The rising cost and limited availability of conventional feed ingredients such as fishmeal pose a significant challenge to sustainable aquaculture, especially in developing countries. This study investigated the potential of water hyacinth (Eichhornia crassipes), an invasive aquatic plant, as a costeffective alternative in fish diet formulations. Five experimental diets were formulated by progressively replacing fishmeal with water hyacinth leaf meal at 0%, 25%, 50%, 75%, and 100% inclusion levels, respectively. Proximate analyses were conducted to determine moisture, ash, crude protein, crude fibre, lipid, and carbohydrate contents using standard AOAC methods. Results showed that water hyacinth inclusion significantly influenced the nutritional profile of the diets. Diets with higher water hyacinth content exhibited increased ash and crude fibre levels, indicating a rich mineral composition and high fibre potential. However, crude protein content decreased with higher inclusion levels of water hyacinth, with the highest protein value recorded in the fishmeal-based diet. Lipid levels were generally low across all treatments, particularly in diets with high water hyacinth proportions. Carbohydrate content remained moderately stable across all formulations, with a slight increase in the highest inclusion level. The study concludes that water hyacinth possesses promising nutritional attributes that could complement traditional fishmeal, particularly as a mineral and fibre source. However, its low protein and lipid contents may limit its use as a sole feed ingredient. Therefore, its optimal application lies in partial replacement strategies that balance nutritional adequacy with cost-effectiveness. This work highlights the potential for converting an ecological burden into a valuable input in sustainable aquaculture feed development.
Water determines the success or failure of an aquaculture operation to a greater extent. During dry season and regions with low accessibility to water, productivity tends to be reduced. This study determined the effect of different levels of water exchange required for producing African mud catfish. One hundred and eighty Clarias gariepinus (2.69±0.94 g fish-1 ) were randomly distributed at 15 fish per tank into four treatments with three replicates. Each treatment was named according to the daily water level renewal, namely; T0 (Complete renewal), T1 (Quarter renewal), T2 (Half renewal) and lastly, T3 (three-quarters renewal). The experiment lasted eight weeks, twice daily feeding with commercial feed at 5% body weight. No significant differences recorded in the water quality parameters of all the treatments. However, T2 had the highest final weight of 52.06±1.01g and weight gained 6.73±3.96 g. T2 retained the highest specific growth rate (6.01±1.42 g day-1 ). The most increased FCR was recorded in T0 (0.64±0.30). All the treatments had high survival at the end of the experiment, with the highest value (90-100 %). The result showed that PCV and haemoglobin were significantly (P<0.05) higher in T2 (31.00±0.0 % and 10.30±0.0 g/dl) and T1 (31.00±1.41 % and 10.50±0.7 g/dl). Red blood cell was significantly higher in T0 (2.15±0.07). This study showed that the daily water exchange to half the water level volume produced the best result in terms of growth performance. This is optimum and affordable for growth and health of Clarias gariepinus fingerlings production.
Macrophytes play a vital role in aquatic ecosystems, serving as indicators of environmental health and influencing nutrient cycling. Kandola Shella Stream of Usmanu Danfodiyo University, Sokoto is a unique ecosystem for studying these relationships in a semi-arid region. This study aimed to evaluate macrophyte diversity in relation to sediment composition within the Kandola Shella Stream. The stream was divided into three locations (A, B, and C) for the study. Field surveys and standard laboratory procedures were conducted to identify macrophytes species and examine sediment physicochemical properties. A total of 17 Macrophytes species from 11 families were identified. Emergent species dominated the stream, accounting for 53% of all observed species. At location A, Pistia stratiotes was most abundant, while Nymphaea lotus and Panicum hemitomen dominated at location B. At location C, Azolla pinnata was the predominant species. Sediment analysis revealed slightly acidic conditions across all sections, with pH values ranging from 6.53 to 6.62. Electrical conductivity (EC) was highest at location A, reflecting potential variations in ion concentrations. Nutrient analysis showed fluctuations in nitrogen, phosphorus, and potassium levels across the sections. Heavy metal concentrations revealed consistent cadmium levels, with elevated copper and lead concentrations observed at location A. Macrophyte distribution in Kandola Shella Stream was strongly influenced by sediment composition, emphasizing the role of sediment in shaping aquatic vegetation and this type of study will support ecosystem management and conservation efforts.
