Environmental & Physical Sciences

Environmental & Physical Sciences Research Papers/Topics

Effects Of Environmental Variability On Fish Diversity And Composition Along The Southern Namibian Coastline During Summer

ABSTRACT Species diversity, richness and composition of fish in bottom-trawling were investigated off the Namibian coast between Oranjemund and Henties Bay. Sampling followed a systematic transects design, along latitude gradients (28-22oS) at different seafloor depths (100-500m). In total 18 transects were sampled containing 105 stations. At each trawled station the whole catch was sorted into species type and the total body mass (kg) of each fish species was recorded. A total of 91 fish spe...

An Evaluation Of The Natural Radioactivity In The Soils Of Okahandja And Karibib, Namibia

ABSTRACT The natural radioactivity and associated hazards in the soils of the towns of Karibib and Okahandja have been studied by gamma spectroscopy. Each town was divided into ten geographical areas and five soil samples were collected across each area. These samples were processed and placed in well-labelled 500 ml plastic bottles. A High Purity Germanium detector (HPGe) was used to measure the gamma ray spectra of the samples. The intensities of selected gamma lines were used to calculate ...

Effects Of Sand Mining On Land Degradation And Plant Species Diversity: A Case Study Of North B District Of Unguja Region, Zanzibar

ABSTRACT A study was carried out to assess effects of sand mining on land degradation and plant species diversity in North „B‟ district, Zanzibar based on specific objectives to: (1) investigate community perception on sand mining, (2) asses the impact of sand mining on socio-economic activities among small holder farmers,(3) determine effect sand mining on land degradation. The study also aimed (4) to determine effect of sand mining on plant species biodiversity, (5) to identify importa...

Impact Of Mine Pollution On Composition, Diversity And Structure Of Plant And Ground-Dwelling Invertebrate Communities Around Kombat Mine Tailings Dump, Namibia

ABSTRACT The impact of heavy metal pollution on vegetation and communities of ground-dwelling invertebrates was investigated at Kombat Mine tailings dump in Namibia. Sixteen transect lines were marked around the dump. Plots, 15m x 15m, were marked at 50m intervals along each transect. Top soils in the demarcated plots were sampled and analysed for concentrations of heavy metals and total sulphur. Woody plant species were identified, counted and heights measured. Herbaceous plants were identif...

Genetic Diversity Of Sorghum (Sorghum Bicolor (L.) Moench) And Its Wild Relatives In Namibia Using Ssr And Rapd Analyses

ABSTRACT Sorghum bicolor (L.) Moench is the fifth most important cereal crop in the world, and in Namibia, sorghum is the second most important. The genetic resources of sorghum remain unexplored in Namibia. This could lead to a loss of genetic diversity as wild relatives and foreign varieties could interbreed with landraces, resulting in an undesired alteration of its genetic make-up. This study was conducted to evaluate the genetic diversity among the Namibian Sorghum bicolor accessions sto...

An Evaluation Of Factors Influencing Inaccuracy In Residential Property Valuation In Lagos Metropolis

ABSTRACT Besides its other potentially grave consequences, inaccurate valuation is inimical to healthy development of the property market

Seasonal Occurrence Of Fleas And Other Ectoparasites On Small Mammals At Waterberg Plateau Park, Namibia

ABSTRACT Fleas and other ectoparasites infesting small mammals were studied from December 2005 to June 2006 at Waterberg Plateau Park, Namibia. The main aim of this study was to investigate seasonal occurrence of fleas and other ectoparasites on small mammals at selected sites at Waterberg Plateau Park. Small mammals were live-trapped, marked and released. Ectoparasites were collected (by brushing) from these small mammals before they were marked and released. Fleas, ticks and lice were store...

Occurrence And Distribution Of Fish Parasites Of Potential Threat To The Aquaculture Sector Along The Kavango River, Namibia

ABSTRACT Cichlids are subject to a wide range of diseases and parasites. Previously studies were conducted on fish parasites on the Okavango Delta, Botswana. This thesis is the first on fish parasites in the Kavango River, Namibia. The study aims to identify parasites occurring on commercially farmed fish i.e.: Oreochromis andersonii, Tilapia rendalli and Serranochromis robustus and to determine if these parasites may have potential threat to aquaculture and humans. For the purpose of identif...

