Ologe Lagoon Research Articles

Effects of anthropogenic activities on the microbial community diversity of Ologe Lagoon sediment in Lagos State, Nigeria.

The impact of pollution on the Ologe Lagoon was assessed by comparing physicochemical properties, hydrocarbon concentrations and microbial community structures of the sediments obtained from distinct sites of the lagoon. The locations were the human activity site (OLHAS), industrial-contaminated sites (OLICS) and relatively undisturbed site (OLPS). The physicochemical properties, heavy metal concentrations and hydrocarbon profiles were determined using standard methods. The microbial community structures of the sediments were determined using shotgun next-generation sequencing (NGS), taxonomic profiling was performed using centrifuge and statistical analysis was done using statistical analysis for metagenomics profile (STAMP) and Microsoft Excel. The result showed acidic pH across all sampling points, while the nitrogen content at OLPS was low (7.44 ± 0.085mg/L) as compared with OLHAS (44.380 ± 0.962mg/L) and OLICS (59.485 ± 0.827mg/L). The levels of the cadmium, lead and nickel in the three sites were above the regulatory limits. The gas chromatography flame ionization detector (GC-FID) profile revealed hydrocarbon contaminations with nC14 tetradecane > alpha xylene > nC9 nonane > acenaphthylene more enriched at OLPS. Structurally, the sediments metagenomes consisted of 43 phyla,75 classes each, 165, 161, 166 orders, 986, 927 and 866 bacterial genera and 1476, 1129, 1327 species from OLHAS, OLICS and OLPS, respectively. The dominant phyla in the sediments were Proteobacteria, Firmicutes, Actinobacteria, and Chloroflexi. The principal component ordination (PCO) showed that OLPS microbial community had a total variance of 87.7% PCO1, setting it apart from OLHAS and OLICS. OLICS and OLHAS were separated by PCO2 accounting for 12.3% variation, and the most polluted site is the OLPS.

Source apportionment, ecological and health risk assessment of potentially toxic elements in water, sediment and blackchin tilapia {Sarotherodon melanotheron (Rüppell 1852)} from Lagos and Ologe Lagoons, Lagos State, Nigeria

BackgroundLagos and Ologe Lagoons are parts of the Lagos Lagoon Complex, which provide fish as an animal protein source to the locals. However, these fish species have a high propensity to accumulate pollutants including Potentially Toxic Elements (PTEs) from their environment. This potentially constitutes a health risk to fish consumers. Therefore, this study investigated concentrations of some PTEs (As, Cd, Cr, Cu, Fe, Pb, Ni, and Zn) in water, sediment, and fish (Sarotherodon melanotheron) from Lagos and Ologe Lagoons, the ecological and health risks associated with the consumption of the fish as well as the likely sources of the PTEs. MethodsWater, sediment, and fish (S. melanotheron) samples were collected monthly for ten months (June 2022 - March 2023) from three sites: Badore and Baiyeku in Lagos Lagoon and Ologe Lagoon. The concentration of PTEs was determined in the environmental matrices {water, sediment, and three organs (gill, muscle, liver)}. The range of values for method detection limits (MDL), limits of detection (LOD), limits of quantitation (LOQ), and recovery rates were 0.01 – 0.025 mg kg−1, 0.00002 – 0.002 mg L−1, 0.0001 – 0.0067 mg L−1 and 97.19±2.45 - 99.85±1.16% respectively. The ecological risk of PTE in water and sediment was assessed by various indices. Estimated dietary intake (EDI), health risk index (HRI), and target hazard quotient (THQ) were the human health risk assessment indices employed. The distribution and source of the PTEs were analyzed using the coefficient of variation, Pearson's correlation matrix, principal components analysis, and hierarchical cluster analysis. ResultsThe water and sediment quality assessment indices indicated that the water and sediment from the lagoons had low contamination with respect to the eight PTEs studied. EDI values were generally less than 1 except for Fe and Zn. THQ for all PTEs in the three sampling stations and across the different population groups was less than 1 except for Fe. PCA revealed two major sources of PTE pollution which are natural and anthropogenic. As, Cd, Cr, Cu, and Pb were probably due to anthropogenic inputs like agricultural operations and industrial activities while Fe, Ni, and Zn may have occurred due to lithological sources like rock weathering and volcanic events. ConclusionBased on the result of the study, the waters from the lagoons are still suitable for agricultural usage. The sediments are also largely uncontaminated with respect to the eight PTEs studied. The EDI and THQ show that consumption of S. melanotheron from the sites may not constitute any significant health risk to humans and the sources of the PTEs are lithologic and anthropogenic.

