Occurrence of heavy metals in selected fish species of River Oli, Kainji Lake National Park, Nigeria

Heavy metals have long been documented as serious pollutants of the aquatic system because its contamination may have devastating effects on the ecological stability of the receiving environment. Therefore, this study assessed the concentration of heavy metals in three selected fish species from River Oli in Kainji Lake National Park to ensure continuous safety for sustainable production within the protected area. Nine sub-adult specimens, three each of Lates niloticus (Nile perch), Hydrocynus forskalii, (Tiger fish) and Synodontis membranacea (Upside-down catfish) were caught monthly using set gill nets for three months. All samples were labeled, processed and analyzed using Atomic Absorption Spectrophotometer. The result revealed that gills, bones, and muscles of the sample species contain significantly varying (p<0.05) concentration of Fe, Pb, Cu, Zn, Cr, and Cd. The highest mean concentration of Pb (4.80±0.12), Zn (24.46±4.33) and Cu (29.55±1.15) were found in H. forskalii flesh muscles also. There is significant (p<0.05) high level of Pb (2.65±0.04) bioaccumulation in the gill of H. forskalii while Cr (17.00±0.21) is higher in S. membranacea gills. The highest concentrations of Pb (4.05±0.03), Cr (11.55±0.56) and Cu (31.85±1.04) were again recorded in S. membranacea bones, while Fe (232.04±9.88) and Zn (39.35±1.24) highly accumulated in the vertebral bone of L. niloticus and H. forskalii, respectively. The concentrations of Pb and Fe in the whole fish of all sampled species are above maximum permissible limit according to the WHO standard for foods. Heavy metal elements in L. niloticus and H. forskalii have similar association pattern of Fe>Zn>Cu> Cr>Pb>Cd which slightly differ from Fe>Cu>Zn>Cr>Pb>Cd obtained for S. membranacea. This study revealed that fish can bio accumulate these heavy metals in different body parts from polluted water, whichmay lead to ecological adversity as result of impairment or loss of natural population

Human Settlement Encroachment in Kainji Lake National Park, Nigeria

Land encroachment is severely degrading and destroying many of Nigerian protected area as a result of high population pressure caused by high population growth and immigrations trends. Therefore, this study aimed at assessing human settlement encroachment in Kainji Lake National Park in order to established the extent to which this threat have been upheld and therefore call for park management to seek for proper approaches to deal with it. Data for this study were collected through the administration of questionnaire to the villages adjacent to Borgu sector of Kainji Lake National Park. Seven (7) randomly selected villages, namely Luma, Kuble, Audu Fari, Kali, Malale, Leshegbe and Gada Oli were surveyed. The result indicates gender of respondents where 65.09% of the responses were received from males while 34.91% from females suggesting that responses are the views from both gender parties who are mostly (33.96%) within the age range of 31–40 years and are predominantly farmer (43.42%). 88% of the respondents’ indicated that increased need of land for developments are the major causes of encroachment around the park while other human activities such as farming, deforestation and grazing of domesticated animals, by encroaching to protected areas have led into competition over natural resources. It is also established by 92% of the respondents agree that migration of people for livelihood support has led to increased competition between people and wildlife hence, this increase in population has consequently led to encroachment into the park as attested by a whopping 100% of the respondents. Kainji Lake National Park management need to do more in sensitizing the local communities on importance of wildlife conservation as most (54%) locals disagreed to awareness of conservation education and engages in intense vigilance against encroachment into the park land

Nutritional and anti-nutrient composition of Karaya gum tree (Sterculia setigera) seed: a potential fish feed ingredient

The nutritional and anti-nutritive composition of Karaya gum tree (Sterculia setigera) seed collected from Federal College of Wildlife Management estate, New Bussa, Nigeria was evaluated from October to December, 2013 with the aim of providing data that will guide the effective utilization and inclusion of this under exploited tropical plant seed in fish feed formulation. The seeds were washed, dried, grounded and analyzed for the proximate composition, vitamin and mineral contents as well as the anti-nutritive factors using standard procedures. The result showed that the mean values for the proximate composition were: moisture 5.20%, ash 3.95%, fat 26.03%, fiber 6.15%, protein 13.39% and carbohydrate 45.27%. The plant also contained vitamins and relatively adequate essential mineral elements of nutritional importance of macro elements such as calcium, potassium, sodium, magnesium and micro elements of iron, manganese, zinc and copper. Some anti-nutritional factor such as; alkaloids, phytate, cardiac glycosides, flavonoids, steroids and trace of oxalate were also found in the plant, but their composition will pose no serious  nutritional problem if well processed before its inclusion in fish diet and could therefore be a cheap source of raw materials for the fortification applications in various fish feed formulations