The quality of water in the Ethiope River was assessed across three stations to evaluate the impacts of flooding and anthropogenic pollution. Physico-chemical parameters including pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), electrical conductivity (EC), total dissolved solids (TDS), nitrate, phosphate, and heavy metals were measured. Station 1, located upstream, exhibited minimal contamination, with water quality parameters largely within WHO (2011) guidelines, reflecting a relatively pristine environment. In contrast, Station 2, situated at the flood discharge point, showed significant pollution, marked by elevated BOD, nitrate, phosphate, and EC, indicative of contamination from agricultural runoff and urban wastewater. The Water Quality Index (WQI) at Station 2 was the highest, highlighting severe water quality degradation. Station 3, downstream, displayed partial recovery, with improved BOD and EC levels, although phosphate and nitrate concentrations remained elevated. The seasonal variation in water quality was significant (P<0.05), with wetter conditions exacerbating nutrient loading and organic matter input, while the dry season showed some attenuation. These findings suggest that the Ethiope River is subjected to both natural and anthropogenic stressors, with flood events intensifying pollution levels, especially at Station 2. The river’s ability to self-purify downstream was evident, though continuous pollution sources upstream led to ongoing contamination. This study contributes to understanding the impact of flooding and pollution on water quality in tropical rivers, providing insights into the resilience and challenges faced by river ecosystems in flood-prone regions.
This study assessed the temporal variations in water quality parameters in six earthen ponds in Effurun, Delta State, Nigeria, over six months, focusing on aquaculture suitability. pH remained stable (6.47–6.87) within NESREA standards (P > 0.05). Electrical conductivity (455.13 ± 207.11 µS/cm) and total dissolved solids (264.50 ± 102.20 mg/l) were below regulatory limits but increased significantly by June due to seasonal effects (P < 0.05). Turbidity (108.19 ± 44.09 NTU) and Total suspended solids (80.71 ± 44.40 mg/l) exceeded NESREA limits, peaking in April and February, likely due to sediment resuspension (P < 0.05). Potassium (0.67 ± 0.20 mg/l) and Alkalinity (20.42 ± 8.97 mg/l) showed moderate variations (P > 0.05), while Salinity (0.21 ± 0.08 g/L) and Sulfate (67.01 ± 13.84 mg/l) remained within acceptable limits (P > 0.05). Dissolved oxygen (6.14 ± 1.06 mg/l) met aquaculture requirements, and Biochemical oxygen demand (3.53 ± 1.07 mg/l) indicated low organic pollution (P > 0.05).Heavy metal concentrations exhibited no significant seasonal variations (P > 0.05). Iron ranged from 10.23 to 10.71 mg/l, Arsenic remained at 0.03 mg/l, and Cadmium varied slightly (0.32–0.33 mg/l). Nickel and vanadium were undetectable, while Barium (0.07 mg/l), Cobalt (0.02 mg/l), Chromium (0.11 mg/l), and Manganese (0.07 mg/l) showed minimal fluctuations. Zinc declined from 0.13 mg/l in January to 0.09 mg/l in March before stabilizing. Lead (0.03 mg/l) and Selenium (0.05–0.06 mg/l) remained stable.These findings highlight seasonal influences on some parameters but overall stability in heavy metal concentrations, underscoring the need for continuous monitoring to support sustainable aquaculture.
