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Population genetic status of endangered whitespotted whipray Maculabatis gerrardi (Gray, 1851) in Tanzania
(Western Indian Occen Journal of Marine Science, 2024) Shabani, Maulidi; Malisa, Allen L.; Nehemia, Alex
The whitespotted whipray Maculabatis gerrardi is exploited in Tanzania for its meat, skin and Accepted:cartilage, and is classified as an endangered species by the IUCN. A mitochondrial COI gene April 12, 2024fragment from 105 M. gerrardi individuals obtained from four unprotected and one protected Published:marine area in Tanzania was used to determine the present genetic diversity, demographics, and July xx, 2024effective population size of whiprays. Lower levels of nucleotide and haplotype diversity and Copyright:mean mutational effective population size were apparent in unprotected than in protected areas. Owned by the journal.Analysis of molecular variance (AMOVA) identified a significant genetic difference between sub- The articles are open accesspopulations of M. gerrardi and hierarchical AMOVA identified separate genetic stocks, indicative articles distributed underof high levels of philopatry or individual sedentarity in M. gerrardi. The importance of marine the terms and conditions of the Creative Commons Attribution (CC BY 4.0) licence. protected areas to conserve genetic diversity of whiprays is highlighted.
Genetic diversity and structure of opsaridium microlepis along lake Nyasa, Tanzania
(Tanzania Journal of Agricultural Sciences, 2023) Nehemia, A.; Mwakalesi, A. J.
Opsaridium microlepis is a fish species that serves as a source of revenue and protein to most people living near Lake Nyasa. However, the population of this species has witnessed a worrisome decline, leading the International Union for Conservation of Nature (IUCN) to classify it as a threatened fish species. The current work used partial mitochondrial cytochrome oxidase subunit I (COI) sequences to investigate the genetic diversity, effective population size, and structure of O. microlepis along the Lake Nyasa areas of Tanzania. The findings indicated that Kafyofyo had the highest nucleotide diversity (π = 0.20%) and haplotype diversity (h = 0.78), while Katumba had the lowest nucleotide diversity (π = 0.08%). The lowest haplotype diversity (h = 0.50) was recorded at Katumba and Mbambabay. The molecular analysis indicated significant differences across the subpopulations investigated (Overall PhiST (ΦST) = 0.093, P < 0.05). The mean Sum of Square deviation (SSD), Harpending's raggedness index (HRI), Tajima's D (D), and Fu's Fs (Fs) were 0.014, 0.157, 0.108, and -0.88680 respectively and neither the mismatch distribution nor the neutrality test findings were significantly different from zero. The mismatch distribution supports the idea of sudden population expansion. Consequently, the effective population size estimates are large for sampling sites with higher genetic diversity. Thus, the current study's findings can serve as a foundation for long-term strategic plans to conserve and manage populations of O. microlepis in areas with low genetic diversity and effective population size.
The current population genetic status of oreochromis niloticus (linnaeus, 1758) along the malagarasi river, Tanzania
(Elsevier, 2024) Nehemia, Alex; Umbayda, Tlehema
In East African countries, the O. niloticus species is the second most important fish species in terms of economic significance. However, localized overfishing, habitat degradation, and hybridization have resulted in pop ulations’ decline that poses a threat to this species in this area. This study assessed the genetic diversity, pop ulation structure, demographic history, and effective population size of this species along the Malagarasi River. Comparisons were made between the population genetic structure and demographic history of populations of this species from Malagarasi River and other sites in the East Africa (EA) region. The study used COI gene se quences isolated from O. niloticus species collected along the Malagarasi River and COI gene sequences of this species from other sites in the EA region. The populations of O. niloticus from the Moyowosi had the highest haplotype diversity (0.80 ± 0.06) and nucleotide diversity (0.72 ± 0.41 %). At Ilagala, the lowest haplotype diversity (0.44 ± 0.13) and nucleotide diversity (0.16 ± 0.13 %) were found. Fixation index (Fst value) analysis resulted into significant genetic difference among the populations along Malagarasi River (Fst = 0.08419, P < 0.01). The Fst values and minimum spanning haplotype network revealed genetic break between population of O. niloticus from the Malagarasi River and other sites of the EA region. In order to ensure the sustainable exploitation of O. niloticus and other threatened fish species along the Malagarasi River, these findings urge for strengthening the implementation of fisheries laws, particularly in areas where samples exhibit low genetic diversity.
