Impact of heavy metals on bacterial communities from mangrove soils of the Mahanadi Delta (India)

This study aimed to assess soil nutrient status and heavy metal content and their impact on the predominant soil bacterial communities of mangroves of the Mahanadi Delta. Mangrove soil of the Mahanadi Delta is slightly acidic and the levels of soil nutrients such as carbon, nitrogen, phosphorous and potash vary with season and site. The seasonal average concentrations (g/g) of various heavy metals were in the range: 14810-63370 (Fe), 2.8-32.6 (Cu), 13.4-55.7 (Ni), 1.8-7.9 (Cd), 16.6-54.7 (Pb), 24.4-132.5 (Zn) and 13.3-48.2 (Co). Among the different heavy metals analysed, Co, Cu and Cd were above their permissible limits, as prescribed by Indian Standards (Co=17g/g, Cu=30 g/g, Cd=3-6 g/g), indicating pollution in the mangrove soil. A viable plate count revealed the presence of different groups of bacteria in the mangrove soil, i.e. heterotrophs, free-living N-2 fixers, nitrifyers, denitrifyers, phosphate solubilisers, cellulose degraders and sulfur oxidisers. Principal component analysis performed using multivariate statistical methods showed a positive relationship between soil nutrients and microbial load. Whereas metal content such as Cu, Co and Ni showed a negative impact on some of the studied soil bacteria.

Mercury exposure Aasessment in fish and humans from Sundarban Mangrove Wetland of India

Present study had documented total mercury levels in six commonly consumed fish species, and performed across-sectional study on local residents to gauge their intake of fish (via dietary survey) and mercury exposure (via hair biomarker analyses). Mean total mercury content in edible composites of locally-caught fishes (topse, hilsa, mackerel, topse, sardinella, khoira) was low and ranged from 0.01 to 0.11 mu g g(-1) mercury, dry weight. In a cross-sectional study of 58 area residents, the mercury content in hair ranged from 0.25 to 1.23 mu g g(-1), with a mean of 0.65 +/- 0.23 mu g g(-1), Flair mercury level was not influenced by gender, age, or occupation. Mean number of meals consumed per week was 3.1 +/- 1.1, and all participants consumed at least one fish meal per week. When related to fish consumption, a significant positive association was found between number of fish meals consumed per week and hair mercury levels.

Factors affecting distribution of fish within a tidally drained mangrove forest in the Andaman and Nicobar Islands, India

Mangrove forests in meso-tidal areas are completely drained during low tides, forming only temporary habitats for fish. We hypothesised that in such temporary habitats, where stranding risks are high, distance from tidal creeks that provided access to inundated areas during receding tides would be the primary determinant of fish distribution. Factors such as depth, root density and shade were hypothesised to have secondary effects. We tested these hypotheses in a tidally drained mangrove patch in the Andaman Islands, India. Using stake nets, we measured fish abundance and species richness relative to distance from creeks, root density/m(2), shade, water depth and size (total length) of fish. We also predicted that larger fish (including potential predators) would be closer to creeks, as they faced a greater chance of mortality if stranded. Thus we conducted tethering trials to examine if predation would be greater close to the creeks. Generalised linear mixed effects models showed that fish abundance was negatively influenced by increasing creek distance interacting with fish size and positively influenced by depth. Quantile regression analysis showed that species richness was limited by increasing creek distance. Proportion of predation was greatest close to the creeks (0-25 m) and declined with increasing distance. Abundance was also low very close to the creeks, suggesting that close to the creeks predation pressure may be an important determinant of fish abundance. The overall pattern however indicates that access to permanently inundated areas, may be an important determinant of fish distribution in tidally drained mangrove forests.

Imminent Geologic and Hydrologic Hazards on Fort Ord BLM Land

The Bureau of Land Management acquired 7,500 acres of land as part of the re-use of the decommissioned Fort Ord Army base. A variety of geologic hazards exist on the landscape including gully erosion, mass wasting, and decaying earthen dams. This short report highlights a few critical areas that deserve closer evaluation and remediation. Of particular concern are decaying earthen dams and mass wasting of tall stream banks that may impact BLM infrastructure or adjacent urban development. (Document contains 13 paGES)

Some experiments on commercial pond fish culture in the tidal mangrove area of Niger delta of Nigeria

A pilot fish culture project was initiated by Shell Petroleum Development Company of Nigeria Limited in 1981 with specific aims and objectives. Site selection, survey, pond construction method and fish production with regards to experiences gathered and gained, problems and solutions so far obtained are discussed. Trials of freshwater fish species to check their adaptability to brackishwater ponds were carried out and the promising results of the growth rate of these species when compared with the traditional local brackishwater species selected for culture are reported. The extension programme so far carried out is briefly described

The incidence of Nypa fruticans (Wurmb) and its impact on fisheries production in the Niger Delta mangrove ecosystem

Nypa fruticans occurs in Bayelsa, Rivers, Akwa Ibom and Cross River State, Nigeria; invading an estimated area of 821 Km super(2) mangrove dominated swamps. Human activities such as tree felling, urbanization, oil and gas exploration and exploitation and other activities led to the interference in the normal mangrove by the Nypa palm. Lack of utilization by the local population of the Nypa palm as in into-pacification has increased the population over the years. The effect includes the reduction in primary and secondary productivity, disruption of food chain and erosion of riverbanks. The eradication of the Nypa palm from the Niger delta mangrove ecosystem and replacement with red and white mangroves will restore the ecosystem health and enhance biological diversity

