40.68million derived from Lake Malombe provides a strong basis for a need to design an economic incentive model to encourage the local communities to take responsibility for managing the lake. Any decline in the supply of ES can eventually worsen poverty and push the local population to desperately over depend on EPS and degrade even the areas deemed to be conserved for future generations thereby creating a vicious circle of poverty and ecosystem disservices. This study provides a significant insight into the trade-offs between ES and diverse stakeholders. Balancing the interest of local communities given the importance of EPS in sustaining their livelihoods and that of global communities is required to effectively manage the lake.

Forecasting, using time series data, has become the most relevant and effective tool for fisheries stock assessment. Autoregressive integrated moving average (ARIMA) modeling has been commonly used to predict the general trend for fish landings with increased reliability and precision. In this paper, ARIMA models were applied to predict Lake Malombe annual fish landings and catch per unit effort (CPUE). The annual fish landings and CPUE trends were first observed and both were non-stationary. The first-order differencing was applied to transform the non-stationary data into stationary. Autocorrelation functions (AC), partial autocorrelation function (PAC), Akaike information criterion (AIC), Bayesian information criterion (BIC), square root of the mean square error (RMSE), the mean absolute error (MAE), percentage standard error of prediction (SEP), average relative variance (ARV), Gaussian maximum likelihood estimation (GMLE) algorithm, efficiency coefficient (E2), coefficient of determination (R2), and persistent index (PI) were estimated, which led to the identification and construction of ARIMA models, suitable in explaining the time series and forecasting. According to the measures of forecasting accuracy, the best forecasting models for fish landings and CPUE were ARIMA (0,1,1) and ARIMA (0,1,0). These models had the lowest values AIC, BIC, RMSE, MAE, SEP, ARV. The models further displayed the highest values of GMLE, PI, R2, and E2. The “auto. arima ()” command in R version 3.6.3 further displayed ARIMA (0,1,1) and ARIMA (0,1,0) as the best. The selected models satisfactorily forecasted the fish landings of 2725.243 metric tons and CPUE of 0.097 kg/h by 2024.

Lake Malombe supports various ecosystem services (ESs). However, it is increasingly experiencing human-induced pressure. This study used geospatial, household surveys, focus group discussion, key i...

Lake Malombe ecosystem provides a vast range of services that are vital for the sustenance of the riparian communities. Understanding land use and land cover (LULC) dynamics, as well as the associated impacts on the multiple ecosystem service value (ESV), is extremely important in decision-making processes and effective implementation of an ecosystem-based management approach. This study analyzed the LULC dynamics from 1989 to 2019. The primary objective of the study was to assess its impact on ecosystem services (ES). The ESV was determined using LULC analysis and established global ESV coefficient. The LULC analysis showed a reduction in forest cover by 84.73% during the study period. Built-up, cultivated land, bare land, shrubs, and grassland increased considerably. Rapid population growth, climate change, government policy conflicts, and poverty were identified as the most important drivers of LULC dynamics. Based on ESVs estimations, the ES changes instigated by LULC dynamics in the study area result in an average loss of US$45.58 million during the study period. Within the same period, the lake fishery also recorded a net loss of US$8.63 million. The highest net loss of US$79.832 million was recorded from 1999 to 2019 due to increased loss of forest, a decrease in water bodies and marsh areas. The sensitivity analysis (CS) indicated that our estimates were relatively robust. This study findings provide a piece of empirical evidence that LULC dynamics in the Lake Malombe catchment have led to a significant loss of ESVs, with serious implications for the livelihoods of the local population.