Population expansion but limited gene flow in kuhl's blue-spotted maskray along the Tanzanian coast
(2024) Nehemia, Alex; Shabani, Maulidi; Malisa, Allen Lewis
The blue-spotted maskray Neotrygon kuhlii (Müller & Henle, 1841) is a member of the Dasyatidae family of stingrays which grows slowly. Members of this group mature late and have a low fecundity rate. The ICUN Red List of Threatened Species lists N. kuhlii species as data deficient (DD) because information on its ecology and life history is not readily available. The purpose of this study was to determine the genetic diversity, demographic history and population structure of N. kuhlii, all of which are critical information for efforts aimed at conserving the species. The investigation was carried out along Tanzania's coastline using 595 base pairs of partial mitochondrial cytochrome oxidase subunit I (COI) sequence. The haplotype diversity ranged between 0.37 and 0.70 and nucleotide diversity between 0.11% and 0.50%. The findings show that samples from Unguja had higher mean molecular diversity indices than those from other sampling sites. Nonetheless, samples from Mafia and Unguja were found to have the largest effective population size. Genetic variations were found between the subpopulations under study, suggesting limited genetic connectivity among the studied subpopulations. The COI sequences of N. kuhlii from most subpopulations studied showed signs of past population expansion, which are typical for most Western Indian Ocean (WIO) fauna. The findings highlight the need for enhanced management and conservation strategies for N. kuhlii and other coastal stingray species in Tanzania, particularly in areas where sampling sites showed low levels of genetic diversity and effective population size.
Mitochondrial genetic diversity and demographic history of critically endangered oreochromis karongae (trewavas, 1941) along lake nyasa, Tanzania
(John Wiley & Sons, 2024) Nehemia, Alex; Mwakalesi, Alinanuswe J.
Fish provide food and income opportunities for millions of people in Lake Nyasa, also known as Lake Malawi in Malawi and Lake Niassa in Mozambique. Oreochromis karongae (Trewavas, 1941), which is native to Lake Nyasa, Lake Malombe and the Shire River, is at the verge of extinction and has been listed as critically endangered species by the International Union for Conservation of Nature (IUCN), primarily due to overfishing. Using 632 bp of partial mitochondrial cytochrome oxidase subu- nit I (COI) sequences from 115 samples, this work aims to assess the population genetic status and demographic history of this species to better manage and advance its conservation. The analysis of molecular variance (AMOVA) revealed a low and non- significant genetic differentiation index across the populations under study (ΦST = 0.003, p = 0.278), indicating a lack of popu- lation genetic structure. Phylogenetic analysis, grouped together all COI haplotypes of O. karongae from the six sampled sites. Nonetheless, the results showed signs of population expansion from a historic bottleneck, consistent with most data from the Western Indian Ocean Fauna. The findings from this study could be used to improve management and conservation strategies for critically endangered O. karongae in Lake Nyasa.
Anthropogenic activities along the lake nyasa catchments alter the habitat and genetic diversity of a lake salmon, opsaridium microlepis
(Heliyon, 2024) Nehemia, Alex; Mwakalesi, Alinanuswe J.
The Lake Salmon, Opsaridium microlepis is an economically important fish along the Lake Nyasa. However, the species is under threat of extinction due to anthropogenic activities such as agri culture, mining, urbanization, and deforestation. Consequently, the fish species is currently regarded as a threatened species, and the International Union for Conservation of Nature (IUCN) has red-listed the species due to an apparent decline in abundance. The current study assesses the potential impact of human activities on the genetic diversity of O. microlepis using partial mito chondrial cytochrome oxidase subunit I (COI) sequences and microsatellite loci. The results indicate that genetic diversity is lower in the areas affected by human activities compared to relatively pristine areas. The results from this study may suggest that human activities taking place in the catchments are likely to contribute to the alteration of the genetic diversity of O. microlepis species. Thus, immediate measure is required to control anthropogenic activities in the areas to protect the species and other aquatic organisms from possible threats of extinction.