Tympanotonus fuscatus - its potential and abundance in the mangrove swamps of the upper Bonny River, River State

The Shellfish Tympanotonus fuscatus fisheries was studied in the upper Bonny River of River State. Abundance and size distribution were evaluated through collection of the Shellfish from 4 sampling stations along the River System. Shell size differences were observed between the sampling stations. The periwinkles, which were harvested heavily by local women, were smaller. The results do suggest that the population of Tympanotonus fuscatus in the Mangrove swamps of the upper Bonny River Creeks are strongly influenced by the harvesting

Studies on the condition factor of the Sierra Leone mangrove oyster (Crassostrea tulipa)

Sierra Leone is a tropical country where water temperatures are high throughout the year. Consequently the local oysters tend to spawn the year round, with one or two spawning peaks. The condition of such tropical oysters may not be as high as those oyesters in temperate countries since the stored glycogen is regularly utilized to form gonads. A high condition factor value indicates that the oysters have accumulated glycogen and or gonads, whereas a low condition factor value indicates that the oysters have spawned and are in the process of accumulating glycogen, which may later be utilized for gonad development. In oyster culture, condition factor studies may be supported by plankton and oyster spat settlement studies in the culture area. These studies give an indication of when oyster larvae and spat settlement are at their peak values. In Sierra Leone studies of the plankton and spat settlement are undertaken every week throughout the year. Conditions factor is obtained from the ratio weight of dry (oyster) meat x 1000/internal volume. Detailed condition factor values are shown in relation to salinity at two stations. Condition factor declines with reducing salinity, which principally occurs during the rainy season. The best times to collect spat are May to June and September to October

Climate change and its risk reduction by mangrove ecosystem of Bangladesh

Climate change is amongst the most dreaded problems of the new millennium. Bangladesh is a coastal country bounded by Bay of Bengal on its southern part and here natural disasters are an ongoing part of human life. This paper discusses about the possible impact of climate change through tropical cyclones, storm surges, coastal erosion and sea level rise in the coastal community of Bangladesh and how they cope with these extreme events by the help of mangrove ecosystem. Both qualitative and quantitative discussions are made by collected data from different research work those are conducted in Bangladesh. Mangrove ecosystem provides both goods and services for coastal community, helps to improve livelihood options and protect them from natural disaster by providing variety of environmental support

Estudo clínico randomizado duplo cego comparando duas técnicas de plicatura nasal após osteotomias tipo Le Fort I

A correção de deformidades esqueléticas da face por meio de um tratamento ortodôntico-cirúrgico tornou-se uma opção segura e previsível. Os movimentos ósseos são milimetricamente calculados e executados cirurgicamente, assim como a oclusão é meticulosamente engrenada através dos movimentos ortodônticos. Os efeitos que os tecidos moles sofrem com as cirurgias ortognáticas são, no entanto, menos previsíveis, e apesar do principal objetivo da cirurgia ortognática ser uma melhora funcional, o componente estético é sem dúvida de extrema importância. Em especial, a região de base alar apresenta resultados muito variáveis, a despeito dos bons resultados esqueléticos atingidos. O objetivo deste estudo foi comparar 2 diferentes tipos de sutura utilizados na região de base do nariz, e observar qual tipo apresenta um resultado que melhor acompanhe os movimentos realizados pelo tecido esquelético. Trinta e cinco pacientes foram aleatoriamente distribuídos em 2 grupos. O grupo 1 funcionou como controle e os pacientes receberam a plicatura nasal intra-oral, que é o tipo de plicatura nasal mais descrito na literatura. Já os pacientes do grupo 2 receberam plicatura nasal extra-oral. Para análise estatística foram calculadas as médias e desvios padrões dos grupos, e a hipótese nula de que não havia diferença entre os 2 grupos foi testata com o teste T de Student. Em ambos os grupos ocorreu um alargamento da base do nariz, porém a média de alargamento do grupo 1 foi de 2,50 milímetros (mm), enquanto que a média de alargamento do grupo 2 foi de 1,26 mm. Além disso, o desvio padrão foi menor para o grupo 2, e a hipótese nula foi rejeitada (p<0,05), demonstrando que a diferença entre os grupos foi estatisticamente significativa. Pôde-se concluir que quando objetiva-se um controle mais previsível e rigoroso da base do nariz, a plicatura nasal extra-oral cumprirá melhor esta função.

Concentrations en métaux toxiques chez Crassostrea gasar (huître de mangrove) en zone urbaine lagunaire d'Abidjan (Côte d'Ivoire)

This paper presents results related to a study of toxic heavy metals concentrations (Cd, Cu, Hg and Zn) in Crassostrea gasar (mangrove oyster). A comparative study is made between samples collected in urban region (Abidjan) and those from rural areas (Assinie-Mafia and Assouindé). Toxic metals concentrations in oyster samples collected in urban zone are higher than those in rural samples, as a result of chemical pollution due to urban and industrial wastes. Correlations between pollutants-weight of organisms and pollutants are good.