Insecticide Resistance In Diamondback Moth, Plutella Xylostella L. (Lepidoptera: Yponomeuhdae) From Selected Cabbage Farms Associated With Pyrethroid And Organophosphate Use In Southern Ghana

Over dependence on insecticides for the control of diamondback moth (DBM), Plutella xylostella (L ) has resulted in development of resistant strains and health hazards due to toxic residues in cabbage. The present study was undertaken to evaluate resistance in DBM and to assess the contribution of residues of insecticides used for DBM control on resistance development. A preliminary survey conducted in Accra and Mampong-Akuapem, revealed inappropriate agronomic practices as the main cause of ...

Identifying The Influence Of Male Household Heads On The Expected Outcomes Of Enam Project Community-Based Interventions

 Background More than a decade ago, UNICEF developed a conceptual framework for malnutrition in which inadequate food intake was identified as an immediate cause of child malnutrition (UNICEF, 1997). Inadequate food intake by children is often a consequence of suboptimal child feeding practices (Latham, 1997). Optimal child feeding practices is a function of household food supply (quantity and quality) and intra-household food allocation practices. In developing countries, gender is often a...

Studies On The Biology And Chemical Control Of Amblyohha Variegatum' (Fabricius, 1794) Ticks On The Accra Plains Of Ghana

ABSTRACT In a study of the life cycle of Amblyomma variegatum under laboratory conditions of 72%±2 RH and temperature of 28°C±2, the feeding periods of larvae and nymphs on rabbits were 6-9 days and 6-13 days respectively, while that of adults on sheep was 17-19 days. The mean unfed weights of larva, nymph and adult were 0.149 x 10-3g, 0.906 X 10-3g and 28.5 x 10-3g respectively, while their mean fed weights were 2.14 x 10-3g, 48.6 x 10-3g and 2874 x 10-3g respectively. The moulting perio...

Assessment Of Selected Borehole Water Quality And Efficiency Of Homemade Water Filter Purification Devices In Mariental Rural, Hardap Region.

ABSTRACT Approximately 6.6% of Hardap Region has unsafe drinking water according to WHO (2018) guidelines. Consuming this water can cause serious illness. Three filters, namely the bucket filter, sand filter, and charcoal filters were constructed and tested for physico-chemical and bacteriological removal efficiencies. More than 500 000 people in developing countries use filters to treat drinking water. Regardless of this positive implementation, there is limited knowledge to improve its desi...

Abundance, Structure And Uses Of Baobab (Adansonia Digitata L.) Populations In Omusati Region, Namibia

ABSTRACT This study sought to determine the biology and the uses of baobab (Adansonia digitata L.) populations in Outapi and Onesi constituencies in Omusati Region, Namibia. As one of the important Non-Timber Forest Products (NTFPs)-providing species of ecological and socio-economic significance, there is need to have a better understanding of the biology and local uses of the species before its full potential and sustainable harvesting is realized. A comparison of densities, distribution pat...

The Influence Of Land Use On Plant Species Diversity In The Biosphere Area “Schwäbische Alb”, Southwest Germany

Abstract The aim of this study was to determine the relations between the intensity of land use and the characteristics of different habitat types within the grassland ecosystem in the Biosphere Area “Schwäbische Alb” in Germany. Data has been collected based on 50 examination plots (4×4 m) of the Biodiversity Exploratories project. These plots represented different land use types and levels of intensity which are 1) grazed, ungrazed 2) once, twice, three times mowed, 3) fertilised, unf...

Age Determination And Growth Rate Of The Northern Benguela Sardine (Sardinops Sagax)

Abstract The main objective of this study was to determine sardine age by counting rings on otoliths and to analyse the length, age and growth through regression and Von Bertalanffy Growth models. Otoliths amounting to 826 pairs were collected from the annual sardine research survey of the Ministry of Fisheries and Marine Resources in October 2013. A total of 713 sardine otoliths were mounted on black Perspex plates and aged by means of counting rings using a Zeiss microscope at a magnificati...


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