Assessments of the impacts of chemical and hydrocarbon pollution on Ologe Lagoon water and its prokaryotic community structure

Assessments of the impacts of chemical and hydrocarbon pollution on Ologe Lagoon water and its prokaryotic community structure

Degradation of crude oil by the microbial populations of Lagos and Ologe lagoon waters

Introduction: hydrocarbon contamination of surface waters as a result of anthropogenic activity poses threat to ecosystems and counter their beneficial uses. Some indigenous microbial communities have the potential to purify such waters unaided. Aims: To show the biodegradative potential of microbial communities in Lagos and Ologe Lagoons during minimal pollution with crude oil. Materials and Methods: The total heterotrophic bacteria and hydrocarbon utilising bacterial and fungal populations were estimated from Lagos and Ologe lagoon water samples contaminated with 1% crude oil over 42-day incubation period by plate count and vapour-phase transfer techniques. Residual hydrocarbons were determined by Gas chromatography. Results: The predominant bacterial genera identified from the lagoons include Enterobacter, Klebsiella and Proteus, while Escherichia, and Morganella. Aspergillus and Mucor were the predominant fungal genera in both waters. The hydrocarbon degradation rate in the Lagos Island microcosm was 65.391±0.370 mg/l/d, degradation rate constant 0.05±0.01 /d, half-life 9.559±0.093 /d and percentage degradation of 95.315 ± 0.134. Corresponding values in the Ologe water were 61.190± 8.542 mg/l/d, 8.725 ±0.389 /d, 0.055±0.003/d and 96.345±0.488 respectively. There was almost complete disappearance of the various fractions of the oil in the two samples. The microbial communities from both lagoons effectively utilised majority of the hydrocarbon fractions after 42 days where 66.890±1.075 and 100±000 were recorded for benzene, toluene had 100±000 percent degradation, anthracene 96.755±0.119 and 99.726±0.026, and pristane had 91.674±0.222 and 99.943±0.015 while phytane had 96.44±0.058 and 99.670±0.104 respectively. Conclusion: Efficient biodegradation of moderate contamination crude oil could be achieved by indigenous microbial flora present in Lagos and Ologe lagoon waters.

Elemental pollution status of different components of Ologe Lagoon, Lagos, Nigeria

Abstract This study evaluated the concentrations and distributions of nutrient and non-nutrient elements in water, sediment, mud, and vegetation of Ologe Lagoon, Lagos, Nigeria. Nutrient elements including Na, Ca, K, and Mg were found in high concentration values in the different components of the freshwater ecosystem. While the water had the least concentration of the elements, Trapa natans had the highest. Aluminium showed similar distribution patterns in the different components, except for T. natans. All the samples correlated significantly with water (p <0.05). Both the sediment and mud showed low potential ecological risk indexes of 5.3 and 5.92, respectively. Copper had the highest ecological risk with respect to single regulator indexes in the mud and sediment, notwithstanding its low concentration in the two components. Pollution indices suggested the low severity of non-nutrient elemental contamination of water, sediment, mud, and vegetation of Ologe Lagoon, and therefore, it is safe for human consumption, but not for agricultural irrigation. Pistia stratiotes and T. natans showed potentiality for use as photo-stabilisers and phytoremediators for some of the elements. The presence of radionuclides and rare earth elements in the components of Ologe Lagoon are instructive for specific policy initiatives to mitigate their effects on the population.

