Zooplankton-based assessment of the trophic state of a tropical forest river in Nigeria

In this study, we explore the usefulness of zooplankton as a tool for assessing the trophic status of a Nigerian forest river. The river was sampled monthly and investigated for water physico-chemistry and zooplankton community structure using basic statistical measurement of diversity indices to characterize the zooplankton fauna. The trophic sta­tus of the river evaluated from its physico-chemical parameters indicates that the river is oligotrophic. The zooplankton composition was typical of a tropical freshwater river, with a total of 40 species, made up of 16 rotifers, 12 cladocerans, and 12 copepods and their developing stages in the following order of dominance: Rotifera > Cladocera > Cyclopoida > Calanoida. There were strong correlations between the lake's trophic status and its zooplankton communities. The zoo­plankton community was dominated by numerous species of rotifers and crustaceans, which are typical of oligotrophic to mesotrophic systems, such species including Conochilus dossuarius and Synchaeta longipes. However, the most dominant zooplankton species in West African freshwater ecosystems, viz., Keratella tropica, Keratella quadrata, Brachionus angularis, Trichocerca pusilla, Filinia longiseta, Pompholyx sulcata, and Proales sp., and others that are indicator species of high trophic levels, were not recorded in the river. The river is very clear and can be used for all manner of recreational activities

Comparative Analysis of Contaminability between Clarias gariepinus and Tilapia mariae

Water, Clarias gariepinus and Tilapia mariae samples were collected from four (4) stations across the length of the Osse River between the periods of April, 2013 to September, 2014. Heavy metals (Iron, manganese, nickel and lead) and total hydrocarbons in water and fish tissues (gills, intestine and muscles) were tested using Atomic Absorption Spectrophotometer (Varian Techron Spectr AA – 10 Model; serial number 902 1318) and Agilent 6890N Gas Chromatograph - Flame Ionization Detector instrument (Model 6890) respectively. Much higher concentrations of all the contaminants (except lead) were detected in the intestine of Clarias gariepinus than the intestine of Tilapia mariae. This can be attributed to the fact that Clarias gariepinus- a demersal fish (bottom feeder) as opposed to Tilapia mariae (pelagic fish), must have been exposed to considerably high concentrations of heavy metals and total hydrocarbons (THCs) in the bottom of the river through foraging. The sequence of heavy metals and total hydrocarbons was the same in both fish species: Fe > Mn > THC > Pb > Ni as against the sequence in water: Fe > THC > Mn > Pb > Ni. The trend of the heavy metals and total hydrocarbons among the analyzed matrices was: Clarias gariepinus > Tilapia mariae > water. Despite the health risks (mainly of iron and manganese) observed in both species, no ecological risk was observed in the aqueous phase. This can be attributed to the significant bioaccumulation factors which are functions of their thresholds of essentiality. Results showed that Clarias gariepinus posed a higher level of health risk than Tilapia mariae. Furthermore, given that manganese alone contaminated the muscle of T. mariae while iron and manganese were the contaminants in the muscle of C. gariepinus, it is safer to consume the T. mariae than the C. gariepinus; particularly during the dry season

Trace Metals in Water, Bottom Sediment, Shrimp and Dependent Human Blood in Ukwuani Local Government Area of Delta State, Nigeria

Trace metals (Fe, Mn, Zn, Cu, Pb, Cd and Cr) levels were investigated in the water, bottom sediment, shrimp (Macrobrachium vollenhovenii) of Okumeshi River using Atomic Absorption Spectrophotometer (ASS);and blood of individuals that feed on the shrimps using an Inductively Coupled Plasma Mass Spectrometer (ICP-MS).The descriptive statistics such as the mean, range and standard error were for significant differences in the heavy metals, nutrients and total hydrocarbons in water and sediment samples was done using ANOVA (P < 0.05). Duncan Multiple Range (DMR) test was used to identify the source of variance using SPSS version 19.1.The order of accumulation in the matrices studied was bottom sediment > shrimp > water > human blood. High level of zinc and copper in human blood can be attributed to their high concentrations in all environmental matrices. It can also be attributed to the high biological accumulation factors of the metals in the shrimp. Copper also has a high essentiality in the respiratory pigment haemocyanin of shrimps. These facts are buttressed by the significant correlations of copper and zinc concentrations in the shrimp with their concentrations in human blood. The observed insalubrity of the shrimps is a prognostic of chronic health hazards to the consumers; which is also a function of the predominant oil exploration activities. Copper had an uninterrupted transit into the blood of the consumers from the aqueous phase. While zinc showed some significant level of biomagnification. The study provided an early signal of likely impending catastrophe; necessitating a proactive regulation of trace metals released into the aquatic system through the prevalent anthropogenic activities; mainly oil exploration