Z-germicide, a phenolic disinfectant released into aquatic environments through industrial, agricultural, and domestic effluents, poses significant ecological risks. Although its toxicity to vertebrates is relatively well studied, little is known about its effects on aquatic insects that perform vital ecological functions. This study investigated the acute toxicity of Z-germicide on the whirligig beetle Orectogyrus bedeli Regimbart, 1884, by determining median lethal concentrations (LC₅₀) over different exposure periods. Laboratory bioassays were conducted at 20–22 °C, where beetles were exposed to graded concentrations of Z-germicide. Mortality was recorded at 24, 48, 72, and 96 hours, and LC₅₀ values were calculated using probit analysis. Water quality parameters, including dissolved oxygen, pH, conductivity, and total dissolved solids, were also measured. Results showed declining LC₅₀ values with increasing exposure time: 47.846 mg/L at 24 hours, 36.7891 mg/L at 48 hours, 8.670 mg/L at 72 hours, and 7.769 mg/L at 96 hours. Mortality followed a clear concentration and time-dependent trend. Conductivity and total dissolved solids increased significantly, while dissolved oxygen and pH remained relatively stable. These findings demonstrate the acute toxicity of Z-germicide to O. bedeli and highlight the ecological risks posed by phenolic pollutants. Effective pollution control and wastewater management are essential to protect aquatic biodiversity.
Water is the most vital natural resource, sustaining all life forms. Any alteration in its quality can disrupt ecological balance and render it unsuitable for use. Prawns, positioned delicately in the aquatic food chain, can bioaccumulate heavy metals at levels that may pose health risks to consumers. This study evaluated the concentrations of heavy metals (Fe, Zn, Cu, Pb, Cd, and Cr) in the prawns, Macrobrachium macrobrachion and M. vollenhovenii, and the physicochemical characteristics of water from the Benin River. Samples were collected monthly from four stations between October 2018 and May 2019. Physicochemical parameters, including temperature, pH, electrical conductivity (EC), salinity, turbidity, total suspended solids (TSS), total dissolved solids (TDS), dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), and major ions were determined using standard methods, while heavy metals were analyzed by atomic absorption spectrophotometry. Data were processed using descriptive statistics, unpaired t-tests, and ANOVA (SPSS). Most parameters were within WHO/FMEnv limits, except EC, chloride, TDS, Fe, Pb, and Cd. Apart from pH and vanadium, seasonal variations were not significant (P > 0.05). Heavy metals in prawns were within permissible limits, with no significant seasonal differences. Estimated Daily Intake (EDI) values were below regulatory thresholds, while Target Hazard Quotient (THQ) values were < 1, indicating negligible non-carcinogenic risks. The Hazard Index (HI) also remained < 1 throughout the study. These findings suggest that prawns from the Benin River are currently safe for consumption, though increasing anthropogenic pressures could elevate future risks. Given their nutritional and economic importance, routine monitoring of prawns and aquatic systems is recommended to safeguard public health and ensure sustainable resource use.
Surface water degradation is increasingly becoming a national issue in Nigeria as it affects the suitability of water for its various uses. The preliminary study of the physicochemical parameters and water quality index of the Orogodo River was conducted to ascertain the extent of degradation from multiple sources of contamination. Water samples were collected from four sites that were impacted by various anthropogenic activities along the Orogodo River in Delta State during the months of February (number of samples = 16) and September (number of samples = 16) 2020. The water samples were analyzed using standard methods. The results of the physicochemical analysis using ANOVA showed significant differences (P<0.05) only in biochemical oxygen demand and turbidity across the four sites. The biochemical oxygen demand (3.05±2.47) and turbidity (8.35±5.162) at site 3 espectively that is a major abattoir discharge point were above the Nigeria Standard for Drinking Water Quality acceptable limits for drinking water and could portend harm to water users and ecosystem integrity. The water quality index analysis revealed that sites 1 and 4 showed good water quality and those of sites 2 and 3 showed poor water quality. The study demonstrated that water quality index analysis and physicochemical characteristics were critical factors in evaluating the deteriorating conditions of the Orogodo River. Periodic monitoring of the river quality and integrity is vital as the river water will require extensive treatment for safe usage.