Environmental Impacts of Agbara Abattoir Waste on the Ecosystem of Ologe Lagoon, Nigeria

Aims: This research was conducted to investigate the effects of Agbara abattoir wastes dumped into the Ologe lagoon.
 Place and Duration of Study: The study was conducted at Ologe lagoon in Lagos, Nigeria from September 2019 - December 2019.
 Methodology: Water samples from the lagoon were collected monthly from three sites in the lagoon for four months. 30m before the entry site, the entry site of the abattoir wastes, and 30m after the entry site. After collection, the samples were analyzed for 13 parameters following the guidelines of the American Public Health Association (APHA).
 Results: The result showed that the conductivity ranged between 80.94 to 139.93 (µS/cm). The pH ranged between 7.84 to 9.23. The total dissolved solids ranged between 44.00 to 110.24(mg/l). The total suspended solids ranged between 20.12 to 70.82 (mg/l). The ammonia ranged from 0.01 to 0.04 (mg/l). The biological oxygen demand ranged from 50.72 to 107.41 (mg/l). The chemical oxygen demand ranged from 202.94 to 497.17 (mg/l). The chromium ranged from 0.04 to 0.06 (mg/l). The coliform level ranged from 33.62 to 82.50 (cfu/100ml). The Escherichia coli ranged from 1.20 to 3.30 (cfu/ml). The nitrate ranged from 2.74 to 4.55 (mg/l). The nitrite ranged from 0.22 to 0.69 (mg/l). The phosphate ranged from 6.89 to 11.33 (mg/l).
 Conclusion: This research showed that the ologe lagoon is polluted and unfit for human consumption and aquatic life. Therefore measures should be put in place to ensure proper disposal of the abattoir wastes in other to increase the quality of the lagoon.

Heavy metals concentrations in water, sediment, water hyacinth (Eichhornia crassipes) and Frillfin Goby (Bathygobius soporator, Cuvier and Valenciennes, 1837) from Ologe Lagoon, Southwest, Nigeria

The level of heavy metals in water, sediment, water hyacinth (Eichhornia crassipes) and frillfin goby (Bathygobius soporator) from Ologe Lagoon and its tributaries were monitored because of the importance of the water bodies to the socio-economic well-being of the rural population. Physico-chemical parameters and selected heavy metals (Fe, Zn, Cu, Pb and Cd) contents of water, sediment, E. crassipes and B. soporator from six sampling stations in Ologe Lagoon were measured monthly from February to November, 2015. The range of concentration of heavy metals in sediment are: Fe (454±112-2756±1213mg/kg), Zn (3.89±3.08-18.7±6.83mg/kg), Cu (7.68±5.65-36.8±16.9mg/kg), Pb (6.24±2.56-11.2±4.45mg/kg) and Cd (0.42±0.17-0.92±0.42mg/kg). Heavy metal concentration in E. crassipes were 68.5±16.5-987±86.8mg/kg, 13.2±6.40-162±46.2mg/kg, 0.56±0.25-6.54±1.45mg/kg, 5.06±2.41-12.2±4.71mg/kg and 0.28±0.22-1.21±0.49mg/kg for Fe, Zn, Cu, Pb and Cd respectively. The concentrations of heavy metals in the muscle of B. soporator in wet season were: Fe, 8.30±2.29 mg/kg; Zn, 0.78±0.28 mg/kg; Cu, 16.20±6.20 mg/kg; Pb, 2.21±0.33mg/kg; Cd, 0.16±0.05mg/kg while in dry season, they were: Fe, 27.19±7.28 mg/kg; Zn, 24.47±6.27 mg/kg; Cu, 0.18±0.16 mg/kg; Pb, 1.72±0.07mg/kg; Cd, 0.19±0.03mg/kg. Hardness and turbidity showed significant (p<0.05) spatial variation. Concentrations of Fe, Zn and Cu in sediment varied significantly (p<0.05) among the sampling sites but Pb and Cd did not. The heavy metal content of water hyacinth from the six sampling stations exhibited significant (p<0.05) spatial variation except Cd. The concentrations of Fe, Zn and Cu in B. soporator were significantly (p<0.05) affected by season but Pb and Cd were not. Although only Pb exceeded the FAO/WHO maximum permissible limits in the tissue of B. soporator, regular monitoring of Ologe Lagoon is advocated in order stern further deterioration of the ecosystem and to protect the rural population that depend on it for sustenance.

