East Coast Of Madagascar Research Articles

A new miniaturized species of leaf chameleon, genus Brookesia, from a littoral forest fragment in eastern Madagascar.

The number of species of miniaturized chameleons of the genus Brookesia, subgenus Evoluticauda, known to science has witnessed a dramatic increase over the past 15 years, due to the discovery of multiple microendemic species of very strong genetic divergence. So far, no described Evoluticauda species are known from the littoral forest of Madagascar's east coast, one of the most threatened habitat types of the island. Here, we report on the discovery of a new species of Evoluticauda occurring in the littoral forest at Ankanin'ny Nofy, a touristic site at about sea level and close to Vohibola forest where probably the same species occurs. The new species, Brookesia nofy sp. nov., is sister to B. ramanantsoai which occurs in mid-altitude and highland forests (800-1300 m a.s.l.) at a similar latitude of eastern Madagascar, but differs from this species by an enormous genetic divergence in both mitochondrial and nuclear genes (8.1-9.4% uncorrected pairwise distance in the 16S rRNA gene, 1.8-2.5% in c-mos), a relatively shorter tail, a different arrangement of cephalic ridges, and probably smaller body size and relatively larger head. The discovery of B. nofy sp. nov. emphasizes the importance of conserving Madagascar's last remaining fragments of littoral forest.

A New Insight into the Genesis of Graphite Deposits in Madagascar Using U–Pb Zircon Dating and Electron Microprobe Analysis

Madagascar is globally recognized as an important producer of high-quality flaky graphite. However, current research on graphite deposits in Madagascar remains insufficient. Previous studies have linked the genesis of Madagascan graphite deposits to the metamorphism of sedimentary organic matter. Here, we provide a case study of graphite deposits in Madagascar, combining new data from the Ambahita graphite deposit (AMG) in southern Madagascar with data from the Antanisoa graphite deposit (ANG) in central Madagascar and the Vohitasara graphite deposit (VOG) on the east coast of Madagascar. We note that the mineral assemblages of graphite-bearing rocks in the AMG, ANG, and VOG are not typical of metamorphic mineral assemblages but rather the results of filling and metasomatism by mantle-derived fluids that occurred after peak metamorphism. Electron microprobe analysis indicates that the graphite of the AMG, VOG, and ANG is usually associated with phlogopite or Mg-biotite; the phlogopite shares a common genesis with other widespread phlogopite deposits across Madagascar. We reveal that the distribution of graphite deposits in Madagascar is primarily controlled by ductile shear zones between blocks. Ductile shear zones that extend deep into the mantle can provide an ideal migration channel and architecture for the emplacement of mantle-derived fluids. The graphite mineralization formed no earlier than the peak metamorphism (490 Ma) and no later than the intrusion of pegmatite veins (389 ± 5 Ma). The distribution of graphite deposits, graphite orebody morphologies, mineral associations, and geochemical data suggest that the genesis of graphite deposits in Madagascar is linked to mantle-derived fluid filling rather than the metamorphism of sediments, as previously suggested. These findings have important implications for similar deposits in Madagascar and potentially globally.

Decreasing diarrhea cases through on-site sodium hypochlorite production in Madagascar

Abstract Schools from Sainte-Marie Island, off the east coast of Madagascar, participated in water, sanitation, and hygiene (WASH) programs. We report an association between the program, the sustainable access to water treatment (WT) in 20 schools, and the impact on diarrhea incidence in the region. We performed a quasi-experimental longitudinal study on the program's sustainability by accessing the continuation of point-of-use (POU) water chlorination, safe water storage (SWS), and handwashing practices on the diarrhea cases of children. Patient files from 10 health centers near the schools were consulted. Sodium hypochlorite was locally produced by the students for WT and the program's sustainability was accessed between 2016 and 2021. After the intervention, 40% of water sources were entirely replaced and 60% received improvements. A student's water club, guided by teachers, was responsible for all activities related to WT. The health centers around the schools participating in the program saw diarrhea cases drop by 58% between 2018 and 2021. There appears to be an association between a decrease in diarrhea cases and the program's implementation. The strategy used can be replicated. Nevertheless, the program's success is multifactorial, depending on community engagement, adapted technology, funding, and governmental support to ensure sustainability.

