39 research outputs found
Impacts of Climate Change on Small Pelagic Fish Catches in the Coastal Artisanal Fishers Communities of Tanzania
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
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 ādeadā Posidonia oceanica matte
The Mediterranean endemic seagrass Posidonia
oceanica forms beds characterised by a dense leaf canopy
and a thick root-rhizome āmatteā. Death of P. oceanica
shoots leads to exposure of the underlying matte, which
can persist for many years, and is termed ādeadā 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 (5ā6 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
Changes in Sediment Fatty Acid Composition during Passage through the Gut of Deposit Feeding Holothurians: Holothuria atra (Jaeger, 1883) and Holothuria leucospilota (Brandt, 1835)
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 20:5Ļ3, 18:4Ļ3, 22:5Ļ3, 22:6Ļ3, 18:2Ļ6, 18:3Ļ3, 18:3Ļ6, odd-numbered BrFAs, and MUFA 18:1Ļ7 indicated that algal detritus and bacteria were important part of diet. These results have implications for the fate of specific dietary FAs, especially Ļ3 and Ļ6, 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.
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 Kgāhaā1 20 Kg K haā1, 30
Kg P haā1 and 20 kgāK + 30 Kg P haā1). 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