Elechi Creek of the Upper Bonny Estuary, Port Harcourt, Nigeria and its resources are economically significant. Still, the Creek is a sink receiving various anthropogenic effluents from its surroundings. The study determined the epixylon assemblage and some physico-chemical parameters [temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), dissolved oxygen (DO), biological oxygen demand (BOD), phosphate, sulphate, and nitrate] of the Creek. Surface water and epixylon sample collections from three stations followed standard methods between August and November 2021. Epixylon samples were analyzed microscopically. A total number of 461 individuals, 30 genera and 37 species from 6 families, namely: Bacillariophyceae (18 species), Chlorophyceae (9 species), Cyanophyceae (5 species), Chrysophyceae (1 species), Dinophyceae (3 species), Euglenophyceae (1 species) of epixylic algae were recorded. Pollution- indicator genera were Cyclotella, Nitzschia, Synedra, Cocconeis, Tabellaria, Melosira (Bacillariophycea) Ankistrodesmus, Chlorella, Closterium (Chlorophyceae), Oscillatoria and Phormidium (Cyanophyceae). Spatially, sulphate (137.02±25.00 mg/L) exceeded the NESREA standard (100 mg/L, respectively), while temperature (30.00±1.72 ℃), pH (6.70±0.79), TDS (2308.92±858.14 mg/L), DO (6.56±0.78), BOD (1.78±0.71 mg/L), nitrate (0.92±0.18 mg/L) and phosphate (0.25±0.06 mg/L) were within NESREA standard (<40 ℃, 6-9, 2000 mg/L, 6.0 mg/L, 3.0 mg/L, 9.1 mg/L and 3.5 mg/L, respectively). EC (4959.50±1836.34 µs/cm) exceeded the WHO standard (900 µs/cm). The presence of dominant Bacillariophyceae, some bioindicator species, and higher EC and sulphate denotes organic pollution in Elechi Creek. The study recommends thus periodic monitoring of Elechi creek and environmental awareness programmes to mitigate pollution and safeguard the health of the residents around this Creek.
Microplastic pollution has been considered an issue of considerable concern for society and aquatic ecosystems due to plastics' unlimited applications and admirable properties. This review paper investigated various groups and sources of microplastics, their potential impacts on aquatic biodiversity, and the mitigation and treatment measures. Microplastics were grouped according to their sources as primary and secondary microplastics. Primary microplastics are generated more from land-based activities (98%) than sea-based activities (2%). Sources of primary microplastics are personal care products, industrial scrubbers, plastic powders, and microbeads, among others. While sources of secondary microplastics are losses of plastic materials during natural disasters, material lost or discarded from fishing vessels and aquaculture facilities, and oil and gas platforms, among others. Microplastics cause toxic effects, reduced food intake, delayed growth, oxidative damage, abnormal behaviour, a barrier to lipid metabolism, and affect fishes at molecular levels, causing genetic damage whereby microplastics absorb polycyclic aromatic hydrocarbons, which cause immunotoxicity, neurotoxicity and genotoxicity to marine species. Mitigation measures to reduce the microplastic pollution's effects include the removal of microbeads from personal care products, improved reuse, recycling and recovery of plastics, improved separation efficiency at wastewater treatment points and development of clean-up and bioremediation and phytoremediation techniques. Treatment methods include microfiltration, ultra-filtration, nanofiltration and reverse osmosis. Microplastics have varying effects on aquatic organisms, but these impacts can be mitigated and treated with different techniques and policy instruments. Therefore, the study recommends avoiding disposing of, reusing, recycling and recovering plastic substances in the aquatic environment for safe and clean waters.
This study was conducted to assess the effects of ovaprim and pituitary extract on the reproductive performances of Heterobranchus longifilis (African catfish). A total of twenty broodstock, 12 males and 8 females with mean weight of 2 kg each were selected for breeding following the external morphological characteristics and standard breeding procedure. The water parameters for indoor culture tanks during the study were optimal for breeding: dissolved oxygen – 5.18 mg L-1 ; pH 7.31; temperature, 27.6 ˚C. The result revealed no significant (P > 0.05) differences in water quality parameters between the culture tanks for artificial and natural hormonal applications in this study. The percentage fertilization, hatchability, survival and fry production success were: 84.25 %, 92. 31 %, 88.14 % and 68.42 %; and 75.17 %, 69.57 %, 64.33 % and 33.66 %, respectively, for pituitary extract and Ovaprim®. Pituitary extract recorded higher values and significantly performed better (P < 0.05) between the two treatments. This indicates that the use of natural pituitary extract is equally as effective as the use of the artificial hormone Ovaprim® for the artificial propagation of Heterobranchus longifilis. It is therefore recommended.