Multi-metric Ecosystem Health Assessment of Three Inland Water Bodies in South-west, Nigeria, with Varying Levels of Sand Mining Activities and Heavy Metal Pollution.

This study was conducted to determine the health status of three water bodies (Badagry Creek, Ologe Lagoon and River Owo) exposed to varying degrees of sand mining activities and industrial pollution. Water, sediment and fish samples were collected monthly from the three water bodies between April 2019 and March 2020. Standard methods were used for the analysis of physico-chemical parameters, fish diversity indices, length-weight relationship, condition factor, sediment pollution indices, ecotoxicology of heavy metals in sediment, potential ecological risks and health risk assessment of heavy metals. Positive matrix factorization (PMF) was used to identify and quantify metal source. Shannon's diversity index (H') and condition factor varied between 2.03-2.37 and 0.84-4.86 respectively. Enrichment factor had a range of 4.05×10-4-8.65×10-1, while geoaccumulation index varied from -12.14 to -0.38. The mean quotients using the probable effect level (m-PEL-Q) are 3.91×10-4, 4.77×10-4 and 7.87×10-4 for Ologe Lagoon, Badagry Creek and River Owo respectively. The trend was the same with mean quotients using effect range-median (m-ERM-Q). The estimated dietary intake ranged from 0.00 mg/kg/day in Pb from River Owo to 1.15 × 10-3 mg/kg/day in Fe still from River Owo. The range of values of the target hazard quotient of the metals in Badagry Creek, River Owo and Ologe Lagoon are 1.23×10-4-1.65×10-2, 0.00-1.64×10-2 and 5.76×10-5-1.65×10-2 respectively. PMF identified three sources of metal into the aquatic ecosystems: agricultural, industrial and geological inputs. The study showed that the three aquatic ecosystems are healthy but require regular monitoring to promptly detect sudden changes in their health status.

Evaluation of Water Quality and Heavy Metal Concentration across Two Connecting Tropical Lagoons in Lagos, Nigeria

Ologe and Badagry Lagoons are important tropical lagoons in Lagos, Nigeria. The water quality and heavy metal concentration were studied for a period of 2 years (Aug. 2016 to Jul. 2018) using standard methods. The least temperature obtained was 28.70±0.05 °C in Ologe Lagoon during the wet season and the maximum recorded was 29.41±0.08 in in Badagry Lagoon during the dry season. During the wet season (May- October) the temperature was steady and similar between the two connecting tropical lagoons. The salinity values vary at different stations in both Lagoon, 0.06 to 0.44 % in Ologe Lagoon and 0.08 to 0.28 % in Badagry Lagoon. Badagry Lagoon showed significant higher values in conductivity, total dissolved solid, chemical oxygen demand, biological oxygen demand, total suspended solid and total hardness across seasons. Heavy metal results showed that except for lead (0.25±0.10 mg/L), Ologe Lagoon had higher concentrations of all examined heavy metals (Zinc, copper, iron, chromium, lead, cadmium, manganese and cobalt) than Badagry Lagoon across season. Furthermore, cadmium, manganese and cobalt were not detected in Badagry Lagoon across season. The two studied connecting Lagoons especially Ologe Lagoon is exposed to dramatic deterioration in its water quality due to different wastes that discharge into the water body. These lagoons are clearly polluted by metals for various utilizations. As a result, the study suggests enforcing the controls on waste discharged into lagoons.