From shifting rice cultivation (tavy) to agroforestry systems: a century of changing land use on the East Coast of Madagascar

From shifting rice cultivation (tavy) to agroforestry systems: a century of changing land use on the East Coast of Madagascar

Evaluation of the vulnerability of groundwater to nitrogen pollution in the commune of Mananara Avaratra by the SINTACS method

The urban commune of Mananara Avaratra, located on the east coast of Madagascar in the Analanjirofo region, is characterized by alluvial soils, mainly sandy and ferruginous, and a tropical climate. Groundwater is considered as the main source of drinking water for the local population although the presence of pollution by nitrogen compounds has been a serious environmental problem for more than a decade This study aimed at developing a groundwater vulnerability model for nitrate and ammonium as a protective measure. Based on the intrinsic vulnerability determined by the SINTACS model, the influence of anthropogenic parameters related to nitrogen sources and groundwater use on contamination was verified using GIS. Chemical analyses showed high concentrations of nitrate (136.987 mg.l-1) and ammonium (1.120 mg.l-1) in the samples. The high nitrate and ammonium concentrations were found in the northern subwatershed, probably due to the area impacted by urbanization by urbanization, where the groundwater vulnerability index is high (high index is 197 - 210 and for the very high ones 215 - 223). On the other hand, the concentrations in the southern subwatershed are lower, and the index is moderate (137 - 178). In order to prevent the contamination of groundwater by nitrogen, it is necessary to develop management policies on surface land use and groundwater, as well as to continuously monitor the latter.

Coming from elsewhere: the preponderance of introduced plant species in agroforestry systems on the east coast of Madagascar

Coming from elsewhere: the preponderance of introduced plant species in agroforestry systems on the east coast of Madagascar

Clinicoepidemiology of Skin Diseases in Children Seen at the University Hospital Center Morafeno, Toamasina, Madagascar.

Introduction The child's skin diseases are common and very diverse. Many studies concerning pediatric dermatoses have been carried out in Africa and the rest of the world. Few epidemioclinical data reflect these skin diseases in children, especially in the east coast of Madagascar. We aim to describe the pattern skin diseases among children seen at the University Hospital Center Morafeno, Toamasina, Madagascar. Patients and Methods. A retrospective study over a 3-year period from January 2017 to December 2019 was conducted in children seen in the Dermatology Department of University Hospital Center Morafeno, Toamasina, with skin diseases. Results During the study period, 347 children out of the 1584 new patients were retained with a sex ratio of 0.86. The mean age was 6.4 years old. The main diseases identified were skin infectious diseases (43, 23%), allergic dermatoses (24.21%), and autonomous dermatosis (15.56%). Conclusion Our study revealed the importance of infectious and allergic dermatoses in Toamasina. It is necessary to carry out simple preventive actions such as hygiene.

The main skin diseases seen in Toamasina (Madagascar)

Introduction. Dermatoses become a major public health problem in tropical countries. Few epidemiological data reflect these diseases, especially on the east coast of Madagascar. The aim of our study was therefore to describe the epidemiological, clinical aspect of skin diseases seen at the University Hospital Center (CHU) of Morafeno Toamasina. Patients and methods. We conducted a retrospective study during 2 years in patients seen in the department of Dermatology at University Hospital Morafeno Toamasina with skin diseases. Results. During the study period, 1085 patients were included with a sex-ratio of 0.73. The mean age was 30.9 years (range 4 days to 89 years). In order of frequency, infectious dermatoses ranked first with 39.17% of cases dominated by fungal infections, followed by autonomous dermatoses (23.96%) and allergic dermatoses (20.09%). The other groups of dermatological pathologies in small proportionwere tumor dermatoses (6.27%), congenital dermatoses (3.32%), autoimmune diseases (2.76%), toxidermia (1.38%) and overload dermatoses (0.37%). Conclusion. Skin conditions are still neglected in Toamasina. Knowledge of their epidemiological profile in the Atsinanana region contributes to improving the management of dermatological pathologies in Madagascar.