Lake Malombe fish stocks have been depleted by chronic overfishing. Various management approaches (co-management, command control, and ecosystem-based management to fisheries) have been used to manage the fishery. However, the lack of an accurate predictive model has hampered their success. Therefore, we developed and tested a time series model for Lake Malombe fishery. The seasonal fish biomass and CPUE trends were first observed and both were non-stationary. The second-order differencing was applied to transform the non-stationary data into stationary. Autocorrelation functions (AC), partial autocorrelation function (PAC), and Akaike information criterion (AIC) were estimated, which led to the identification and construction of autoregressive integrated moving average (ARIMA) models, suitable in explaining the time series and forecasting. The results showed that ARIMA (1,2,1) provided a better prediction than its counterparts. The model satisfactorily predicted that by 2032, both fish biomass and CPUE will decrease to 3204.6 tons and 59.672 respectively, signifying the potential threat to Lake Malombe fishery. The model justified the necessity of taking precautionary measures to avoid the total collapse of the fishery.

Lake Malawi continues experiencing serious depletion of most valuable fish species. Presently, commercial and artisanal fishery are forced to target less valuable fish species. Evidently, economic importance of Engraulicypris sardella in Malawi cannot be negated as it currently contributes over 70% of the total annual landings. However, such highest contribution could be a sign of harvesting pressure. Therefore, as the species continues being increasingly exploited, the development of scientific understanding through application of stochastic models is particularly relevant for present and future policy making and formulation of strategies to sustain the resource in the lake. Thus, the study was designed to forecast the annual catch trend of E. sardella from Lake Malawi. The study used time series data from 1976 to 2015 period obtained from Monkey Bay Fisheries Research Station of the Malawi Fisheries Department. The study adopted Box-Jenkins procedures to identify appropriate Autoregressive Integrated Moving Average (ARIMA) model, estimate parameters in ARIMA model and conducting diagnostic check. The study findings showed that ARIMA (2,1,1) model had least Normalized Bayesian Information Criterion (NBIC) value making it a appropriate model for the study. ARIMA (2,1,1) model showed that E. sardella annual catches are positively fluctuating. Again, the model predicted that E. sardella annual catches from Lake Malawi will increase from the annual total landings of 71,778.47 metric tons to 104,261.20 metric tons in the next 10 years (ceteris paribus). Key words: Box-Jenkins, Engraulicypris sardella, Lake Malawi, autoregressive integrated moving average (ARIMA), Modelling, Usipa, Stochastic.

The reproductive biology and size structure was determined for Lethrinops gossei, one of the most abundant fish species contributing 26% of the catch in the demersal trawl fishery of the Southeast Arm of Lake Malaŵi. Breeding seasonality was analyzed on the basis of monthly variation of gonado-somatic index and gonadal appearance, while sexual maturity was determined by fitting the logistic model to the proportions of sexually mature individuals. Length frequency data were used to characterize size structure of the population and to derive a selection ogive for the species based on the currently used cod-end mesh size of 38 mm in the fishery. Results suggest that even though mature individuals were encountered all year round, the main breeding events for L. gossei occur in March and September. It was also determined that the size at which 50% of female L. gossei reached maturity (L50%) was 137 mm total length, while 100% sexual maturity was reached at 170 mm total length. The size at first maturity was 122 mm total length, while the steepness parameter of the maturity ogive, (δ) was 7 mm. Distribution of sizes in the sample was roughly symmetric about a mean of 145 mm total length, while the size at 50% selection was 120 mm total length. These results are discussed in the context of their implications on the management of the demersal trawl fishery in the Southeast Arm currently dominated by L. gossei, given the misalignment of the closed season currently in October to December and the inadequacy of the cod-end mesh size of 38 mm. The main conclusion of this study was that the current cod-end mesh size in the fishery is too small and should be adjusted to prevent growth overfishing. A proposal is made for a closed season for the trawl fishery from March to April.