The unregulated release of nano-particles into the environment induces toxicity in living organisms by interfering with normal cell processes. This study investigated the toxicity effects of both lethal and sub-lethal concentrations of ZnO-NPs on biochemical enzymes in the tissues of African catfish, Heterobranchus longifilis, by exposing to lethal concentrations (0.00, 60.00, 80.00, 100.00 and 120 mg/l) and sub-lethal concentrations (0.00, 6.00, 8.00, 10.00 and 12.00 mg/l) of ZnO-NPs for 96 h and 45 d in static renewal bioassays with continuous aeration respectively. After the exposure periods, blood was collected through the caudal fin of the fish from control and exposure groups and sacrificed to remove the gills and liver for biochemical assay. The results revealed a significant (P<0.05) increase in the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), acetyl cholinesterase (AChE), and the levels of total protein and glucose also increased significantly (P<0.05) in the blood, gills and liver with increase in the concentrations and exposure periods compared to the control. The alterations in the biochemical enzymes of the fish indicated that the release of ZnO-NPs into aquatic environment could be dangerous and may cause health risk in man through food chain.
The indiscriminate discharges of anthropogenic effluents containing heavy metals from the surrounding residential buildings and industries into Woji Creek are alarming and of environmental concern. This research thus aimed to compare the bioconcentrations of Lead (Pb), Cadmium (Cd) and Chromium (Cr) in the water and mudskippers (Periophthalmus barbarus) of Woji Creek to ascertain their suitability for human consumption. Samples of water and mudskippers were analyzed for these heavy metals using Atomic Absorption Spectrophotometer between October 2019 and September 2020. Water and P. barbarus samples were collected from three locations and transported to the laboratory for heavy metals analyses. The results showed that Pb, Cd and Cr concentrations (mg/L) in water were 0.741±0.550, 0.80±0.034 and 2.867 respectively, while that of fish (mg/Kg) were 3.554±0.91, 2.083±0.91 and 4.987±0.60 respectively. All the heavy metal concentrations studied exceeded the permissible limits of FMEnv and WHO. The hierarchy of heavy metal concentrations in both water and fish was Cr>Pb>Cd. All the metals studied exhibited significant (P<0.05) higher values in water in the dry season than wet season except Cr, while in fish, all were higher in the wet season than in the dry season except Pb. The bioconcentration factor showed that P. barbarus has a high potential to concentrate heavy metals in their body. The study showed that Woji Creek is under stress, and its P. barbarus is heavy metal-contaminated and unsuitable for human consumption. The study, therefore, recommends that there should be proper biomonitoring to avoid indiscriminate anthropogenic activities in the area.
Organosomatic and Haematological Indices are commonly reported in fisheries studies because they are easily determined and can be excellent predictors of adverse health in fish. The objective of the present study was to evaluate the toxicity effect of an organophosphate (dimethoate 40% EC) on catfish (Clarias gariepinus) juvenile using majorly two indices Hepatosomatic Index (HSI) and Haematological parameters. The fishes were exposed to three sub lethal concentrations 0.01 mg/l, 0.15 mg/l and 0.29 mg/l and monitored for 28 days. Result showed a significant decrease in the Hepatosomatic Index (HSI) of the treated groups when compared with the control recording 2.36g, 2.49g and 2.47g for 0.29mg/l, 0.15mg/l and 0.01mg/l respectively. Catfish (Clarias gariepinus) exhibited alteration which was significant (P<0.05) in the total white blood cell count amongst other checked parameters such as Red Blood Cell Count, Packed Cell Volume and Haemoglobin. Result of the study indicates potential toxicity of Dimethoate to juveniles of Clarias gariepinus for which aquatic environment must be continuously monitored.