Une nouvelle espèce menacée de Euphorbia sect. Goniostema (Euphorbiaceae) du nord de Madagascar

Castillon, J.-P. & J.-B. Castillon (2018). A new threatened species of Euphorbia sect. Goniostema (Euphorbiaceae) from northern Madagascar. Candollea 73: 187–191. In French, English and French abstracts. DOI: http://dx.doi.org/10.15553/c2018v732a2Euphorbia longitubicinicyathium J.-P. Castillon & J.-B. Castillon (Euphorbiaceae), a new species from northeastern Madagascar is described and illustrated with field photographs. The new species belongs to Euphorbia sect. Goniostema Baill. ex Boiss. and is morphologically related to non thorny species of the east coast of Madagascar (e.g. Euphorbia geroldii Rauh, Euphorbia robivelonae Rauh or Euphorbia thuarsiana Baill.) but differs by its larger dimensions, its habit and its long trumpet shaped cyathia.

Clove based cropping systems on the east coast of Madagascar: how history leaves its mark on the landscape

Clove farming developed on the east coast of Madagascar a little over a century ago. The species is largely cultivated and farmed by communities of smallholders. This study aims to characterize clove based cropping systems. There are three types of coexisting clove systems: monoculture where clove is the sole crop with inter-rows covered by wild grasses, agricultural parklands where clove is associated with annual crops (rain fed rice, sugar cane, cassava) and finally complex agroforestry systems where clove is associated with other crops (vanilla), fruit trees (lychees, breadfruit, jackfruit) and pepper vines, as well as some forest trees. The study also shows that the majority of existing clove trees in the various cropping systems are over 50–60 years old. Our study aims to characterise the different clove based cropping systems with the intention of establishing a typology by measuring biometric criteria associated with clove trees, by determining the accompanying species and by characterising the horizontal and vertical structuration of plots. From these observations, we suggest some evolutionary hypotheses of clove systems in an attempt to resituate this typology in a historical dynamic implicating the agricultural history of the east coast of Madagascar and the evolution of the smallholders’ strategies.

Genetic diversity and connectivity in the East African giant mud crab Scylla serrata: Implications for fisheries management.

The giant mud crab Scylla serrata provides an important source of income and food to coastal communities in East Africa. However, increasing demand and exploitation due to the growing coastal population, export trade, and tourism industry are threatening the sustainability of the wild stock of this species. Because effective management requires a clear understanding of the connectivity among populations, this study was conducted to assess the genetic diversity and connectivity in the East African mangrove crab S. serrata. A section of 535 base pairs of the cytochrome oxidase subunit I (COI) gene and eight microsatellite loci were analysed from 230 tissue samples of giant mud crabs collected from Kenya, Tanzania, Mozambique, Madagascar, and South Africa. Microsatellite genetic diversity (He) ranged between 0.56 and 0.6. The COI sequences showed 57 different haplotypes associated with low nucleotide diversity (current nucleotide diversity = 0.29%). In addition, the current nucleotide diversity was lower than the historical nucleotide diversity, indicating overexploitation or historical bottlenecks in the recent history of the studied population. Considering that the coastal population is growing rapidly, East African countries should promote sustainable fishing practices and sustainable use of mangrove resources to protect mud crabs and other marine fauna from the increasing pressure of exploitation. While microsatellite loci did not show significant genetic differentiation (p > 0.05), COI sequences revealed significant genetic divergence between sites on the East coast of Madagascar (ECM) and sites on the West coast of Madagascar, mainland East Africa, as well as the Seychelles. Since East African countries agreed to achieve the Convention on Biological Diversity (CBD) target to protect over 10% of their marine areas by 2020, the observed pattern of connectivity and the measured genetic diversity can serve to provide useful information for designing networks of marine protected areas.

Almost One Century Later…Cantharellus avellaneusFinally Rediscovered!

Abstract The authors report on a brown chanterelle collected in the sandy soils of Madagascar's east coast. As this specimen agrees entirely with the protologue of C. avellaneus, it is here described and proposed as epitype for this apparently rare chanterelle that was first described in 1924 by Narcisse Patouillard. Its systematic placement as part of Cantharellus subg. Parvocantharellus sect. Congolenses is demonstrated using a multigene phylogeny and its complete ITS barcode sequence is provided.

