This study evaluated the phytoplankton community of Taylor creek from Polaku to Agbia between November 2013 and July 2014. Sampling was carried out in 12 locations along the stretch of the creek following standard protocol. The phytoplankton enumeration was done and identified accordingly. In all the 12 locations, 100 species of phytoplankton belonging to 14 taxonomic groups including Bacillariophyta (31 species), Chlorophyta (25 species), Pyrrophyta (4 species), Cyanophyta (17 species), Spermatophyta (9 species), Euglenophyta (3 species), Phaeophyta (1 species), Heterokontophyta (2 species), Myxophyta (1 species), Xanthophyta (1 species), Chrysophyta (2 species), Lycopodiophyta (1 species), Cryptophyta (1 species), Dinophyta (2 species). Bacillariophyta, Chlorophyta, Cyanophyta and Spermatophyta with occurrence rate of 36%, 34%, 10% and 10%, respectively were the predominant phytoplankton in the study area occurring in all the locations across the period of the study. The various species have some distinct environmental condition that enable them thrive in their niche, and this determines the structure of the phytoplankton in the study area. The diversity indices provided information about the distribution and health condition of the creek. The study showed significant relationships between Shannon-Wiener, Menhinick, Margalef, equitability and Fisher-alpha indices. The ecosystem showed moderate to heavy pollution based on Shannon Wiener index. There is the need for improved method of waste disposal and other anthropogenic activities being carried in and/ or within the creek. 折りたたむ

This study evaluated the behavioural response and toxicity of paraquat dichloride to fingerlings of Clariasgariepinus. The fishes were acclimatized for 14 days and exposed to sublethal concentration of 0.00 ppm, 16.56 ppm, 22.08 ppm, 27.60 ppm, 33.12 ppm and 38.64 ppm. A 24 hours’ renewal bioassay was adopted in this study. Results showed that the fishes exhibited change in swimming, opercular movement, body pigmentation, surfacing and air gulping. Mortality rate increased significantly at p<0.05 as the concentration of the toxicant increased as well as the exposure period. LC50 values at 24, 48, 72 and 96 were 59.95, 47.59, 38.12 and 26.18ppm, respectively. Based on the results, Paraquat dichloride users need to discard the remains of empty cans properly to avoid contamination. Also there is need to exercise caution when using paraquat dichloride based herbicides in agricultural fields close to surface water resources. 折りたたむ

Aminoforce containing 720g/l of 2,4-dimethylamine salt induced changes on some enzymes and electrolytes in the male Oryclotagus cuniculus (New Zealand rabbit) were assayed. The organisms were exposed to varying sub-lethal concentrations of the toxicant (720g/l). The concentrations were prepared by pipetting 0.4mls, 0.8mls and 0.12mls making it up to 1.5L clean water in a metal container to make 2.0 mgl-1, 4.0 mgl-1 and 6.0 mgl-1. Aspartate amino transferase (AST), Alanine amino transferase (ALT) and Acid phosphatase (ACP) were assayed in the liver and blood. Results showed that aspartate amino transferase values in the liver and blood were significant (p<0.05) across the concentration of the toxicants. Aspartate amino transferase increased as the concentration of the toxicant increased in the liver, and decreased as the toxicant concentration increased in the blood. Alanine amino transferase in the blood and liver were akin to AST while ACP values increased in the blood and decreased in the liver as the concentration of the toxicant increased. Electrolytes (Sodium (Na+), potassium (K+) and magnesium (Mg2+) ions) showed statistical deviation across the various concentration of the toxicants. Chloride ion values stabilized in the experimental group being not significantly different (p>0.05) across the various concentration of the toxicants. From the study, AST, ALT and ACP are suitable biomarkers for showing sub-lethal effect of aminoforce on Oryclotagus cuniculus. The effects recorded clearly unveiled the potential effect of this xenobiotics on Oryclotagus cuniculus. Therefore, exposure of Oryclotagus cuniculus to this toxicant will affect the organism’s physiological responses and over prolong period of time it could lead to death. Additionally, via food chain man may be affected. The use of this toxicant close to rabbittory should be done with utmost caution. 折りたたむ

In spite of the popularity of open-air waste dumping in Nigeria, it remains a relatively less effective waste management option across the globe because of its associated environmental impacts which includes the release of green house gases (GHGs), persistent organic pollutants (POPs), and metal micro-pollutants amongst others. This study aims to assess the potential environmental risks associated to metals released and vertically delineated across the soil profile within surroundings of dumpsite. Heavy metals in soil samples were acid-digested using the aqua-regia mixture of hydrochloric and nitric acid, followed by instrumentation analysis using the GBC 908 PBMT model atomic absorption spectrophotometer. Contaminated sites showed metal concentrations ranging from 1.493 to 109.460 mg/kg, 0.133 to 4.237 mg/kg, and 5.200 to 25.367 mg/kg for lead, cadmium and chromium respectively, with location 1 land area showing the most contamination. Only soil chromium was observed within regulatory stipulations in all cases. There was significant variation (p < 0.05) between the different sample locations, thereby indicating variations in composition of dumped wastes. Lead and cadmium showed the strongest positive correlation (r = 0.855, p < 0.01) and the application of some heavy metal pollution indicators revealed relatively higher metal loads and degree of contamination, as well as depicting potential ecological risk for soils of location 1. The significant heavy metal contamination of soils in the Tombia-Amassoma waste dumpsite requires that the local environmental sanitation and regulatory authorities take necessary remedial action to forestall the escalation of public health concerns that may emanate from this open-air dump. 折りたたむ