The influence of anthropogenicity on the abundance and diversity of macro-invertebrates was investigated in Calabar River, Okomita, Cross River State for a period of 24 months (August, 2014-September, 2016) in six sampling stations. Bank root macro-invertebrates were collected by kick sampling while substrata macro-invertebrate samples were collected with a van-Veen grab. Seasonal variations in the values of the macro-invertebrates abundance were determined by pooling together the values for the wet and dry seasons. The difference in values in the six stations in each season was tested for significant difference (p < 0.05) while the pooled differences in the two seasons were tested using unpaired (independent) student’s t-test. Spcies diversity was estimated using the Shannon-Wiener index (H’), species richness (d) and evenness (J) of individual distribution among species. All macro-invertebrate groups had highest percentage abundance in the dry season months. Seasonal percentage abundance of insects was significantly different (p˂0.05). Higher seasonal abundance of the total macro-invertebrates was recorded in the dry season and the seasonal variation was significant (p˂0.05). Lower number of pollution intolerant species of macro-invertebrates (Sudanonautes africanus, Orectochilus orbisonorum, Dineutus discolour, Phaon iridipennis, Pila ovata, Natica flammulata and Eulima fischeri) recorded during the rainy season was an indication that the river was more perturbed during the rainy season as a result of influx of pollutants from refuse dumps, farmlands, Okomita Market, abattoir and mechanic workshop. The results of the PCA revealed that DO, hardness, alkalinity, magnesium and cadmium were the most important parameters influencing the abundance of macro-invertebrates in Calabar River, Okomita. Intermediate values and values less than one of Shannon-Weiner diversity index were observed, indicating that Calabar River, Okomita is moving from moderately polluted state to severely polluted condition.
In this study, fish pond water was collected from the artificial pond in the Department of Fisheries, University of Benin, Benin City, Edo State. The pond water was analyzed for some physicochemical parameters such as: temperature (T), pH, electrical conductivity (EC), total dissolved solids (TDS), total suspended solids (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD), total Kjeldahl nitrogen (TN), total phosphorus (TP), turbidity (Turb), chemical oxygen demand (COD), hardness (Hard), alkalinity (Alk) and bacteria count (BC). Biological treatment by mechanical aeration and chemical treatment with calcium hydroxide were carried out on the pond water. The treated pond water was characterized to evaluate the effectiveness of the treatments. Results obtained revealed increase in pH and dissolved oxygen after treatment but decrease in other parameters. The biological and chemical treatments were effective in reducing the concentration of most of the parameters. The treated pond water can be reused for irrigation but must undergo recarbonation to reduce pH and increase alkalinity.
This research was carried out to evaluate the effective and efficient treatment of abattoir wastewater using calcium hydroxide coagulant. Samples were collected from an abattoir unit in Ikpoba-Okha Local Government Area, Benin City, Edo State. The raw samples were characterized to determine: Dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD), temperature (T), pH, electrical conductivity (EC), turbidity, total dissolved solids (TDS), total suspended solids (TSS), total alkalinity (Alk), chloride, total Kjeldhal nitrogen (TN), hardness, potassium, phosphorous and total bacteria count (TBC). Thereafter, the samples were treated with several doses of calcium hydroxide coagulant (2g, 4g, 6g, 8g, 10g, 12g, 14g, and 16g). Results obtained were used to determine the optimum coagulant dosage in a plot of percentage COD against masses of coagulants used. From the optimum dose obtained (12g Ca(OH)2), a batch treatment was carried out. The treated wastewater was further characterized to ascertain compositional changes. Result revealed increase in oxygen and substantial reduction in chemical oxygen demand, total nitrogen, phosphorus and turbidity. Biochemical oxygen demand and total solids were also reduced. The treated effluent could be discharged into the environment without fear of pollution and may be reused for agricultural purposes.