Six, not two, species of Acisoma pintail dragonfly (Odonata: Libellulidae).

The dragonfly genus Acisoma is revised based on adult male morphology and COI sequence data. Six species are recognised, including the new species A. attenboroughi sp. nov. Diagnoses and a key to males of all species and illustrations of all relevant characters are provided. A. inflatum, A. variegatum and A. trifidum are confined to continental Africa, while A. panorpoides is restricted to Asia. A. ascalaphoides is known only from threatened littoral forest fragments on the east coast of Madagascar, while A. attenboroughi is widespread across the island. The new species honours Sir David Attenborough on his 90^th birthday.

Complementary description of the genus Manohyphella Allen, 1973 (Insecta: Ephemeroptera: Teloganodidae), with some comments on its ecology in the Andasibe area (East Coast, Madagascar)

Based on a large collection of material from the East Coast of Madagascar, we redescribe the endemic genus and species Manohyphella keiseri Allen, 1973. The male imago is described for the first time and details on the nymphal stage is provided, especially on the gill formula. The species M. animosa McCafferty & Benstead, 2002 and M. sphyxia McCafferty & Benstead, 2002 are considered as subjective junior synonyms of M. keiseri Allen, 1973. Notes on the life cycle of the species in the Andasibe area is presented, as well as data about the density of the populations. M. keiseri is an inhabitant of pristine running waters in rainforests and is therefore a good indicator for habitat quality.

A career-enriching experience.

Docked in Toamasina, on the east coast of Madagascar, the world's largest floating hospital ship is home to hundreds of nurses delivering health care to the world's fourth-largest island nation.

Interannual variability of South Equatorial Current bifurcation and western boundary currents along the Madagascar coast

AbstractThe South Equatorial Current (SEC) in the southern Indian Ocean bifurcates at the east coast of Madagascar into the Northeast and Southeast Madagascar Currents (NEMC and SEMC, respectively). In observational and reanalysis data, interannual variations of the NEMC and SEMC transports are strongly correlated with those of the SEC transport, rather than those of the SEC bifurcation latitude (SBL). Their dynamical mechanisms are then examined based on the Time‐Dependent Island Rule for the first time. It is shown that interannual anomalies of the SBL as well as the NEMC and SEMC transports are predominantly a response to the anomalous inflow from the ocean interior that is determined by the meridional interior transport. This, in turn, is a result of westward propagating Rossby waves induced by wind stress curl anomalies mainly in 60°E–90°E. The above mechanism is contrasted with that of the seasonal variation, where the local transport driven by wind stress around the island plays a role. Furthermore, the interannual variations of the SBL and the NEMC and SEMC transports are significantly correlated with the Niño 3.4 index with 5–15 months lag. It is suggested that diabatic heating anomalies associated with the El Niño/Southern Oscillation (ENSO) along with a local process in the southeastern Indian Ocean may generate wind stress curl anomalies over the southern Indian Ocean.

Complementarity of native and introduced tree species: Exploring timber supply on the east coast of Madagascar