Genetic variation and lack of hybridization in five cichlid fish species in the Malagarasi River basin, Tanzania
(Elsevier, 2025) Nehemia, Alex
Among the most widely cultured groups of freshwater fish species are tilapiine cichlids. This has contributed to introduction of cichlid fish species in area where they were not native. Consequently, has contributed to negative ecological effects on local species and their habitats through competition, habitat alteration and loss of unique population genetic structures due to hybridization. This research study aimed to assess the genetic status of five cichlid fish species red listed by the International Union for Conservation of Nature (IUCN) as least concerned species. A mitochondrial Cytochrome Oxidase Subunit I (COI) gene fragment from 112 individuals collected from three sampling sites were used to determine the present genetic diversity of the cichlid species inhabit the Malagarasi River system which discharge water into Lake Tanganyika. The highest nucleotide diversity (0.02 ± 0.01) and haplotype diversity (0.94 ± 0.04) were recorded from Haplochromis pharyngalis. The lowest levels of nucleotide and haplotype diversity were recorded from Oreochromis leucostictus. The Analysis of Molecular Variance (AMOVA) resulted into statistically significant genetic differences (Φst: 0.96, P < 0.001) among the cichlid species studied. The minimum spanning haplotype network and maximum-likelihood phylogenetic an alyses support the AMOVA findings as no species is sharing any haplotype with other species. The values of neutrality tests suggested that the studied cichlid fish species are stable and not expanding. These findings highlight the necessity of conservation interventions in the area especially for the species which displayed low nucleotide and haplotype diversity.
Commonly caught fish species as potential indicators of pollution along lake nyasa (lake Malawi), Tanzania
(Royal Society of Chemistry, 2024) Mwakalesia, Alinanuswe J.; Nehemia, Alex N.
The chapter presented the potential use of frequently caught fish species from Lake Nyasa as bioindicators of pollution that is likely to be a result of human activities. The effects of pollution can be magnified if proper and periodic assessments of risks associated with the pollution are not properly done. The sampling and analyses of pollutants accumulated in the sediments is always difficult. However, pollution induces stresses that can be detected through the molecular analysis of the fish. Thus, parameters such as genetic diversity, haplotype diversity (h), nucleotide diversity (π), observed heterozy- gosity (Ho) and unbiased expected heterozygosity can be used as potential indicators of the effects of pollution in aquatic systems. It is also possible for a pollutant contained in the aquatic systems to accu- mulate in the body tissues of the fish. The concentration of persistent and non-biodegradable heavy metals in fish increases with eating behaviour, age or rate of exposure. Thus, the concentration of heavy metals may vary from one fish species to another depending on the factors. The heavy metals accu- mulated in the body of the fish can be used to estimate potential risks that can be caused by pollution to human health. The toxicity of a pollutant highly depends on the chemical form in which it is present in the aqueous environment. For example, organic mercury is more toxic compared to inorganic mercury due to its ability to penetrate through various blood barriers and cause neurological damage. The chem- ical characteristics of a toxicant vary from one another. Thus, to estimate potential risks associated with a certain pollutant, the analysis of a specific chemical species is required. The use of fish as a potential bioindicator can be significantly more relevant, if these aspects are borne in mind during the chemical speciation analysis.
DNA barcoding validates new sightings of tridacna elongatissima in Tanzania and Mozambique (Western Indian Ocean)
(Springer, 2022) Velkeneers, Xander; Dissanayake, P. A. K. N.; Huyghe, Filip; Nehemia, Alex; Ratsimbazafy, Hajaniaina Andrianavalonarivo; Kochzius, Marc
There are currently 12 recognised extant species of giant clams (Cardiidae: Tridacninae) inhabiting the tropical waters of the Indo-Pacific. Six species have been newly described or rediscovered since 1982, such as the recently resurrected species Tridacna elongatissima in the Western Indian Ocean. In order to investigate the distri- bution range of this species, 24 specimens have been col- lected and identified by DNA barcoding. This study provides the first record for T. elongatissima in Tanzania and expands both the northern (Zanzibar, Tanzania) and southern (Ponta de Ouro, Mozambique) ranges of this species.