This research was carried out between January and July 2021 in Akoko South West Local Government Area of Ondo State, Nigeria. Three sites in each of the eight towns of the Local Government Area were visited and sampled to determine and evaluate the relationship between mosquito species and biotic factors in the mosquito breeding environment. At each site mosquito larvae were collected and flora and fauna at each site were identified. The flora identified included grasses, green Algae, Pride of Barbados and others, while the fauna identified included Damsel flies, Dragon flies, Tadpoles, Midges, Lizard. The Damsel flies, Dragon flies and Tadpoles dominate the fauna distribution chart while Green Algae has the highest percentage of the flora distribution chart followed by grasses and pride of Barbados with the least percentage. The correlation coefficient indicated a positive relationship between larva density and flora while larva density and fauna showed some negative relationship. Adequate understanding of vector ecology is needed to control mosquito particularly in deploying environmental modification around host settlements. This understanding will better serve over deployment of chemicals into such sites that may affect non-targeted organisms.
This study was conducted to investigate the quality of some drinking water supply sources in Four-Corners, Ikom Local Government Area, Cross River State, Nigeria using World Health Organization (WHO) recommended standards for drinking water. The supply sources (three springs, three boreholes and three different products of sachet water) were randomly selected for the study. The water samples were subjected to physico-chemical and bacteriological analyses. Temperature, pH and conductivity were determined using handheld meters at sampling sites while other parameters were determined in the laboratory. The bacteriological analysis was carried out through membrane filtration techniques. Results from the physico-chemical test showed that pH, conductivity, chromium, copper, nickel and zinc for all the water supply sources were compliant with WHO standard while temperature, total hardness, calcium, iron and magnesium were higher than WHO standard limits. Total dissolved solids and turbidity were not detected in all the water samples from the three different water supply sources. Faecal coliforms were found in all the water sources, which points to the fact that the three water sources were unsafe for human consumption. The findings of this study deduced that none of the water supply sources met the WHO standards for drinking. Considering the potential impacts of unsafe drinking water, recommendations to save the situation have been made.
Taxonomy and biodiversity is an important aspect of fish studies as it gives fish scientists information about the types of fish present, their name and classification based on discrete sets in a given locality. This study is on the taxonomy and bio-diversity of Cichlids collected from the Eniong River and the Lower Cross River in the Niger Delta, Nigeria between January and June 2020. A total of 358 cich-lids were collected from three sampling stations (the Eniong River, the confluence and the lower Cross River). Sampling was conducted with active and passive sampling techniques with the help of local fishermen using various fishing gears including beach net (10 – 15 m length, 2 –3.5 m height, mesh size of 0.5 – 5cm), fixed gill net (40 – 60 m long, mesh size 15 – 57 mm), cast net (2 – 5 m diameter, mesh size 15 – 20 mm) and local traps (made from raffia palm). The sampling du-ration with the fishing gear and methods were approximately the same. Gill nets and traps were set between 1600 h and 1800 h and fishes caught were removed from the gear between 0600 h and 0900 h the next day. Fish were identified using morphological and meristic traits. The species found and percentage abundance were; Coptodon zilli (5.9%), Coptodon dageti (31.2 %), Coptodon guineensis (16. 4%), Hemichromis elongatus (6.4 %), Hemichromis fasciatus (2.2%), Ore-ochromis niloticus (5.3%), Oreochromis aureus (0.8%), Sarotherodon melanotheron (3.6%), Sarotherodon galileus (0.8%), Sarotherodon macrocephala (1.95%), Chromidotilapia guntheri (10.3%), Pelmatolapia mariae (12.3%), Tylochromis sudanensis (1.7%) and the unidentified species(0.8%). There was higher abundance of cichlids in Eniong River (36%) than in the confluence (34%) and lower Cross River (30%). Simpson’s diversity index was 0.97 - 0.98 in the three stations. Shannon-Wiener’s index of diversity was 2.18 in Station 1, 1.76 and 1.68 in stations 2 and 3 respectively. Margalef index of diversity was 2.05 in station 1 and 1.66 and 1.71 in stations 2 and 3 respectively. Some species ap-peared to be specific in their habitat; O.niloticus, O.aureus, S. macrocephala were found in freshwater. S. galileus in the estuarine habitat while all other spe-cies were found in all the stations. A dichotomous key which will serve as a guide for fish scientist in the field was prepared using morphomeristic characters.