Occurrence of Acetaminophen, Amoxicillin, Diclofenac and Methylparaben in Lagos and Ologe Lagoons, Lagos, Nigeria

The occurrence of acetaminophen, amoxicillin, diclofenac and methylparaben in Lagos and Ologe Lagoons was investigated by random sampling of the water bodies during rainy and dry seasons. Samples analysis was carried out using high performance liquid chromatography. For the two seasons, the mean environmental concentrations of acetaminophen in Lagos and Ologe Lagoons were 0.075 μg/L and 1.233 μg/L respectively. The mean environmental concentration of amoxicillin in Lagos Lagoon was 0.008 μg/L while 0.003 μg/L was the mean value in Ologe Lagoon. Diclofenac occurrence in Lagos Lagoon had a mean value of 0.136 μg/L while 0.519 μg/L was recorded in Ologe Lagoon. The environmental concentration of methylparaben in Lagos Lagoon was 0.453 μg/L while its means concentration in Ologe Lagoon was 0.089 μg/L. From the results, the environmental concentrations of acetaminophen and diclofenac inOloge Lagoon were higher than their level of occurrence in Lagos Lagoon. However, the levels of occurrence of amoxicillin and methylparaben in Lagos Lagoon were higher than their environmental concentrations in Ologe Lagoon. Methylparaben was the most frequently detected in the water bodies with 87.5% detection frequency. This was followed by diclofenac with 75%. Also, 50% of the water samples analysed contained acetaminophen while amoxicillin had the least (37.5%) frequency of occurrence. The study established that there are active pharmaceuticals compounds and excipients present in the Nigerian aquatic environment which are micropollutants of emerging environmental concerns and of significant ecological risk. Therefore, there is need for environmental regulators to make concerted efforts towards environmental monitoring of this group of pollutants.Keywords: Acetaminophen, Amoxicillin, Diclofenac, Methylparaben, Environmental Occurrence

Seasonal and spatial variations in physico-chemical parameters of water and proximate composition of Macrobrachium macrobrachion from Ologe lagoon and Badagry creek, Lagos, Nigeria

In this study, seasonal and spatial variations in physicochemical parameters of water and proximate composition of Macrobrachium macrobrachion from Badagry Creek and Ologe Lagoon were examined. Samples of water and M. macrobrachion were collected from both stations on a monthly basis for six months. The physicochemical parameters monitored were pH, temperature, total suspended solids, total dissolved solids, total solids, total alkalinity, free carbondioxide, conductivity, salinity, dissolved oxygen, biochemical oxygen demand, ammonia and turbidity, while the proximate composition parameters were moisture content, crude protein, crude fibre, carbohydrate, crude lipids and ash. It was observed that alkalinity, salinity, dissolved oxygen, temperature and ammonia determined for both sample stations were within recommended limit of Food and Agricultural Organization, except pH for Badagry creek. There was no significant difference (p > 0.05) in seasonal variations of most physico-chemical parameters in both stations except for pH in Ologe lagoon, and electrical conductivity (EC), total dissolved solids (TDS) and total solids (TS) in both stations. Also, with the exception of EC, TDS and TS, there was no significant difference for spatial variation of physico-chemical parameters between the two stations. Moisture content, lipid and ash contents showed significant seasonal variation in Ologe lagoon, while crude protein and crude fibre recorded no significant difference. For Badagry creek, with the exception of moisture content, all other proximate composition parameters showed significant difference. However, there was no significant spatial variation in proximate composition between the prawns in Ologe lagoon and Badagry creek. There were gradual effects of season on water quality and proximate composition but these effects still support growth and survival of the prawn. However, regulatory measures should be put in place to protect these water bodies from direct/indirect human activities that can cause adverse damages.

Occurrence of a Polychlorinated Biphenyl (PCB) Congener in Surface Water, Sediments and Blackchin Tilapia (<i>Sarotherodon melanotheron</i>) from Ologe Lagoon, Nigeria

