39 research outputs found

    Impacts of Climate Change on Small Pelagic Fish Catches in the Coastal Artisanal Fishers Communities of Tanzania

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    Climate-related effects occur across all regions in Tanzania, affecting primary sectors such as agriculture and fishing. This study investigated the impacts of climatic change on small pelagic catches in fishers in Kilindoni, Kipumbwi and Kilwa Kivinje villages along the Tanzanian coast. We studied how changes in rainfall, sea surface temperature, wind speed and chlorophyll a affect small pelagic fisheries using primary and secondary data. Qualitative and quantitative methods were applied. Primary data collection involved questionnaires, focus group discussions and key informant interviews. Secondary data was obtained from Tanzania Meteorological Agency and remote sensing from Modi's sensor. Results showed an increase in sea surface temperature (tau = 0.0151, 0.0121, 0.0238 for Kilindoni, Kilwa Kivinje and Kipumbwi, respectively) and unpredictable changes in rainfall patterns which affected small pelagic fisheries. The average rainfall was 284.6, 97.5 and 56.4 mm in Kilindoni, Kilwa Kivinje and Kipumbwi, respectively. In recent years, rain has been unreliable compared to the past 20 years. Unpredictable rainfall, increased sea surface temperature, wind speed and chlorophyll a had negatively impacted the small pelagic fishery. There was a strong relationship between the decline of small pelagic catches and climatic variables. The findings of this study have implications for coastal fisher's livelihood, income and food security. Keywords:  Coastal communities; small pelagic fishery; climate change; fisheries; livelihoo

    Effects of Rhizobium inoculation and Supplementation with P and K, on Growth, Leaf chlorophyll content and Nitrogen Fixation of Bush bean varieties

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    This research article was published by American Journal of Research Communication in 2017Low crop productivity is a general problem facing most farming systems in sub-Saharan Africa (SSA). These low yields are pronounced in grain legumes and are often associated with declining soil fertility and reduced N2-fixation due to biological and environmental factors. Biological nitrogen fixation (BNF), a key source of N for farmers using little fertilizer, constitutes one of the potential solutions and plays a key role in sustainable grain legumes production. Phosphorus is needed in relatively large amounts by legumes for growth and has been reported to promote legumes growth and yield, nodule number and nodule mass in different legumes. Potassium influences the water economy and crop growth through its effects on water uptake, root growth, maintenance of turgor, transpiration and stomatal regulation. Various Studies have shown that Rhizobium inoculation, phosphorus and potassium has the potential to improve legumes growth, seed yield, nitrogen fixation and also nutrient up take of legumes. The potential role of rhizobia inoculants and supplementation of P an K with respect to growth, nitrogen fixation, nutrient uptake, total leaf chlorophyll content, and grain yield of legumes are given attention in this review

    Wanted dead or alive : high diversity of macroinvertebrates associated with living and ā€™deadā€™ Posidonia oceanica matte

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    The Mediterranean endemic seagrass Posidonia oceanica forms beds characterised by a dense leaf canopy and a thick root-rhizome ā€˜matteā€™. Death of P. oceanica shoots leads to exposure of the underlying matte, which can persist for many years, and is termed ā€˜deadā€™ matte. Traditionally, dead matte has been regarded as a degraded habitat. To test whether this assumption was true, the motile macroinvertebrates of adjacent living (with shoots) and dead (without shoots) matte of P. oceanica were sampled in four different plots located at the same depth (5ā€“6 m) in Mellieha Bay, Malta (central Mediterranean). The total number of species and abundance were significantly higher (ANOVA; P<0.05 and P<0.01, respectively) in the dead matte than in living P. oceanica matte, despite the presence of the foliar canopy in the latter. Multivariate analysis (MDS) clearly showed two main groups of assemblages, corresponding to the two matte types. The amphipods Leptocheirus guttatus and Maera grossimana, and the polychaete Nereis rava contributed most to the dissimilarity between the two different matte types. Several unique properties of the dead matte contributing to the unexpected higher number of species and abundance of motile macroinvertebrates associated with this habitat are discussed. The findings have important implications for the conservation of bare P. oceanica matte, which has been generally viewed as a habitat of low ecological value.peer-reviewe