Zooplankton Diversity, Dynamics and Correlation with Physicochemical Parameters at Ugbevwe Pond in Delta State, Nigeria

Zooplankton are microscopic floating animals, which drift in water and whose swimming power if any, serve mainly to keep them afloat. A field study was conducted to determine the spatial and temporal variation in the zooplankton composition, dynamics and diversity at Ugbevwe Pond, Oghara, Delta State. Zooplankton samples were collected from three stations from August, 2014 to May, 2015 covering the wet and dry seasons. Zooplankton species were sorted and identified using appropriate identification keys. A total of six species of copepod belonging to two subfamilies and a total of five species of Cladocera belonging to three families were encountered. The spatial distribution of species of cladoera shows that of the five species encountered, three species namely Alona eximia, Alona costata and Macrothrix sp. occurred in all three stations. Diaphanosoma sp was restricted to station 1 while Pleuroxus ematus was restricted to station 3. The spatial distribution of species of copepod shows that of the six species encountered, Thermocyclops neglectus, Tropocyclops prasinus, Microcyclops varicans Mesocyclops bodanicola and Eucyclops serrulatus occurred in all three stations while Cryptocyclops bicolor was absent in station 1. Zooplankton was more abundant in the rainy season than the dry season. The relationship between zooplankton and the investigated physicochemical parameters showed that all the zooplankton correlated positively with depth, lead and total&nbsp; hydrocarbon and negatively with colour, sodium, Calcium, Iron and Zinc

Dataset on community structure of macro invertebrate fauna in Ubogo river, Udu LGA, Delta State, Nigeria

The datasetscontainedinthisarticlearebasedonabaselinestudy on theselectedphysicochemicalparametersandmacro-benthic invertebrates’ community ofEgini,andUbogoRiversinDeltaState for aperiodofsixmonths:February-July,2010,withininsix stations sharedequallyamongthetworiversusingthethree communities they flow throughasguideandwatersamplescol- lected onmonthlybasisfromthesestations.Theobjectivesinclude determination ofthespatialvariationsandbackgroundcon- centrations oftheselectedphysicochemicalparameters,species composition andabundanceofthemacro-benthicinvertebrates. Sixteen physicochemicalparameterswereanalyzedinthewater. Air andwatertemperatureandcurrentvelocityweredetermined in-situ; therestphysicochemicalparametersweredetermined adopting standardmethods.Dustingmethodwasadoptedin sampling themacro-benthicinvertebrates

Assessment of some heavy metals and total hydrocarbons in Clarias gariepinus fish of Osse River, Edo State, Nigeria

The sequence of the heavy metals (Fe, Mn, Zn, Cu, Pb, Cd and Cr) and total hydrocarbons (THC) in the water and tissues (gills, intestine and muscle) of an abundant and economically significant fish (Clarias gariepinus) harvested from Osse River were investigated from April, 2014 to September, 2015. Water and fish samples were collected from 4(four) chosen stations and were analysed for the levels of heavy metals and total hydrocarbons. The ecological risk of the study area and health risk indices of the fishes were assessed. Generally, accumulation of heavy metals and total hydrocarbons in the fish was gills > intestine > muscles (anomalous sequence). The sequence may pose some threats to the health of the consumers. Iron, zinc, copper, cadmium and THC showed significant health risk indices in the fish despite their insignificant ecological risk indices. Further in-depth study on the actual levels of risks to consumers is recommended

Health risk indices and zooplankton‑based assessment of a tropical rainforest river contaminated with iron, lead, cadmium, and chromium

Oil exploration’s devastation on health and the environment may far outweigh its economic benefits. An oil spill occurred at Egbokodo River in Delta State, Nigeria, thereby polluting the land and water bodies. The study was therefore aimed at evaluating the impacts of iron, lead, cadmium, and chromium on the zooplankton community structure of Egbokodo River and the potential health risks. Zooplankton and surface water samples were collected to investigate the concentrations of trace metals and zooplankton abundance. The associated carcinogenic and non-carcinogenic effects of the metals in the water were analyzed. Trace metal concentrations in the surface water were determined using atomic absorption spectroscopy (Philips model PU 9100) and zooplankton samples were collected using a hydrobios plankton net (mesh size 25 μm). Total petroleum hydrocarbons (TPH) and oil and grease (OG) were determined using Agilent 7890B gas chromatography coupled to flame ionization detector (GC-FID) and volumetric analysis respectively. The trend of the abundance of zooplanktons cross the river was 18 individuals (Station A) < 100 individuals (Station B) < 155 individuals (Station C). Cyclopoida proved to be the most resilient to the impacts of the oil spill. On a taxa basis, the order of abundance among Calanoida, Cyclopoida, Cladoceran, and Harpacticoida was Station C > Station B > Station A, except in Amphipoda where Station B > Station C > Station A was observed. Iron and lead posed significant carcinogenic risks that are liable to be inflicted by the ingestion of the water. The cumulative non-carcinogenic health risk in the male was the only significant (> 1) among the age groups. Total petroleum hydrocarbons (TPH), oil and grease (OG), iron, and lead had notable impacts on the general abundance of zooplankton in the aquatic habitat. The dominance of the Cyclopoida in the river buttressed the impact of the oil spill which warrants a prompt remediation measure. The pollution had notable ecological impacts on the zooplankton community structure of the aquatic habitat. The adults in the nearby human populations are liable to elicit carcinogenic health challenges associated with lead and iron ingestion. The males are at risk of non-carcinogenic illnesses which are associated with the combined toxicity effects of all the metals. The study suggests that the pollution in Egbokodo River was validated by the dominance of the Cyclopoida in the aquatic habitat. The study confers bioindicator reputation on the Cyclopoida for future biomonitoring studies

