https://journals.unam.edu.na/index.php/ISTJN/issue/feed 2024-12-12T10:34:16+02:00 Prof. Rafael Rodríguez Puentes rpuente@unam.na Open Journal Systems <p>International Science and Technology Journal of Namibia (ISTJN) is a diamond open access, journal of peerreviewed research and commentary in pure, applied and allied sciences and technology published by the Faculty of Science, University of Namibia. Aims and Scope The journal reflects the multidisciplinary nature of the field of science and technology. It addresses the needs of multiple, interlocking communities, including methodologists in mathematics, statistics and econometrics; as well as basic and applied scientists in biology, chemistry, physics, public health, medicine, education, mining, geology, computing, food, agriculture and engineering. The journal will strive to enhance the level of methodological rigour in pure and applied sciences and will contribute to the development of methodological standards in the fields of science and technology in Namibia. In pursuing its main objective, the journal will also provide a meeting ground for researchers from a number of traditional disciplines and will foster the development of scientific research and publication especially among younger practitioners</p> https://journals.unam.edu.na/index.php/ISTJN/article/view/1956 2024-10-08T14:01:26+02:00 Mustapha Aminu aminumustapha992@gmail.com Abdulhamid Dahiru adahiru22@fudusinma.edu.ng

<p>This study was conducted to determine the concentrations of Cadmium, Cobalt, Copper, Nickel, Lead and Zinc in the Gill, Muscle and Tails of African catfish collected from Gwaigwaye, maska and Zobe dams in Katsina state, Nigeria across the dry and wet seasons. The &nbsp;&nbsp;collected tissues of African catfish were digested and analyzed for the &nbsp;toxic metals using microwave plasma atomic emission spectroscopy (MPAES). The levels of the metals obtained &nbsp;were compared with acceptable limits of world health organization(WHO) and Standard organization of Nigeria(SON).The metal levels were found in the following ranges, 0.0132±0.01 to 0.057±0.02 mg/kg for Cd, 0.00±0.00 to 0.887±0.01 mg/kg for Co, 0.090±0.00 to 0.26±0.00 mg/kg for Cu, 0.00±0.00 to 0.138±0.01 mg/kg &nbsp;for Ni, 0.00±0.00 to0.003±0.00 mg/kg for Pb and 0.133±0.04 to 0.855±0.01mg/kg for Zn for catfish gill in dry and wet seasons. Likewise, the concentration levels of the metals in catfish muscle in the following ranges were as follows 0.01±0.00 to 0.076±0.01 mg/kg for Cd, 0.00±0.00 to 0.048±0.01 mg/kg for Co, 0.066±0.04 to 0.108±0.03 mg/kg for Cu, 0.01±0.00 to 0.096±0.03 mg/kg for Ni, 0.00±0.00 to 0.01±0.00 mg/kg for Pb and 0.036±0.05 to 0.411±0.04 mg/kg for Zn . Similarly, 0.019±0.01 to 0.029±0.03 mg/kg for Cd, 0.00±0.00 to 0.091±0.01 mg/kg for Co, 0.079±0.01 to 0.133±0.03 mg/kg for Cu, 0.016±0.03 to 0.116±0.01 mg/kg for Ni, 0.00±0.00 to 0.023±0.03 mg/kg for Pb and 0.323±0.03 to1.08±0.01 mg/kg for Zn in catfish tail in both dry and wet seasons. &nbsp;The levels of the metals were found to be below the safe limits set by both WHO and SON. African catfish from gwaigwaye, maska and zobe dams are therefore safe for human consumption. The results of statistical analysis and P values&lt;0.05 indicated no significant &nbsp;&nbsp;difference &nbsp;&nbsp;between the tissues of African catfish analyzed across all the dams in both seasons.</p>

2024-12-06T00:00:00+02:00 Copyright (c) 2024 International Science and Technology Journal of Namibia https://journals.unam.edu.na/index.php/ISTJN/article/view/1986 2024-12-12T10:34:16+02:00 Simon T. Angombe sangombe@unam.na Rosemary Shikangalah rshikangalah@unam.na Ezekeil G. Kwembeya ekwembeya@unam.na

<p>National parks are important systems for protecting biodiversity and ecosystems around the world. In Namibia, approximately 19% of the country’s land surface is proclaimed for protected areas including Etosha National Park (ENP). Managing the protected areas effectively and sustainably requires a great understanding of various components of the park, including the soils. This study aimed to understand the soil properties at different water-points in ENP (at Mushara, Rietfontein and Ombika water-points). Ten plots from each site were sampled, at different soil depths. Soil parameters such as soil texture, pH, electronic conductivity (EC), Cation Exchange Capacity (CEC), phosphorus (P), potassium (K) and organic matter content (OM) were measured and analysed. The results show that soils were poorer at Mushara than at Rietfontein and Ombika, in terms of OM, Zinc (Zn), EC, Iron (Fe), and CEC. Furthermore, Mushara had significantly more sand content than both Ombika and Rietfontein. However, there were no significant differences between Rietfontein and Ombika in terms of CEC, Zn, Calcium (Ca), pH, OM, iron, manganese, sodium (Na) and soil texture. All sites were largely dominated by sandy soil. However, Mushara had significantly more sand than both Ombika and Rietfontein, and significantly lower clay and silt content than Ombika and Rietfontein. The study concludes that the soil properties at assessed water-points might be influenced by vegetation communities, soil type and the total annual precipitation. Therefore, the results of this study can be used to refine conservation strategies and develop long-term monitoring programs. We recommend that future studies focus on the link between vegetation composition, above and below ground biomass and soil properties in ENP.</p>

2024-12-13T00:00:00+02:00 Copyright (c) 2024 International Science and Technology Journal of Namibia