    Effect of season and leaf species type on mangrove leaf Consumption by grapsid crabs

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    Changes in Sediment Fatty Acid Composition during Passage through the Gut of Deposit Feeding Holothurians: Holothuria atra (Jaeger, 1883) and Holothuria leucospilota (Brandt, 1835)

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    Sea cucumbers Holothuria atra and Holothuria leucospilota play an important role in the bioturbation of sediment in coral reef and rocky intertidal ecosystems. This study investigated changes in sediment fatty acid (FA) composition during gut passage in H. atra and H. leucospilota. The FA composition did not differ significantly between species. Comparison of FA composition in ambient sediment (AS), foregut (FG), midgut (MG), hindgut (HG), and faecal pellets (FPs) indicated that marked changes in FA composition occurred during passage through the gut of H. atra and H. leucospilota. Saturated fatty acids (SAFAs), monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), and branched fatty acids (BrFAs) were significantly higher in FG than in AS, suggesting that both species selectively ingested nutrient rich particles. Significant reduction of SAFAs, MUFAs, PUFAs, and BrFAs occurred in MD and HD, with complete elimination of most PUFAs in FPs. A decrease in PUFAs 20:5Ļ‰3, 18:4Ļ‰3, 22:5Ļ‰3, 22:6Ļ‰3, 18:2Ļ‰6, 18:3Ļ‰3, 18:3Ļ‰6, odd-numbered BrFAs, and MUFA 18:1Ļ‰7 indicated that algal detritus and bacteria were important part of diet. These results have implications for the fate of specific dietary FAs, especially Ļ‰3 and Ļ‰6, and the contribution holothurian FPs make to the FA composition of coral reef and rocky intertidal ecosystems

    Effect of Rhizobium inoculation and supplementation with phosphorus and potassium on growth and total leaf chlorophyll (Chl) content of bush bean Phaseolus vulgaris, L.

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    This research article was published by Scientific Research Publishing in 2014The study was conducted to investigate the effect of Rhizobium inoculation and supplementation of phosphorus and potassium on growth and total leaf chlorophyll content to the three released bush bean varieties in northern Tanzania. To achieve this aim, the glasshouse experiment was conducted at Nelson Mandela African Institution of Science and Technology while field experiment were carried out at Tanzania Coffee Research Institute, in Kilimanjaro, Tanzania between April July 2014. The experiment was laid out in factorial arrangement. Factor I comprised of three bush bean varieties. Factor II involved two inoculation treatments viz 1) inoculation with Rhizobium spp. and 2) without inoculation. Factor III included four fertilizer levels (0 Kgāˆ™haāˆ’1 20 Kg K haāˆ’1, 30 Kg P haāˆ’1 and 20 kgāˆ™K + 30 Kg P haāˆ’1). Both screen house and field experiments were replicated four times. Plant growth parameters (plant height (cm), number leaves per plant, stem girth (mm)) were measured at 2, 4 and 6 weaks after planting (WAP). The chlorophyll was extracted by using Dimethylsulphoxide (DMSO) and absorbance was determined at 645 and 663nm using UV/Visible spectrophotometer. Results showed that Rhizobium application significantly improved the num ber of leaves per plant, plant height, pant girth and total leaf chlorophyll content. Furthermore, compared with the zero treatment control, potassium fertilization significantly increased the num ber of leaves per plant, plant height, pant girth and total leaf chlorophyll content of the three va rieties. In general, these parameters were significantly increased with phosphorus supplied at 30 kg/ha. The combination of these supplies at different levels resulted in significant interactions in some parameters and thus indicating need for these inputs in the study area
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