Polychlorinated biphenyls (PCBs) are persistent organochlorine chemicals that are toxic to aquatic organisms and humans. PCBs levels were assessed in surface water, sediments and fish from Ologe Lagoon, a major water body receiving treated effluents from Agbara Industrial Estate, using Gas Chromatograph-Electron Capture Detector (GCECD). 2,4,4’-Trichlorobiphenyl (2,4,4’-TCB) was the only PCB congener detected in the assessed matrices. Sediment 2,4,4’-TCB levels ranged from 0.0033±0.00333 to 0.0430 ± 0.00351ng/g. There was a significant (p < 0.05) seasonal variation in the levels in sediments and surface water. The level in surface water from Zone 3 was above USEPA’s safe limit (0.0005 mg/L) in the rainy season. There was no significant (p > 0.05) seasonal difference in the mean concentrations of 2,4,4’-TCB in fish, and the levels were lower than WHO’s safe limit (0.2 mg/kg). Based on the negligible to low levels of 2,4,4’-TCB in S. melanotheron inhabiting the lagoon, the fish was considered safe for consumption. Levels of 2,4,4’- TCB found in the sediments and surface water in this study indicate that levels may change with season, therefore, we recommend that the concentrations of the compound are regularly monitored in order to timely avert toxic levels of bioavailable 2,4,4’-TCB in the water body.Keywords: Polychlorinated biphenyls, Sarotherodon melanotheron, Sediments, Surface water.

Heavy Metal Concentrations in Chrysichthys nigrodigitatus (Lacepede, 1803) and Eichhornia crassipes (Mart) from Ologe Lagoon and its Tributaries in Lagos, Nigeria

Introduction: Heavy metal content of aquatic ecosystems is attracting global attention because of the ecological and human health risks associated with high levels of these metals in the environment. Aim: This study investigated the heavy metal content of various compartments of Ologe Lagoon in order to ascertain the safety of the consumption of fish and other resources from this water body. Materials and Methods: Samples were collected between June and November 2015, from the stations on monthly basis. Some physico-chemical parameters (alkalinity, salinity, pH, turbidity and hardness) and the levels of five heavy metals (Zn, Fe, Cu, Cd and Pb) in water, sediment, Eichhornia crassipes and a commercially important fish (Chrysichthys nigrodigitatus) were studied using standard procedures. Results: The ranges of values of the metals in sediment were: Fe (431.10±109.75-2560.33±1101.32 mgkg–1), Zn (3.77±2.55-17.29±5.30 mgkg–1), Cu (7.45±6.55-35.21±33.79mgkg–1), Pb (5.98±2.29-12.89±4.22 mgkg–1) and Cd (0.31±0.31-0.88±0.21 mgkg–1). The concentrations of heavy metals (except Cu) in Eichhornia crassipes have exceeded FEPA and WHO maximum permissible limits. The mean concentrations of heavy metals (except Zn) in Chrysichthys nigrodigitatus were above the limit recommended by FEPA and WHO. Conclusion: The study showed that the metal load in the biota of Ologe Lagoon is increasing and this may be harmful to inhabitance of the community, who depend on the services provided by this aquatic ecosystem. Therefore, efforts should be made by all users of the water bodies especially the industries to treat their wastes before discharging them into these aquatic ecosystems.

Polycyclic Aromatic Hydrocarbons in Ologe Lagoon and Effects of Benzo[b]fluoranthene in African Catfish.

Ologe Lagoon is an important water body that receives effluents from neighboring industries. These effluents may increase the levels of anthropogenic contaminants in the lagoon, thereby creating stressors for aquatic organisms. To assess the occurrence of polycyclic aromatic hydrocarbons (PAHs) in Ologe Lagoon, along with the histopathological, biochemical and genotoxic effects of the most prevalent PAH compound. An initial field study was performed to determine the concentrations of PAHs in Ologe Lagoon, followed by a chronic toxicity test to assess the effects of the most prevalent PAH compound in a fish model (Clarias gariepinus). High molecular weight PAHs were more predominant than low molecular weight PAHs in the lagoon, with B[b]F being the most predominant. The formation of micronuclei and binuclei was induced by a 10-fold increase over the present environmental concentration of B[b]F in Ologe Lagoon. Histopathological studies showed that epithelial necrosis, fused lamellae, shortened lamellae, and desquamation were the major histological anomalies induced by ERCs of B[b]F. Results from the biochemical assay indicated that ERCs of B[b] F increased aspartate aminotransferase and alanine transaminase levels in fish. Glutathione-S-transferase, superoxide dismutase and catalase were inhibited in the exposed fish, whereas malondialdehyde was significantly increased. Concentrations of fluoranthene, pyrene, benzo[a]anthracene, and benzo[a] pyrene in the surface water of Ologe Lagoon were above the Canadian Council of Ministers of the Environment's (CCME) safe limits, suggesting that the water may not be safe for domestic uses, and the present concentration of B[b]F in Ologe Lagoon may be chronically toxic to aquatic organisms, in terms of oxidative stress and hepatotoxicity. The authors declare no competing financial interests.

