South-eastern Nigeria’s tropical water ecosystems typically consist of mangrove swamps and riparian forests, both of which have become endangered in the last six decades. The purpose of this research was to determine the extent of human-induced impact and activities on the effect of water quality on the distribution and diversity of benthic macroinvertebrates and fish fauna in the Tropical River (Ikang). The river’s surface water, benthic macroinvertebrates, and fish fauna were sampled and identified to create a database of reference information. Twelve (12) species of benthic macroinvertebrates from two (2) phyla were identified. Station 1 had the highest benthic macroinvertebrate abundance of 58 (35.65%), while Station 3 had the lowest abundance of 52 (31.70%). Uca tangeri was the most abundant benthic macroinvertebrate with a percentage abundance of 28 (17.07%), while Dinocras sp., Macromia sp., and Gomphus sp. were the least abundant benthic macroinvertebrates with a percentage abundance of 3.66%. In addition, seven (7) fish species from six (6) families were identified. During the study, the family Claroteidae was the most abundant, while the family Carangidae was the least abundant. The temperature of the river had a positive correlation with the families Carangidae and Mugilidae, a negative correlation with the family Clupeidae, and no correlation with the family Claroteidae. Total dissolved solids (TDS) correlated positively with the families Carangidae, Mugilidae, and Clariidae, while conductivity correlated positively only with the family Sciaenidae and negatively with the families Carangidae, Mugilidae and Clariidae. The abundance and diversity of benthic macroinvertebrates and fish fauna were generally influenced by the physical and chemical characteristics of the water, the availability of food, and the extent of human impacts and activities. In order to ensure sustainable water quality and biodiversity conservation in our environment, it is necessary to manage the river and the surrounding ecosystem appropriately.

In the present study, the water quality variables of the Idundu River were assessed by evaluating the Plankton community. Three sampling stations: Station 1 (minimal fishing), station 2 (artisanal fishing area/ cluster of human settlements) and station 3 (fisheries landing area, dredging) representing regions along the stretch of the watershed with considerable economic importance and anthropogenic activity, were selected within the period of six (6) months. The study determines plankton distribution, diversity and some water quality variables of Idundu River, and how they influence plankton abundance. The results of this study reveal that water quality variables (mean ± SD) of the River were pH (6.526 ± 0.104), surface water temperature (26.224 ± 0.106˚C), dissolved oxygen (1.474 ± 0.135 mg/l), nitrate (0.026 ± 0.001 mg/l) and phosphate (0.015 ± 0.000 mg/l). All the water quality variables assessed were within the acceptable range. A total of 23 phytoplankton species belonging to five families, totalling a numerical abundance of 368 individuals/L were observed. Bacillariophyceae was the most abundant phytoplankton family (63.81%), followed by Chlorophyceae (17.41%), Dinophyceae (7.87%), Cryptophyceae (9.77%), and the least abundant was Zygnemophyceae accounting for (1.08%). A total of 20 zooplankton species belonging to five phyla, totalling a numerical abundance of 140 individuals/L were observed. Rotifera was the most abundant zooplankton phylum (35.69%), Arthropoda (30.62%), Ciliophora (17.79%) and Annelida (12.15%); the least abundant was Nemata (2.85%). Principal component analysis (PCA) for plankton organisms showed that phytoplankton were more homogenously distributed than zooplankton during the study period. Shannon Wiener and Margalef’s diversity index showed that the River is in a healthy condition and the equitability level was high across all the stations, indicating even plankton distribution.

Microbial biodegradation of engine oil contaminated soil in Calabar Metropolis was studied for a period of six (6) months (January to June, 2017). The soil samples collected were ice boxed and taken to the laboratory for microbial, total hydrocarbon, total organic carbon and other physicochemical parameters analysis. A total of thirteen (13) indigenous bacteria species were identified in the soil of the sites analyzed during the study, which includes; Staphylococcus spp., Pseudomonas aeruginosa, Bacillus spp., E. coli, Enterococcus feacalis, Shigella spp., Arthrobacter spp., Alcaligen spp., Acinobacter spp., Azotobacter spp., Aeromonas spp., Xanthomonas spp. and Clostridium spp. The most abundant bacteria in the contaminated site was Staphylococcus spp. (65%) while the least Andem et al.; ASRJ, 2(1): 1-12, 2019; Article no.ASRJ.47089 2 bacteria count in the contaminated site was Clostridium spp. (9%). Staphylococcus spp. was the most abundant indigenous bacterial species and also the most effective biodegradation bacteria. The identified indigenous bacteria utilized the hydrocarbons, multiplied rapidly and then degraded the total hydrocarbon and total organic carbon more in the contaminated site compared to the control site. Site one recorded the highest bacteria count (927) while the least bacteria counts were recorded in the control site (81). The bacteria species showed its degradation and bioremediation capabilities prompting the need for its use in cleaning crude oil contaminated sites, due to the fact that it is cheap and not environmentally harmful. Original Research Article

Background and Objective: The feeding habit as well as the condition factor of Chrysichthys nigrodigitatus from lower river Benue was studied between July 2015 and September 2015. Materials and Methods: The natural food of the fish in the Lower River Benue was studied from stomach contents of the fish. A total of 100 stomachs were randomly examined and analyzed using two methods; the frequency of occurrence and point methods. About 92 had food items while 8 were empty. Analysis of variance (ANOVA) was used to test for significant difference at 95% confidence limit in the food eaten by these species and also the degree of stomach fullness. Results: Food items encountered using frequency of occurrence method include fish parts (47.62%), seeds (40.49%), sand/mud (30.09%), detritus (30.95%), digested food (29.76%), insect parts (27.38%), mollusk (25.00%) and algae (22.62%). Conclusion: C. nigrodigitatus had a euryphagous food habits and based on condition factor the fish were in good health.