DNA barcoding reveals endangered and protected elasmobranchs in Tanzanian fish markets
(Western Indian Ocean Journal of Marine Science, 2023) Rumisha, Cyrus; Simwanza, Rehema J.; Nehemia, Alex; Mdegela, Robinson H.; Kochzius, Marc
Western Indian Ocean countries have banned elasmobranch finning and enacted legislation to of Marine Science 22(1): 57-65protect endangered elasmobranchs, however finned and morphologically deformed specimens [doi: 10.4314/wiojms.v22i1.6]are still landed and traded on Tanzanian fish markets. Such specimens are difficult to identify Received:morphologically, and it is possible that protected elasmobranchs are among these. This study September 19, 2022used DNA barcoding to uncover protected elasmobranchs in 102 specimens traded on Tan- Accepted:zanian fish markets. The sampled specimens revealed 23 elasmobranch species, 12 of which April 04, 2023(52.1 %) were classified as endangered (EN) or critically endangered (CR) on the IUCN Red List. Published:Three of the identified species (great hammerhead Sphyrna mokarran, oceanic whitetip shark June 16, 2023Carcharhinus longimanus, and pelagic thresher Alopias pelagicus) are protected by Tanzanian laws. Copyright:Hence, it is advised that steps be taken to strengthen law enforcement at landing sites and fish Owned by the journal.markets in the country. Furthermore, the Third Schedule of Fisheries (Amendment) Regula- The articles are open accesstions of 2009 should be updated to include 11 EN and CR elasmobranchs that are not on the list. articles distributed underAdditionally, national and regional elasmobranch conservation plans should be developed to the terms and conditions of the Creative Commons Attribution (CC BY 4.0) licence. prevent the exploitation of endangered elasmobranchs.
Contamination and health risk assessment of heavy metals in selected highly edible fish species from lake nyasa, Tanzania
(The Tunisian Chemical Society and Springer Nature Switzerland, 2023) Mwambene, Bupoki; Mwakalesi, Alinanuswe Joel; Nehemia, Alex Nahnson
Heavy metal contamination emanating from increased industrial and anthropogenic activities poses considerable environmen- tal risks to water resources, aquatic biodiversity, and human health. These metals are major sources of various unfavorable environmental changes and human health hazards. This research investigated the potential contamination level and health risk assessment of heavy metals (Fe, Zn, Ni, Cu and Cr) in five highly edible fishes (O. microlepis, C. gariepinus, O.niloticus, R. moorii,B. meridionalis) from Lake Nyasa. The results indicated that gills contained higher amounts of heavy metals compared to muscles. The levels of Fe and Zn were higher in the gills of C. gariepinus and O.niloticus than O. microlepis, R. moorii, and B. meridionalis. Similarly, amounts of Cu and Cr were higher in the gills of C. gariepinus and O. microlepis. The general trend of heavy metal concentrations accumulated in selected fish species was Fe > Zn > Ni > Cu > Cr. The amounts of heavy metals found in the fish samples were within acceptable limits set by FAO and WHO. Furthermore, the risk assessments indicated that the current exposure levels are unlikely to cause serious health risks. However, the progressive monitoring of levels of heavy metals in various aquatic organisms from Lake Nyasa is important for the continued protection of human health against hazardous health effects
Population Genetic Structure and Demographic History of Opsaridium microcephulum along Lake Nyasa
(University of Dar es Salaam, 2023) Nehemia, Alex; Mwakalesi, Alinanuswe J.