Assessment of Heavy Metals Pollution in Sediments from Ologe Lagoon, Agbara, Lagos, Nigeria

This study was carried out to assess the level of heavy metals pollution in Ologe Lagoon, Agbara, Lagos, Nigeria. The Lagoon receives effluents from industries in the Agbara Industrial Estate. Cored Soft sediments were retrieved from six random sampling points within the Lagoon and labeled (S1, S2, S3, S4, S5 and S6). Subsamples of the sediments were prepared and analyzed for heavy metal concentration. The result from the heavy metal analysis of the sediments shows that average concentration of Mn, Zn, Cr, Ni, Cr, Ni, Co, Cu and Pb in the samples was 278.1 ppm, 21.7 ppm, 14.2 ppm, 6.6 ppm, 6.4 ppm, 6.4 ppm and 4.4 ppm, respectively. The correlation between the heavy metals varies from 0.71 to 0.98 shows that they have a strongly positive degree of association which suggests that they are from the same source. The geo-accumulation values for Cu in all stations ranged between (1 - 2.8 ppm) and it can be deduced that the sediments are moderately to strongly polluted. Pb varies between 1 and 2.1 suggesting that the sediments are moderately polluted. Zn exhibits strong pollution levels with a range from 2.5 and 3.5 ppm. Co is moderately polluted with 1.5 - 2.4 while Mn shows the highest level of pollution in all stations with Igeo values ranging between 4.1 and 5.8. This study showed that the Lagoon accumulates heavy metals as a result of anthropogenic activities evident in the dumping of municipal, sewage, industrial waste in the environment and domestic activities such as auto mobile transportation and mechanic repair workshop. Based on sediment quality guidelines, the Ologe Lagoon level of pollution ranged from Cu > Pb > Zn > Ni > Co > Mn > Cr > Al with Mn having the highest level of pollution.

Levels, Spatial and Seasonal Distribution of Polybrominated Diphenyl Ethers (PBDEs) in Water, Sediments and Sarotherodon melanotheron from Ologe Lagoon

Levels, Spatial and Seasonal Distribution of Polybrominated Diphenyl Ethers (PBDEs) in Water, Sediments and Sarotherodon melanotheron from Ologe Lagoon

Total and Polyaromatic Hydrocarbons in Water, Sediment, Fin and Shellfishes from Badagry Creek and Ologe Lagoon, Lagos, Nigeria

The concentrations of eleven (11) polyaromatic hydrocarbons (PAHs) and total hydrocarbons (THC) were investigated in the water, sediment, Chrysichthys nigrodigitatus and Macrobrachium macrobrachion from Badagry Creek and Ologe Lagoon in Lagos, Nigeria using EPA and Gas Chromatography (GC) methods. All the samples(except water measured in mg/l) were measured in μg/g. PAHs were not significantly different(p>0.05)across the two stations and were within WHO recommended limit.The highest concentration of THC from Badagry Creek was recorded in M. macrobrachion (219.565±171.891 μg/g) and this value exceeded WHO recommended limit. Similarly, the highest THC (211.565±127.923 μg/g) recorded in M .macrobrachion at Ologe Lagoon was above WHO limit. The study has shown that the polyaromatic hydrocarbons were below the risk level, which indicated no risk status from the consumption of the fish species studied. However, C. nigrodigitatus and M. macrobrachion studied from these water bodies are highly contaminated with THC. Therefore, persistent monitoring and strict adherence to responsible waste discharge should be upheld by all industries near these waters in order to avoid deleterious effects on the biota as well as ensuring safety of the consumers.

