Bioaccumulation Of Heavy Metals In The Catfish Chrysicthys Nigrodigitatus From Taylor Creek, Southern Nigeria

The discharge of liquid effluents either untreated or with only primary treatment into Etelebou Creek, a tributary of Taylor Creek has led to the extensive contamination of Taylor Creek by heavy metals. The catfish species, C. nigrodigitatus and other environmental segments were collected from five sites along Taylor Creek, southern Nigeria, and some metals determined by flame atomic absorption spectrophotometry. The concentration levels of the metals in C. nigrodigitatus were higher than values reported in the literature for fresh fish and may lead to a higher risk and harmful effects. The bivariate regression models relating metals in C. nigrodigitatus and metals in the surface waters were significant (R2 ≥ 0.7134). The Log (bio-concentration factors or BCF) of Cr and Zn in C. nigrodigitatus were the highest, whereas Ni was the lowest. The ecological distribution of the log (BCF) values was, for all the heavy metals, moderately stable over the Creek. All log-transformed biomagnification factors (BMF) in the Creek were positive, which indicates that the metal concentration was higher in C. nigrodigitatus than in suspended particulate matter (SPM). The absolute log (BMF) values of heavy metals can therefore be ranked in order of decreasing magnitude: Fe (4.06) > Zn (2.87) > Mn (2.59) > Cr (1.95) > Pb (1.90) > Ni (1.82) > Cd (1.55). This sequence indicates that toxic metals such as Cd, Cr and Pb are undergoing significant bio-reduction from SPM to C. nigrodigitatus. The degree ofcorrelation between the metals was different in C. nigrodigitatus, which suggests that the sources of the metals, polluting Taylor Creek were diverse

Occurrence and Diagenetic Evolution of Perylene in the Sediments of Oginigba Creek, Southern Nigeria

Perylene and penta-aromatic hydrocarbons were determined in sediments as part of a study that was dedicated to the aquatic ecosystem of Oginigba Creek (southern Nigeria) in order to carry out a critical corroboration of occurrence and diagenetic evolution of perylene in the sediments of the creek. The results show that the annual mean levels of perylene ranged from 396.27- 507.19 mg/g dry weight at the various Stations. The observed values for total penta-aromatic hydrocarbons werehigh (867.3 - 1243.14mg/g dryweight) in all the stations sampledOne origin index or concentration ratio of Ip/Ip+BghiP was also used to evaluate the suitability of the penta-aromatic hydrocarbons as a tracer to distinguish between contaminations arising from different sources. The values for the sampling stations therefore ranged from 0.41 to0.81. Acritical appraisal of the PAH index, consequently, suggested that petroleum combustion is the major penta-aromatic hydrocarbon source in the sediments of the creek. The PAH group profile shows that perylene was high in the sediments and would pose apparent effects in fauna. The high concentration of perylene in the sediments was also indicative of an in situ biogenic derivation. Furthermore, a concentration of perylene ≥ 31.88% of total penta-aromatic hydrocarbons established a credible diagenetic origin

Preliminary assessment of trace metals and polycyclic aromatic hydrocarbons in the sediments

Total concentrations of Cd, Cr, Co, Fe, Pb, Ni, Mn and Zn were determined by atomic absorption spectrophotometry in the surface sediments of Taylor Creek, Southern Nigeria. The most concentrated trace metals, ranging from 113.2 to 5160.7 mg/g-dry weights were Fe, Pb, Mn, Ni and Zn. There was no significant variation in sediment-associated metal levels (P>0.05). The Metal Pollution Index (MPI) was highest at Agbia/Nedugo and is attributed to local contamination of the Creek. The concentrations of low molecular weight polycyclic aromatic hydrocarbons (PAHs) were also detected and quantified in the sediments by capillary gas chromatography equipped with a flame ionization detector. The concentration levels of 178.1-1266.3 mg/g-wet weights were high for the PAHs. The results indicate that the pollutants, which are bio-accumulatable, could contribute to inferior biodiversity, and shifts in community composition from sensitive to tolerant taxa

Relationships Between Heavy Metals in Shrimp ( Macrobrachium felicinum ) and Metal Levels in The Water Column and Sediments of Taylor Creek

Heavy metals in the aquatic environment have todate originated fundamentallyfrom naturally occurring geochemical resources. Nonetheless, this has been enhanced by anthropogenic activities resulting in pollution. Consequently, relationships and partitioning of heavy metals in the dissolved phase, suspended particulate matter (SPM), sediments and shrimp ( Macrobrachium felicinum ) were investigated in five selected sites along Taylor creek, southern Nigeria. The degree of relationships between the various metals was dissimilar in each of the investigated matrices. In the matrices studied, not several significant relationships (P<0.05) were obtained. Only Ni-Cd (r=0.95), Mn-Cd (r=0.63), Mn-Ni (r=0.64) were associated in the sediments and in SPM, Zn-Ni (r=0.72), which suggests that the sources were not common for both matrices. In the dissolved phase, no strong relationships (P<0.05) between the heavy metals were obvious. The best relationships were observed for Ni-Zn (r=0.72) and Cd-Pb (r=0.65). Partitioning coefficients (Kd) of heavy metals between dissolved phase and SPM were generally low, which is typical for fresh water ecosystems and fairly stable over the creek all through the seasons. Furthermore, the bio-concentration factors (BCFs) of Macrobrachium felicinum were low unlike those of other natural waters. Thus, the physical state of the aquatic ecosystem points to the fact that the heavy metals bio-accumulated by Macrobrachium felicinum give cause for concern when viewed in perspective to community health issues, as the communities along the creek depend directly on shrimps as a protein source

