Mercury May Pose Higher Ecological and Human Health Risks than Lead in Vegetables Cultivated on Solid Wastes Dumpsites Soils.

Vegetable cultivation on solid wastes dumpsites (SWD) soils is very common in developing countries though unsafe due to heavy metals pollution. In order to evaluate the ecological and human health risks of this practice, Talium triangulare and Lycopersicon esculentum were grown in a greenhouse on soils from two abandoned and active SWD, and control site. The SWD soils were acidic (pH 6.

Combinations of cypermethrin and dimethoate alter behavior, hematology and histology of African Catfish, Clarias gariepinus.

Cypermethrin and dimethoate are pesticides frequently used in agriculture to eliminate pests. Contemporaneity of these and other pesticides in commercial preparations and several aquatic ecosystems is well known, though poorly studied. This study aims to evaluate the effect of sublethal concentrations of combinations of cypermethrin and dimethoate on juvenile catfish, Clarias gariepinus, given that the pesticides concomitantly occur in the floodplains were the fish breed.

Evaluating Heavy Metals Pollution and Exposure Risk Through the Consumption of Four Commercially Important Fish Species and Water from Cross River Ecosystem, Nigeria.

In order to evaluate heavy metals exposure risk in the mid-Cross River, the concentrations of iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), lead (Pb) and chromium (Cr) in water and four commercially important fishes (Chrysichthys nigrodigitatus, Clarias anguillaris, Tilapia zillii and Mormyrus rume) were studied between February 2015 and August 2016. Iron (2.71 ± 0.

Organ-dependent response in antioxidants, myoglobin and neuroglobin in goldfish (Carassius auratus) exposed to MC-RR under varying oxygen level.

Cyanobacterial bloom, a common phenomenon nowadays often results in the depletion of dissolved oxygen (hypoxia) and releases microcystin-RR (MC-RR) in the water. Information on the combined effects of MC-RR and hypoxia on the goldfish is lacking, therefore, this study is aimed at evaluating the effect of two doses of MC-RR on the antioxidants and globin mRNA of goldfish under normoxia, hypoxia and reoxygenation. The result showed that MC-RR at both doses (50 and 200 μg kg(-1) body weight) significantly (p<0.

Seasonal dynamics of phytoplankton in two tropical rivers of varying size and human impact in southeast Nigeria.

Phytoplankton occurrence and dynamics in rivers are mainly shaped by hydrophysical conditions and nutrient availability. Phytoplankton main structuring factors have been poorly studied in West African rivers, and this study was undertaken to identify these conditions in two tropical rivers that vary in size and human impact. For this, environmental variables and phytoplankton monthly samples were collected from the middle reaches of Asu and Cross rivers during an 18 months survey from March 2005-July 2006.

Age, growth and mortality of Clarias gariepinus (Siluriformes: Clariidae) in the Mid-Cross River-Floodplain ecosystem, Nigeria.

Clarias gariepinus is a threatened highly prized species used for some elite ceremonies by the local communities. Artisanal fishers take advantage of this species annual breeding migration from the lower Cross River to the floodplain lakes in Mid-Cross River during the rainy season, and some migrant stocks are not able to spawn. Since there is a lack of information on this species population dynamics in the Mid-Cross area, this study aimed to evaluate the age, growth and mortality to support the development of effective management plans.

Seasonal variation and diversity of rotifers in Ehoma lake, Nigeria.

The zooplankton and physicochemistry of Ehoma lake were studied from March 2005 to August 2006 in order to evaluate seasonal trend in species composition and abundance in relation to water quality. Forty two (42) species of rotifers dominated by Keratella tropica tropica were encountered. Species richness declined by nearly 50% from dry season values during the rainy season.