The Sanjika, Opsaridium microcephalum is among the fish species that serve as a major source of proteins and income to people along Lake Nyasa. However, the information on its genetic diversity and structure particularly in the Tanzania part of the Lake is limited. Therefore, the assessment of the genetic diversity and structure of O.microcephalum along the Lake Nyasa part of Tanzania was conducted in the current study using a fragment of the mitochondrial COI gene from 92 individuals of O. microcephalum. The findings showed that an average haplotype diversity and average nucleotide diversity were 0.8065 ± 0.0314 and 0.002380 ± 0.001640, respectively. The molecular Variance (AMOVA) indicated significant genetic variations among the subpopulations studied (Overall Φst = 0.31560, p < 0.001). The lowest haplotype diversity was recorded at Manda and the highest haplotype diversity was recorded at Buloma. The lowest nucleotide diversity was recorded at Manda and the highest was recorded at Lupingu. The differences in genetic diversity can be a possible indicator of different localised evolutionary forces that require attention to conservationists for the sustainable management of O. microcephalum.
Genetic diversity, population genetic structure and demographic history of the Ribbontail stingray Taeniura lymma (Fabricius, 1775) (elasmobranchii: myliobatiformes: dasyatidae) along the Tanzanian coastline
(Taylor & Francis, 2024) Nehemia, Alex
The Ribbontail stingray Taeniura lymma is an economically important fish and attractive species for the aquarium trade industry. Overfishing, habitat degradation, and pollution, however, pose a threat to this species. This study used partial mitochondrial cytochrome oxidase subunit I (COI) sequences (603 base pairs long) from 96 samples of T. lymma collected at five fish-landing sites (Deep Sea-Tanga, Malindi-Unguja, Kaole-Bagamoyo, Kivukoni-Dar es Salaam, and Bandarini-Mtwara) located along the coast of Tanzania to determine the species’ genetic diversity, population genetic structure, and demographic history. The findings revealed an average nucleotide diversity of 0.24 ± 0.16% and a haplotype diversity of 0.75 ± 0.04. Nucleotide and haplotype diversities were relatively low at Kaole-Bagamoyo compared to the other studied localities. An Analysis of Molecular Variance (AMOVA) indicated limited but statistically significant genetic differences among populations (Overall FST = 0.09, p < 0.01). Pairwise AMOVA revealed genetic difference between the Deep Sea-Tanga population and all other populations studied with exception of Malindi-Unguja. Analyses of mismatch distribution, demographic history, and a haplotype network support a scenario of historical population expansion in the studied species. Immediate effort is required to protect population exhibiting low genetic diversity in this commercially important ray.
Health and social support services to HIV/AIDS infected individuals in Tanzania: Employees and Employers perceptions
(BMC Public Health, 2014) Kassile, Telemu; Anicetus, Honest; Kukula, Raphael; Mmbando, Bruno P
Background: HIV is a major public health problem in the world, especially in sub-Saharan Africa. It often leads to loss of productive labour and disruption of existing social support system which results in deterioration of population health. This poses a great challenge to infected people in meeting their essential goods and services. This paper examines health and social support services provided by employers to HIV/AIDS infected employees in Tanzania. Methods: This was a cross-sectional study, which employed qualitative and quantitative methods in data collection and analysis. Structured questionnaires and in-depth interviews were used to assess the health and social support services provision at employers and employees perspectives. The study participants were employees and employers from public and private organizations. Results: A total of 181 employees and 23 employers from 23 workplaces aged between 18–68 years were involved. The results show that 23.8% (i.e., 20.4% males and 27.3% females) of the employees had at least one member of the family or close relatives living with HIV at the time of the study. Fifty six percent of the infected employees reported to have been receiving health or social support from their employers. Employees’ responses were consistent with those reported by their employers. A total of 12(52.2%) and 11(47.8%) employers reported to have been providing health and social supports respectively. Female employees (58.3%) from the private sector (60.0%) were more likely to receive supports than male employees (52.6%) and than those from the public sector (46.2%). The most common health and social support received by the employees were treatment, and nutritional support and reduction of workload, respectively. Conclusions: HIV/AIDS infected employees named treatment and nutritional support, and soft loans and reduced workload respectively, as the most important health and social supports they needed from their employers. This study provides baseline information for further studies on provision of health and social support services by employers to HIV/AIDS infected employees in the context of a developing economy like Tanzania. Keywords: Family member, Treatment and nutritional support, Workload, Workplaces