Interactions of trace metals with bacteria and fungi in selected agricultural soils of Egbema Kingdom, Warri North, Delta state, Nigeria

This study was aimed at investigating the relationship of trace metals with prevalence of bacteria and fungi in polluted farmland of Egbema Kingdom, Delta state. This may contribute to the knowledge on the influence of the microorganism to the arability of agricultural soil from an ecotoxicological viewpoint. Soil samples were analyzed for physico-chemical parameters and trace metals using atomic absorption spectrophotometer (Buck Scientific, 210VGP). The samples were also screened for fungi and bacteria isolates. Trace metals (Fe, Zn, Cd, Ni and Cu) determined in the agricultural soils of Egbema kingdom were below WHO limits. The fungi species with the highest number of occurrence was Aspergillus niger, while the species with the lowest occurrence were Fusarium oxsporium, Penicillium dirty white, and Penicillium sp. The order of abundance of fungi across the stations was Station 2> Station 4> Station 3> Station 1> Station 7> Station 5> Station 6> Station 9> Station 8. The bacteria species with the highest number of occurrence was Proteus sp I, while the species with the lowest occurrence was Alcaligenes sp. which occurred only once at Station 5. The order of abundance of bacteria in the soil samples across the stations was Station 4> Station 3> Stations 5 and 9> Station 2> Station 8> Station 7> Station 6. All trace metals in the agricultural soils of Egbema kingdom were below WHO limits. Fe, Zn, Cd and Ni showed no relationship with the microbial contents of the soil. Various strains of fungi and bacteria (gram positive and gram negative) were observed in the soil samples. An antagonistic relationship was observed between bacteria and fungi. Significant positive correlation occurred between the concentration of copper and bacteria counts indicating that the concentration of copper in the soil might have enhanced the abundance of bacteria in the soil, vice versa. The bacteria might be a promising tool in regulation of soil copper concentration

Principal Components and Hierarchical Cluster Analyses of Trace Metals and Total Hydrocarbons in Gills, Intestines and Muscles of Clarias gariepinus (Burchell, 1822)

The aim of the study was to comparatively analyze the interrelationships among iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr) and total hydrocarbons (THCs) in the gills, intestines and muscles of Clarias gariepinus collected from Osse River, Nigeria, between the periods of April, 2013 to September, 2014. The trace metals in the fish tissues were analyzed using Atomic Absorption Spectrophotometer (AAS, Philips model PU 9100), while total hydrocarbons were analyzed using High Performance Liquid Chromatograph (HPLC,Prominence Dual brand from HGE) equipped with a detector Shimadzu UV-Visible (UV-Vis Prominence SPD 20 A). The concentrations of trace metals and THCs in the tissues were subjected to principal component analysis (PCA), in conjunction with hierarchical cluster analysis (HCA), backed up by correlation analysis (CA). In the most prioritized component among the hierarchies of contaminants, characterized as principal component 1, results of communality extractions and rotated component matrices revealed the order of contaminants was Mn > Cu > Zn > Fe > Cr in the intestines, Cr > Cu > THCs > Mn > Fe in the muscle, while Pb > Cr > Fe > Mn was the order in the gills of the fish. Iron inhibited accumulation of the other trace metals in the gills, where its threshold of essentiality was maximal. Noteworthy is the fact that Mn and Cu were the most active components in the muscle and concurrently of excess concentrations in the tissue, which is the major edible part of fish, and constitutes its main body weight, hence holds its nutritional and economic values. High level of variability which occurred in the toxicant profile across the tissues of C. gariepinus is a function of uptake route, varied organ functions and specificity of tissue permeability of the compared organs. The study demonstrated variability in organ accumulation capacity and toxicant’s competitiveness irrespective of bioavailability. The study provides data useful for future ecotoxicological studies and safety of consumers of the fi