Rivers State University of Science and Technology

About: Rivers State University of Science and Technology is a education organization based out in Port Harcourt, Rivers, Nigeria. It is known for research contribution in the topics: Population & Threatened species. The organization has 1826 authors who have published 1833 publications receiving 15183 citations.

Study of Heavy Metal Distribution in Soils Impacted with Crude Oil in Southern Nigeria

Abstract: The study presents the levels and enrichment factors of heavy metals in soils of southern Nigeria that have received significant impact of crude oil spillage. The results revealed that the concentrations of heavy metals in the examined soils fitted into levels found in agricultural soils except for cadmium. Heavily impacted sites showed elevated levels of heavy metals compared to less impacted sites and background levels. The mean enrichment factors for Cd, Cu, Cr, Pb, Mn, Ni, and Zn were 37.3, 2.8, 14.4, 14.0, 0.77, 5.4, and 1.27 for topsoil and 37.5, 1.30, 7.81, 1.59, 4.12, and 1.28 for subsoil, respectively. This clearly indicates that there is gradual build-up of heavy metals in these soils as a result of the oil spillage and related anthropogenic activities in this area.

The fish assemblage of the lower Bonny river, Niger Delta, Nigeria

Abstract: Summary The fish assemblage of the lower Bonny river of the Niger delta with its adjoining creeks was studied. Local fishing gear was used in the collection of samples, which yielded 25 families made up of 57 species. Of these 25 families, some were residents of the main river (Cynoglossus senegalensis, Arius heudoloti, Pentane-mus quinquarius and Trichurus lepturus) whilst others were creek residents (e.g. Tilapia guineensis, Sarotherodon melanotheron, Citharichthys stamfii and Eleotris vittata). Higher catches were made in the dry season than in the wet season for most of the gear types employed in both the creek and the main river channel. A comparison between the creek and the main channel fish (using Sorenson's index; 0–34) suggests that the creek assemblage is separate from that of the main river channel. Resume On a etudie la population piscicole du bas de la riviere Bonny, dans le delta du Niger et dans les criques voisines. On a utilise le materiel de peche local pour recolter des echantillons. Ceux-ci ont reuni 57 especes appartenant a 25 families. Sur ces 25 families, on a observe que certaines etaient residentes de la riviere principale (Cynoglossus senegalensis, Arius heudoloti, Pentanemus quinquarius et Trichurus lepturus) alors que les autres sont des residents de la critique (e.a Tilapia guinensis, Sarotherodon melanotheron, Citharichthys stamfii et Eleotris vittata). Les prises effectuees en saison seche etaient plus importantes qu'en saison des pluies pour la plupart des types d'equipement utilises, que ce soit dans les criques ou dans le lit principal de la riviere. La comparaison des poissons de la crique avec ceux du lit principal (en utilisant l'index de Sorensen: 0,34) laisse entendre que la population piscicole de la crique est isolee de celle du lit principal de la riviere.

Mortality and quality indices of live west african hard-shell clams (galatea paradoxa born) during wet and dry postharvest storage

Abstract: Freshly harvested clams (Galatea paradoxa Born) obtained from the Cross River, Nigeria were subjected to live storage for 7 days in or outside of water. The objective was to study the effects of storage method and duration on mortality, weight changes and selected physical and physicochemical properties of the clams. Overall, 62 or 35% of the stored clams died over the 7-day duration under wet (potable water) or dry storage, respectively. No deaths were recorded in day 1 (wet storage) or in days 1-3 (dry storage). Regression analysis showed linear relationships between storage duration and each of the dependent-quality variables of weight change, density, pH and electrical conductivity (EC) evaluated under both storage methods. The regression coefficients (pl, β2) for assayed quality parameters in wet or dry storage were significantly different (P ≤ 0.05). R 2 were generally larger for dry storage than for wet storage. Initial clam weights did not significantly (P ≥ 0.05) affect weight change during storage, indicating that weight loss during dry storage was statistically invariant with clam weight. The study concludes that priority should be given to prompt sale and utilization (<3 days) of clams, particularly large clams. The use of dry storage to reduce postharvest mortality and weight losses will potentially increase the profitability of the clam industry.

Community structure and ecology of snakes in fields of oil palm trees (Elaeis guineensis) in the Niger Delta, southern Nigeria

Abstract: Aspects of community structure and ecology of snakes were studied in the years 2004–2006 in fields of oil palm trees (Elaeis guineensis) of three study areas in Southern Nigeria. A total of 284 individual snakes, belonging to twelve species of three families (seven Colubridae, four Elapidae, one Viperidae), were recorded, including both sighted and captured individuals (not including in this count the individuals that escaped before identification to species level could be made). All the study areas were nearly identical in terms of species composition. Most snakes (about 67%) were recorded during the dry season months, when the fruits of the oil palm ripe, thus attracting lots of organisms that are potential prey for snakes. The most important food items for oil palm snakes were Agama lizards, birds and rodents, but they also fed on skinks, geckos, fruit bats and tree frogs. Snakes were spotted climbing with peak frequencies occurring in the range of 16–18 m above the ground level. In general, oil palm trees within the range of 16–27 m high harboured higher number of snakes. Climbing snakes were nonrandomly positioned on the trees: the highest percentage of snakes (68%) was lodged between the leaf bases and oil palm fruit bunches. The general implications of the given data are discussed.