Improved household nutrition through home-grown produce and consumption of nutritious and healthy products
(Sustainable Agricultural Intensification, 2022) Anitha, Seetha; Sefa, Victor Afari; Kalumikiza, Zione; Mhango, Khumbo; Mosha, Inviolate; Muzanila, Yasinta; Mwangwela, Agnes; Ochieng, Justus; Okori, Patrick; Tsusaka, Takuji W
Undernutrition causes stunting, underweight, and wasting, and these are major health issues throughout Africa, adversely affecting the phys- ical and mental growth and development of chil- dren. High rates of stunting are seen throughout East and Southern Africa (ESA), with rates of 34% and 26% in the Africa RISING project coun- tries of Malawi and Tanzania (MoHCDGEC et al., 2016; NSO and ICF, 2017). Micronutrient defi- ciencies (e.g., iron, zinc, and calcium), described as hidden hunger, remain rife in both countries, especially among women of reproductive age, in- fants, and young children. These deficiencies have significant consequences for maternal and child health, mortality, the global burden of dis- ease, and economic development. In Malawi, for example, it is estimated that child undernutrition resulted in economic losses equivalent to 10.3% of gross domestic product in 2012. To this end, the Government of Malawi has reviewed its nutrition policy to redirect the national focus on nutrition programming and align its goals with the Malawi Growth and Development Strategy III (Government of Malawi, 2018). Tanzania has also shown commitment to addressing undernu- trition by articulation of the National Nutrition Strategy (United Republic of Tanzania, 2016). Both national policies recognize the need for multi-sectoral approaches to address malnutri- tion by promoting dietary diversity. A dietary approach needs to target the key growth window of opportunity in children, par- ticularly between 6 and 23 months of age, when growth is rapid and at risk of faltering when nu- trition is lacking (Ferguson et al., 2015). This co- incides with the weaning period and is an ideal time to introduce affordable, acceptable, and nutrient-rich foods. Dietary diversity can be improved through both nutrition-specific and nutrition-sensitive agricultural interventions. Nutrition-specific interventions address the immediate causes of undernutrition, i.e., inadequate diets and ill- nesses caused by nutrient deficiency. Nutrition- sensitive interventions incorporate nutrition objectives in wider disciplines; for example, ad- vice on producing crops and varieties that are rich in nutrients, and improved post-harvest processing and storage to minimize loss and im- prove quality and nutritional composition.
Occurrence of aflatoxins and its management in diverse cropping systems of central Tanzania
(Springer, 2017) Seetha, Anitha; Munthali, Wills; Msere, Harry W; Swai, Elirehema; Muzanila, Yasinta; Sichone, Ethel; Tsusaka, Takuji W; Rathore, Abhishek; Okori, Patrick
The staple crops, maize, sorghum, bambara nut, groundnut, and sunflower common in semi-arid agro-pastoral farming systems of central Tanzania are prone to aflatoxin contamination. Consumption of such crop produce, contami- nated with high levels of aflatoxin B 1 (AFB 1 ), affects growth and health. In this paper, aflatoxin contamination in freshly harvested and stored crop produce from central Tanzania was examined, including the efficacy of aflatoxin mitigation tech- nologies on grain/kernal quality. A total of 312 farmers were recruited, trained on aflatoxin mitigation technologies, and allowed to deploy the technologies for 2 years. After 2 years, 188 of the 312 farmers were tracked to determine whether they had adopted and complied with the mitigation practices. Aflatoxigenic Aspergillus flavus and aflatoxin B1 contamina- tion in freshly harvested and stored grains/kernels were assessed. A. flavus frequency and aflatoxin production by fungi were assayed by examining culture characteristics and thin-layer chromatography respectively. AFB 1 was assayed by enzyme-linked immunosorbent assay. The average aflatoxin contamination in freshly harvested samples was 18.8 μg/kg, which is above the acceptable standard of 10 μg/kg. Contamination increased during storage to an average of 57.2 μg/kg, indicating a high exposure risk. Grains and oil- seeds from maize, sorghum, and sunflower produced in aboveground reproductive structures had relatively low afla- toxin contamination compared to those produced in geocarpic structures of groundnut and bambara nut. Farmers who adopted recommended post-harvest management practices had considerably lower aflatoxin contamination in their stored kernels/grains. Furthermore, the effects of these factors were quantified by multivariate statistical analyses. Training and behavioral changes by farmers in their post-harvest practice minimize aflatoxin contamination and improve food safety. Moreover, if non-trained farmers receive mitigation training, aflatoxin concentration is predicted to decrease by 28.9 μg/kg on average.