Fisheries management continues to be a nightmare due to over exploitation of fish stocks and various anthropogenic activities resulting in a reduction of genetic resources. Opsaridium microlepis, a commercially exploited fish species from Lake Malawi, is no exception, hence it is listed among as endangered species. Opsaridium microlepis stocks from four different rivers, were analyzed using 13 geometric morphometric landmarks and 20 microsatellite loci, to determine if the stocks were morphologically and/or genetically different. AMOVA performed on DNA data revealed a significant (P < 0.001) genetic differentiation with 16.4% of the total genetic variance ascribed to differences among populations, and 83.6% due to differences within population. This finding was supported by higher pairwise FST values (FST = 0.17). MANOVA of morphological data showed significant body shape variation among the stocks (Wilk’s λ = 0.0913; P < 0.0001). Pairwise comparisons using both methods indicated that all pairs were significantly different, except morphologically for Bua and Linthipe (P=0.3311). The morphological differences observed consisted of shorter gape and shorter head were thatof the Bua/Linthipe stock was seen in the North Rukuru and Dwangwa stocks. The morpho-genetic differentiation revealed in this study implies that the populations are distinct and should be considered as separate management and conservation units. Key words: Lake Malawi, Mpasa, procrustes distance, genetic differentiation, endangered species, fish stocks, conservation.

This paper presents a case study from Lake Malombe, Malawi. It demonstrates Lake Malombe fish stock fluctuation and its implications on fishing community livelihoods. The main challenges that fishing communities are confronted with and their adaptation strategies developed over the years. This study’s findings suggest that Lake Malombe riparian communities are not regarded as vulnerable so long as they have access to fishing. Fishing supports their livelihood, but declining catches and other factors (siltation of the lake, climate change (heavy rain, drought, and heavy wind), increased mud in the Lake (IML), and lake level fluctuation) beyond their control also expose them to risks and vulnerability. The strategies on how they have survived over the years from the shocks and stress triggered by the decline in fish stocks from the lake are not sustainable in the face of increased human pressures and other environmental drivers. Therefore, an effort towards the governance of the complex socio-ecological systems in which fishery is embedded is required to understand the conditions that define fishers' adaptation strategies. The study further recommends that a combination of coping strategies should be developed to define the fishing communities' level of adaptive capacity and create flexible socio-economic conditions within fishing communities to generate a robust system that can deal with stress.

It is the wish of every stakeholder to see that donor supported structures such as community-based advocacy groups (CBAGs) continue to operate beyond donor support. Various studies show that donor-initiated structures which are often instituted at huge costs experience difficulties with regards to sustainability. This is because such structures reportedly cease to operate after their initial funding runs out resulting into wastage of human and financial resources that could have been invested effectively. However, there is dearth of information regarding the extent to which donor-initiated advocacy groups continue to serve the grassroots, years after phasing out of the donor support. The present study investigated the sustainability of CBAGs, taking a case of advocacy groups initiated and supported by DanChurchAid (DCA) in Malawi. Specifically, the study identified key factors that influence continued operation of CBAGs after years of donor cessation. A combination of quantitative and qualitative approaches was used to collect data from 226 respondents and 16 CBAGs sampled from Karonga, Dowa, Lilongwe, Mwanza and Neno districts from May to June 2020. Secondary data provided preliminary information and cross-validation of information. Descriptive statistics, logit regression and Critical Content Analysis were used to analyze the data. The study identified nine factors that are essential for continued operation of CBAGs namely age of the respondent, marital status of respondent, responsiveness of duty bearers, availability of basic systems and procedures, unity among members, community contribution, linkages and networking, fundraising skills, and availability of exit strategy. It was also noted that need to end corruption, increased prevalence of community problems, and expectation for future benefits were key motivators for members to continue serving in the CBAGs, years after donor support. The study recommends the need to encourage supporting organisations to develop exit strategies which would help to concretize the phasing out plan for supporting the CBAGs. Donors and well-wishers should consider investing in the weak institutional areas of the CBAGs such as organization registration, fundraising and organization systems and procedures which are critical to the institutionalization of the CBAGs. Finally, supporting organisations should design integrated advocacy interventions that achieves advocacy agenda without compromising the personal needs of the CBAGs members. This would require supporting the members with livelihoods activities which will in turn offer immediate needs as the members pursue advocacy work.