Phytoplankton Composition and Dynamics at A Tropical Tidal Creek, Lagos.

The diversity and dynamics of phytoplankton at a tropical tidal creek in Lagos, in relation to water chemistry changes, were investigated for twenty-four months. Water samples were collected with a 75cl plastic bottle whereas phytoplankton samples were collected by a 55 µm mesh size standard plankton net towed horizontally for 5 mins at <4 Km/h. Water samples were processed to the laboratory for analysis and the phytoplankton samples were preserved by the addition of 4% unbuffered formalin. Water chemistry characteristics were measured using standard methods. The drop count microscopic analysis method was used to study the phytoplankton. Notable parameters that showed marked variations with season include salinity (0.17 – 30.4‰), rainfall (6 – 330mm), transparency (26 – 191cm), total suspended solids (30 - 360 mg/L), total hardness (18 - 3760 mg/L), chloride (60 - 11165 mg/L), conductivity (263 - 32900 µS/cm), total dissolved solids (197 - 21230 mg/L), sulphate (18.9 - 1140 mg/L), nitrate (4.1 - 42 mg/L), calcium (4.9 – 400.2 mg/L), Magnesium (1.4 - 648 mg/L) and iron (0.08 – 0.99 mg/L). A total of sixty-four phytoplankton species (dominated by diatoms) from five (5) algal classes namely Bacillariophyceae (43 species), Cyanophyceae (11 species), Chlorophyceae (7 species), Euglenophyceae (2 species) and Chrysophyceae (1 species) were observed. The green algae, euglenoids and golden brown algae were more frequently occurring during the wet season. The species with the highest biomass (in terms of numbers) was Aulacoseira granulata var. augustissima. The preponderance of very few species primarily Aulocoseira and Microcystis species in the wet season and Coscinodiscus, Actinoptycus, Odontella and Parabelius species in the dry season is a reflection of the changing water conditions within the tidal creek system from season to season and from fresh to high brackish water conditions. Freshwater taxa in the lagoon were primarily recruited from the freshwater areas especially upstream and including the Ologe lagoon from where they existed in higher concentration and usually brought in with floodwater inflow during the rains. Species of Surirella where likely scoured from the creek substratum whereas Parabelius (tube diatoms) were detached from attached submerged hard substrates

Haematological and Hepatic Responses of the African Catfish Clarias gariepinus to Sublethal Exposure of Industrial Effluents from Ologe Lagoon Environs, Lagos, Nigeria

Haematological and Hepatic Responses of the African Catfish Clarias gariepinus to Sublethal Exposure of Industrial Effluents from Ologe Lagoon Environs, Lagos, Nigeria

Seasonal variation of fish species and genotoxic effects as a result of human activities at the Ologe Lagoon, Nigeria

The fish abundance was determined by monitoring and recording the fish-catch data at the Otto Jetty in the Ologe lagoon. The diversity indices used for the purpose of this project were Species richness (S) and Shannon – Weiner index (H´). Three fish species from the lagoon were used for the micronucleus assay and nuclear aberrations; these are Tilapia guineensis, Sarotherodon melanoteron , and Chrysichthys nigrodigitatus. Diversity indices (H) obtained for the months of June, July, August and September were 2.61, 2.54, 2.54, 2.61 respectively while evenness (J) for the months were 0.64, 0.60, 0.53, 0.44 respectively. Apart from the presence of micronucleus, the genotoxicity assay also showed the presence of binucleated nucleus and blebbed nucleus. These are evidence that Ologe lagoon has a certain level of pollution, though at a minimal level. As advanced by this research work, there is great variation in fish composition and abundance in Ologe lagoon in relation to changes in the physical and chemical state of the water in the lagoon during the months of this research and this is very crucial to the biological life of the lagoon. However, anthropogenic activities should be regulated so as to prevent the level of pollution from increasing beyond tolerable limits.