Ecological impact of salt farming in mangroves on the habitat and food sources of austruca occidentalis and littoraria subvittata
(Elservier, 2019) Nehemia, Alex; Chen, Margaret; Kochzius, Marc; Dehairs, Frank; Brion, Natacha
The impact of salt farming on the habitats and food sources of Austruca occidentalis and Littoraria subvittata was studied in mangroves along the coast of Tanzania using stable isotopes ( 13 C and 15 N) and sediment particle size analysis. The 13 C and 15 N stable isotope composition in mangrove leaves, sediments and invertebrate tissues, were used to evaluate whether there are differences in feeding ecology of the crab Austruca occidentalis and the snail Littoraria subvittata collected from natural mangroves and mangroves around the salt ponds. Organic C, total N content and particle size distribution in sediments were used to assess if there are differences in habitat characteristics of mangroves around the salt ponds. Mangrove leaves and sediments were found to be 13 C en- riched around salt ponds compared to those from natural mangroves. Likewise the macroinvertebrates collected from mangroves around salt ponds were found be enriched in 13 C relative to undisturbed mangroves. In addition, mangrove sediments around salt ponds were poorer in organic carbon and nitrogen and had more sand content compared to sediments from natural mangroves. These results indicate that salt pond activities have contributed to the modification of the habitats of macroinvertebrates by causing δ 13 C stable isotopes enrichment and al- teration of sediment characteristics in the ecosystem.
Drivers of millet consumption among school aged children in central Tanzania
(Frontiers, 2021) Chande, Monica; Muhimbula, Happiness; Mremi, Ruth; Muzanila, Yasinta C; Kumwenda, Nelson C; Msuya, John; Msere, Harry; Bekunda, Mateete; Okori, Patrick; Gichohi-Wainaina, Wanjiku N
Background: Iron and zinc deficiency are common public health problems in low-income countries largely due to poor consumption of iron and zinc rich foods. It has previously been observed that 57% of school aged children (SAC) in Tanzania suffer from anemia. In addition, estimates indicate that over 25% of the population have inadequate zinc intake. Pearl millet is an example of a nutrient dense, resilient cereal crop, that can be promoted to diversify diets and combat iron and zinc deficiency. This study overall aim was to increase pearl millet consumption among school aged (5 – 12 years) children. As part of the study, we investigated, the drivers of food choice relating to pearl millet consumption. Methods: The study was a cross-sectional study of randomly selected households in Kongwa district, Dodoma region of Tanzania. In total, 128 women of reproductive age (20 – 49 years) were randomly selected for the study. A study questionnaire consisting of 66 items, was developed and validated. The constructs in the questionnaire were categorized in two groups: internal and external factors. Respondents were asked to indicate their level of agreement or disagreement with statements read to them by interviewers. The scores on intention and behavior constructs were based on the number of times caregivers intended to, or had fed their school going children with pearl millet in the referent month. Intention was considered high if it was higher than the median intention score of the group, and low if it was equal to or lower than the median scores. Correlations and multiple linear regressions were performed to measure association between constructs and to identify predictive constructs. The Mann-Whitney U test was used for score comparison. Results: There was a significant difference between intention and behavior among those who did not consume pearl millet (P = 0.003), and those who consumed pearl millet two or more times a week, in the same month (P = 0.01). Knowledge was significantly correlated with behavior identity (ρ = 0.58, P = 0.001), while health behavior identity was significantly correlated with intention (ρ = 0.31, P = 0.001). Intention of caregivers was significantly and positively correlated (ρ = 0.44, P = 0.001) with and predicted consumption of pearl millet (ρ = 0.87, P = 0.067).