The hatching period and the growth of Malawian cyprinid Engraulicypris sardella larvae and juveniles collected from two sites along the southwestern shoreline of Lake Malawi were investigated using otolith increment information. The lapillus was used to determine the age in days following previous studies. The hatching months of fish estimated on the basis of lapillus increment counts were from November to July (nine months of a year), demonstrating that this species had an extended spawning season. Based on the age analysis, the fish were separated into two hatching groups: fish that hatched in the rainy season and those that hatched in the dry season. The growth rate of the former (0.70 mm TL per day) was significantly higher than the latter (0.52 mm TL per day). This growth difference was considered to be due to water temperature in the lake.Keywords: Engraulicypris sardella larvae and juveniles, lapillus increments, growth, spawning season, Lake Malawi

Studies were carried out to determine the genetic diversity and structure of endangered Opsaridium microlepis (Mpasa) populations in the affluent rivers of Lake Malawi; Linthipe, Bua, Dwangwa and North Rukuru. A total of 200 DNA samples of O. microlepis from four river populations were analyzed at 20 microsatellite loci. The primers’ discriminating power was high (mean PIC, 0.76) yielding a total of 295 alleles with a range of 10-22 and an average of 15 alleles per locus. All the populations were not in Hardy Weinberg Equilibrium probably due to outbreeding that leads to heterozygosity excess. This observation was further supported by heterozygosity excess exhibited by 100% of the population-locus combinations (mean F IS , -0.30) and lack of evidence for genetic bottleneck. The populations exhibited high genetic diversity as evidenced by high mean Shannon information Index (I=1.64) and high observed heterozygosity (H o = 0.98). Genetic relationships among the populations appear to be less influenced by geographical distance (Mantel’s statistics Z, 0.18; p = 0.6369) implying that the populations do not fit into the isolation by distance model. Nevertheless, the populations are highly differentiated (F ST = 0.17; AMOVA among populations = 16%). This is supported by inter-deme migration of less than one individual per generation ( Nm =0.91) as determined by Slatkin’ private allele method. Therefore, these populations are probably still large and distinct requiring separate monitoring and management due to inferred restricted gene flow and considerable population differentiation. Keywords: Mpasa, Lake Malawi, population structure, genetic diversity, microsatellites, threatened species, conservation.

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 1 mg/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.

Given that fish and fishery products are ranked among the most traded food commodities globally, with developing countries accounting for the bulk of the world’s fish exports, the analysis of fish trade flows is of key importance for any policy measure in the fisheries sector. This study evaluates the determinants of fish trade flows by applying the generalized gravity model. Using panel data covering a period of 14 years for 54 African countries, the gravity model is estimated using the Tobit regression to overcome estimation challenges in the presence of zero trade observations. The results suggest that a 1% increase in exporters’ GDP, importers’ GDP, population, exporters’ fish production, and countries sharing a common border increased fish trade flows by 8%, 14 %, 4%, 36% and 60%, respectively. On the other hand, importers’ fish production, and distance reduced fish trade flows by 5% and 17%, respectively. The results further shows that the belonging to ECOWAS, EAC, SADC and AMU has significantly enhanced intra-fish trade flows thereby contributing to gross trade creation for fish. The results indicate that the current demand for fish is very high such that current production is unable to meet the consumption needs. This calls for consolidated efforts in investment and development of the aquaculture sector as an alternative to the dwindling fish supplies from the wild environment. The findings also demonstrate the need for regional blocs to improve the transport networks on the continent by, among others, adopting a regional cooperation strategy centered on infrastructure development.

