The composition and distribution of fish in the Ikpoba reservoir were investigated. A total of fifty-seven species of fish belonging to thirty-nine genera and twenty-three families were recorded. Of these, 46 species were recorded at the upstream station, 35 at the reservoir, 24 at the slope and 32 at the downstream station. The percentage compositions were 81%, 61%, 42% and 56% respectively. There were 21 ubiquitous species while the distribution of the other species showed variability indicating effects of habitat condition. Species diversity indices showed that the upstream section was richer, more diverse with species more evenly distributed than the other stations. Heavy metal analysis of the dominant fish species showed higher mean levels than the background levels. Metal contamination factor and bioaccumulation quotient were variable in the fishes and in the stations but followed a ranked order of 3 > 2 > 4 > 1 by station. Comparison of stations using ANOVA revealed a significant difference (P < 0.05) between the upstream and the slope stations.

A total number of 338 specimens of Macrobrachium vollenhovenii were bought from fisher folks who fished from Ubeji, Jala and Soroghagbene; but marketed their landings at Ubeji. Specimens were collected at monthly intervals between March and November, 2011. The male to female sex ratio established was 1:2:3. The size at first maturity was 9.0 cm for males and 10.0 cm for females. The length-weight relationship revealed an increase in total length of each specimen as body weight increased. The regression coefficient 'r' was significant at p< 0.05 for male (0.901) and female (0.644) specimens. An average condition factor of 3.9 and 2.74 was recorded for males and females respectively. The Gonado-Somatic-Index (GSI) was generally higher, especially during the month of July for females (0.60) than for males (0.50). Distinct histological changes were observed in the gonads of both sexes. Gonad development revealed five distinct stages (dominant, developing, developed, ripe and spent) for both sexes. Fecundity ranged between 5,540-28,470 eggs, and was highly correlated with total length (0.979) but not with body weight (0.185). Fecundity was highest in the month of July (20,113) and lowest in the month of August (6,140). It could be concluded that matured specimens probably spawn, in March and in July, when GSI were at their peaks. This pattern of breeding suggests that they were capable of multiple spawning within a single reproductive season.

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The present study aims to evaluate the potential ecological risk (PERI), pollution load index (PLI) and Geo-Accumulation Index (Igeo) of soil pollution by heavy metal around the solid waste dumpsites in Warri and Environs. The concentrations of Pb, Cu, Ni, Cr Zn, Cd, Fe and Mn were monitored using atomic absorption spectrophotometer (Unican 929) for 12 months in the selected dumpsites. The spatial variation of Pb, Ni, Cr and Zn showed no significant difference across the sampling location when subjected to one-way ANOVA while evaluation of PLI reviled a value of less than one in all the sample location which indicates no pollution. PERI was evaluated with a value of ER < 30 across the sampling locations which indicates slight pollution and Igeo result showed that the soil at all the study areas are practically uncontaminated by heavy metal. The concentrations of heavy metals in the soil within the vicinities of the dumpsites were within the DPR (2002) stipulated levels. These findings suggested some managerial strategies to avoid escalation of soil contamination by heavy metal at the selected dumpsite and other similar areas elsewhere.