In Madagascar, nature conservation and human livelihood security both appear as crucial imperatives. The degraded secondary forest remnant of Analalava, on the east coast, near Foulpointe, is a protected area since 2006. The long-term conservation of the site’s biodiversity can only be guaranteed by local support. Given that access to timber from native trees within the protected area is restricted, management of tree resources outside of the protected area represents a critical nexus between biodiversity conservation and human benefits linked to ecosystem services. We investigated and characterized the local farmer's use of available tree species, to provide a basis for satisfying the dual objectives of biodiversity conservation and sustainable and equitable rural development. Our results showed that local people are interested in various types of trees for timber, both native and introduced. Furthermore, they demonstrated detailed knowledge about silvicultural traits of a large number of tree species. Regarding the important complementarity of properties and uses recognized for native and introduced species we conclude that free distribution of nursery seedlings of fast-growing introduced tree species should not be the only alternative to logging within the protected forest fragment offered to local people. Instead, a larger choice of tree species, including native ones, should be proposed. The cultivation of this diverse mix would allow people to take a more active part in the preservation and restoration of natural capital at the landscape scale and could enlarge the range of benefits obtained from trees that they plant. RESUME A Madagascar, il est crucial de repondre au double imperatif de proteger la nature et d’assurer des moyens de subsistance aux populations. Analalava, ou se situe un fragment de foret secondaire degradee de la cote Est, a cote de Foulpointe, beneficie d’un statut de protection depuis 2006. La conservation a long terme de la biodiversite de ce site ne peut etre garantie sans la participation des populations. Etant donne l’acces restreint des populations a l’interieur de l’aire protegee pour l’exploitation du bois, la gestion des sources d’approvisionnement en bois de construction a l’exterieur du site represente un trait d’union entre la conservation de la biodiversite et les benefices fournis aux Hommes par les services ecosystemiques. Nous avons determine et caracterise les relations entre ces populations locales et les especes d’arbres qu’elles utilisent. Cette etude pourrait constituer une base a la mise en place d’une cooperation qui satisferait a la fois aux objectifs de conservation de la biodiversite et de developpement rural durable et equitable. Nos resultats montrent que pour les populations locales, le bois de differentes especes d’arbres, indigenes ou introduites, presente un interet pour la construction. En outre, les personnes interrogees ont montre une connaissance detaillee des traits sylvicoles d’un grand nombre d’especes. Devant la complementarite des especes indigenes et introduites en termes de proprietes et d’usages, nous concluons que la distribution gratuite de plantules d’especes introduites a croissance rapide ne devrait pas etre la seule alternative offerte aux populations locales a l’exploitation du fragment de foret protegee. Au lieu de cela, un choix plus large d’especes d’arbres, y compris d’especes indigenes, devrait etre propose. La plantation d’un melange de diverses especes permettrait ainsi aux populations de prendre part de maniere plus importante a la preservation et la restauration du capital naturel a l’echelle du paysage, et pourrait etendre la gamme de benefices qu’ils retirent des arbres plantes.

Who wants to conserve remaining forest fragments in the Manompana corridor?

Contiguous forests in Madagascar are continuously converted into forest fragments due to deforestation, and dispersed into landscape mosaics dominated by agriculture. These fragments are of increasing importance for biodiversity conservation as well as for the well being of rural inhabitants, providing a high diversity of timber and non - timber forest products. An increasing number of international projects are therefore trying to preserve remaining forests and to transfer the management of these forests to local communities. However, it is not known how important the preservation of forest fragments are to local people. We therefore explore the importance of forest fragments as a source of cash income to different groups separated by wealth level and access to forest resources. A multi - method research approach was taken, based on score application exercises as well as interviews with individual households and focus groups. Our study site was located at the east coast of Madagascar in the Manompana corridor. Results show that some groups are significantly more interested in the preservation of forest fragments than others. Interest is significantly related to the wealth of local inhabitants as well as to the walking distance between villages and forest resources. Nevertheless, interest in resource preservation does not depend on how important fragments are to local people, but rather on the awareness about resource scarcity.

Reproductive phenology of the tomato frog, Dyscophus antongili , in an urban pond of Madagascar's east coast

Based on daily monitoring around an urban pond in the coastal town of Maroantsetra, from 2003-2011, we provide an analysis of the yearly reproductive activity of the tomato frog ( Dyscophus antongilii ), a large-sized and prominent red-coloured microhylid frog from north-eastern Madagascar. Frogs were observed all year round but despite the limited climatic seasonality in the region it was possible to identify a high activity period between January-May and a lower activity period between June-December. Freshly laid eggs were found in all months except November, and with highest incidence between January and May, while calling was heard in all months. We found a positive correlation between daily adult counts and minimum air temperature. On the contrary rainfall did not significantly predict activity, although boosts of calling and egg-laying especially in the austral winter were observed after heavy rainfall events. We define D. antongilii in Maroantsetra as a sporadic wet season breeder that reproduces at irregular intervals following heavy rain events.

A new microendemic frog species of the genus Blommersia (Anura: Mantellidae) from the east coast of Madagascar

A new microendemic frog species of the genus Blommersia (Anura: Mantellidae) from the east coast of Madagascar