Size-at-50% maturity, age and growth, of Oreochromis (Nyasalapia) karongae (‘chambo\') in Lakes Malawi and Malombe were studied. Oreochromis karongae , a major component of the chambo species flock, attained 50% maturity at 225 mm TL in Lake Malawi and at 203 mm in Lake Malombe. The estimated age-at-50% maturity was 2.19 and 1.49 years in Lakes Malawi and Malombe, respectively. Estimated growth parameters for populations at Karonga, Nkhotakota, Salima and Mangochi in Lake Malawi, and for that in Lake Malombe were L ∞ = 328, 319, 308, 388, and 314 mm TL, respectively; and K-values were 0.31, 0.29, 0.34, 0.20 and 0.35, respectively. Similar size-at-50% maturity and growth patterns (age, L ∞ and K-values) were found for O. karongae populations in Lake Malawi, but differences were observed for Lake Malombe populations, suggesting that the current chambo fisheries management regulations, based on findings from the southern part of Lake Malawi, may be applicable to the central and southern parts of that lake, but may not be applicable to Lake Malombe. Keywords: artisanal fishers, chambo fishery, closed season, fishing effort, management, populations African Journal of Aquatic Science 2008, 33(1): 69–76

[Extract] In most areas in Malawi, temperatures are below 22°C except for the lakeshore region.Therefore, provision of low-cost technique to increase water temperatures should constitute an important means for Malawi to boost tilapia production including Tilapia rendalli. This study was conducted to determine if clear plastic sheeting would result in increased temperature and growth of T.rendalli.

Features and increments of otoliths in Engraulicypris sardella were observed. The sagitta was arrowhead shaped with an obvious core and rostra, the latter being fragile and easily destroyed by extracting and grinding processes. Increments around the core were readable but not in rostra. The lapillus was round fan-shaped with an obvious core. Increments in the lapillus were clearly deposited from the core to the margin. The asteriscus had an ambiguous core that led to difficulty in discerning the first increment and had fewer increments than the lapilli. Thus, the lapillus is the most appropriate for reading otolith increments.

Genetic diversity and relationships were assessed in 141 locally named banana cultivars growing in five districts of Malawi at 12 microsatellite loci. High allelic diversity (174 alleles) attributable to high frequency of duplicated alleles was observed. Primers discriminating power was high with mean polymorphism information content (PIC) of 0.74. Low mean genetic diversity contrary to actual allele count was detected by Nei’s gene diversity index (h, 0.12) and Shannon information index (I, 0.18). The low genetic diversity estimation could be due to loss of co-dominance by simple sequence repeats (SSR) loci in polyploids which leads to underestimation of allelic relationships in populations. The results also reveal that the genetic diversity of bananas from Chitipa, Karonga, Nkhata Bay, Thyolo, Mulanje, BRS local collection and BRS gene bank is not significantly different. Pooled northern region population (Chitipa, Karonga and Nkhata Bay) is as genetically diverse as pooled southern region population (Thyolo, Mulanje, Local collection and Gene bank). Cluster analysis showed that most cultivars were dissimilar probably due to multiplicity of mutations generated by high rate of cultivar multiplication by farmers. However, genetic relationships among some cultivars showed some possible synonyms. Keywords : Bananas and plantains cultivars, genetic diversity, microsatellite markers.

The first comprehensive study of abundance, richness and distribution of Mbuna in Lake Malawi was carried out in the 1980s. The present study examined changes of species richness and abundance of Mbuna with time. Most sites demarcated during the 1980s survey were explored in order to determine changes in abundance and composition of Mbuna over a period of more than 20 years. Chi-square analysis revealed significant difference (p ＜ 0.05) in abundance of Mbuna between 1983 and 2005 with the exception of Chinyankhwazi and Chinyamwezi where the difference was not significant (p ＞ 0.05). Cluster analysis showed changes in species composition between 1983 and 2005 in various sites. Generally, there were more species lost in a given area than new species observed in 2005. Decline in Mbuna species richness might have been caused by siltation, harvesting of Mbuna for food and ornamental fish trade while new species were mostly introduced through translocation from one part of the lake to another.