Reducing child undernutrition through dietary diversification, reduced aflatoxin exposure, and improved hygiene practices: the immediate impacts in central Tanzania
(Routledge Taylor & Francis Group, LLC., 2019) Anitha, Seetha; Muzanila, Yasinta; Tsusaka, Takuji W; Kachulu, Lizzie; Kumwenda, Nelson; Musoke, Mike; Swai, Elirehema; Shija, Jackson; Siambi, Moses; Monyo, Emmanuel S; Bekunda, Mateete; Okori, Patrick
The study aimed to quantify the immediate effects of dietary diversification, food safety, and hygiene interventions on child undernutrition in four rural villages in Kongwa district of cen- tral Tanzania. One hundred mothers with their children of less than 24 months old were recruited for this study. The differ- ence-in-difference (DID) method was used to assess the effects of intensive intervention through a learning-by-doing process on the topic of aflatoxin free diversified food utilization and improved hygiene practices. Periodic anthropometric measure- ments were conducted on the 0th, 7th, 14th, and 21st days, and DID estimator showed the significant and positive average marginal effects of the intervention on Z-Scores being 0.459, 0.252, and 0.493 for wasting, stunting, and underweight, respectively. Notably, at the end of the study, the mean aflatoxin M 1 level in urine samples decreased by 64% in the intervention group, while it decreased by 11% in the control group. The study provides quantitative evidence on intensive 21-day training for mothers incorporating integrated technol- ogies yielded positive impacts on their children’s nutritional outcomes.
Genetic erosion in the snail littoraria subvittata (reid, 1986) due to mangrove deforestation
(Journal of molluscan studies, 2016) Nehemia, Alex; Huyghe, Filip; Kochzius, Marc
In tropical coastal ecosystems mangrove forests are important as feeding, spawning, breeding and nursery grounds for many marine species. High human population pressure in coastal areas has led to the loss and deterioration of mangrove habitats. Solar salt production can affect these habitats along the East African coast. Littorinid snails live on mangrove trees, forming an important component of the mangrove ecosys- tem and have been used as bioindicators of environmental health and community stress. Littoraria subvittata is the most abundant littorinid species in mangroves along the East African coast. Partial mitochondrial cytochrome oxidase subunit 1 (COI) gene sequences of 298 individuals were used to assess the impact of mangrove deforestation at salt ponds on the genetic diversity and structuring of L. subvittata populations, as well as to infer the demographic history of the species. Nucleotide and haplotype diversities were found to be lower in samples from mangroves at salt ponds than in samples from natural mangroves. The mean nucleotide diversity was 0.049 ± 0.036% and 0.115 ± 0.068% in mangroves at salt ponds and natural mangroves, respectively. The mean haplotype diversity was 0.23 ± 0.14 and 0.50 ± 0.14 in mangroves at salt ponds and natural mangroves, respectively. Analysis of molecular variance (AMOVA) detected a sig- nificant population structure (Ф st = 0.049; P < 0.0001) for the combined populations. Hierarchical AMOVA detected a significant population genetic structure only between populations from mangroves at salt ponds and natural mangroves (Φ ct = 0.022; P < 0.05), but not between any other groupings. Populations from natural mangrove sites showed a significant genetic structure (Ф st = 0.054, P < 0.0001), while populations from sites at salt ponds could not be differentiated (Ф st = −0.0026, P = 0.64). Reduced effective population size was observed in most samples from mangrove sites at salt ponds compared with natural mangrove. The direction of migrants was mostly from salt ponds to natural mangroves. These results show that salt ponds have a negative impact on the genetic diversity of L. subvittata populations and modify the population’s genetic structure.

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