Influence of vehicular density on the distribution pattern of lead and cadmium in road dust of Port Harcourt city, Nigeria

No Abstract.International Journal of Natural and Applied Sciences Vol. 4 (1) 2008: pp. 29-3

Composition and source diagnostics of polycyclic aromatic hydrocarbons in sediments from Elelenwo Creek, southern Nigeria

The survey of polycyclic aromatic hydrocarbons (PAHs) and their relation to potential pollution sources was carried out in sediments from Elelenwo Creek, southern Nigeria. Total PAH concentrations varied from 4238.00 to 5490.84 Bg/g dry weights in sediments. The 2, 3-ring PAHs were not dominant in sediments (22.43%). Of the 2, 3-ring PAHs, the most abundant in the sediments was acenaphthylene. Four origin indices or concentration ratios of PAH isomer pairs were used to evaluate the suitability of these compounds as tracers to distinguish between the contamination arising from different sources. A critical appraisal of PAH indices, therefore, suggested that  combustion processes were the sources of PAH in the sediments. Relative PAH patterns in sediments were also evaluated using principal component analysis, and were found to correlate with the PAH patterns of the different potential contamination sources. This indicates that the PAHs, which are bioaccumulatable, possibly will impact on fauna.Keywords: Creek, sediments, polycyclic aromatic hydrocarbons, fauna, Nigeri

Temporal trends of heavy metals in shrimps (Macrobrachium macrobrachion) from a non-tidal freshwater ecosystem

No Abstract.International Journal of Tropical Agriculture and Food Systems Vol. 2 (1) 2008: pp. 60-6

Survey of heavy metals in the catfish Synodontis clarias

Elevated levels of heavy metals in the catfish Synodontis clarias can be a good indication of pollution of an aquatic ecosystem due to anthropogenic influence. The concentrations of Zn, Cd, Pb, Mn and Ni were determined in Synodontis clarias caught along a section of Taylor Creek and its associated tributaries. Samples were collected bimonthly between July 1999 and June 2000 in five stations. The metals: Zn, Cd, Ni, Pb and Mn were recorded in appreciable quantities, signifying their bioavailability. The levels of Zn, Cd, Ni, Pb and Mn may have obvious health implications on the rural communities that depend on fish species as fish supplement in view of its rich protein content and its bio-economic value. Generally, the sources of the metals in the catfish appear to be point and diffuse which include rural and agricultural runoff sources in the catchments area. However, the presence of an oil industry activity (Etelebou oil field and flow station) in one of its tributaries appears to be the major point source of the metal pollutants

Partitioning Characteristics of Heavy Metals in a Non-Tidal Freshwater Ecosystem

Trace metals in the aquatic environment have to date come essentially from naturally occurring geochemical resources. However, this has been enhanced by anthropogenic activities resulting in pollution. Consequently, correlations and partitioning of trace metals in the dissolved phase, suspended particulate matter (SPM) and sediments were investigated in five selected sites along the Taylor Creek, southern Nigeria. The degree of correlations between the various metals was different in each of the investigated matrices. In the matrices studied, not many significant correlations (P<0.05) were recognized. Only Ni-Cd (r=0.95), Mn-Cd (r=0.63), Mn-Ni (r=0.64) are correlated in the sediments and in SPM, Fe-Cr (r=0.54) and Zn-Ni (r=0.72), which suggests that the sources are not common for both matrices. In the dissolved phase, no strong correlations (P<0.05) between the trace metals are obvious. The best correlations are observed for Ni-Zn (r=0.72) and Cd-Pb (r=0.65). Partitioning coefficients (Kd) of trace metals between dissolved phase and SPM aregenerally low, which is typical for fresh water ecosystems and fairly stable over the creek all through the seasons. Thus, the state of the aquatic ecosystem indicates that the trace metals, which are bio-accumulatable, could contribute to inferior biodiversity and shifts in community composition from sensitive to tolerant taxa

Identification of perylene in sediments: Occurrence and diagenetic evolution

Perylene and penta-aromatic hydrocarbons were determined in sediments as part of a study that was dedicated to the aquatic ecosystem of Elelenwo Creek (Southern Nigeria) in order to carry out a critical corroboration of occurrence and diagenetic evolution of perylene in the sediments of the creek. The results show that the annual mean levels of Benzo [g, h, i] Perylene ranged from 209.00 – 245.28 μg/kg dry weight at the various stations sampled. Meanwhile, Station 3 recorded the highest mean level of 245.28 μg/kg dry weight. The observed values for total penta-aromatic hydrocarbons were high (787.00 -1154.36μg/kg dry weight) in all the stations sampled. In addition, the highest mean value of 1154.36μg/kg dry weight was again recorded at station 3 for the penta-aromatic hydrocarbons. One origin index or concentration ratio of Ip/Ip+BghiP was also used to evaluate the suitability of the penta-aromatic hydrocarbons as a tracer to distinguish between contaminations arising from different sources. The values for the sampling stations therefore ranged from 0.41 to 0.43. A critical appraisal of the PAH index, consequently, suggested that petroleum combustion is the major penta-aromatic hydrocarbon source in sediments of the creek. The PAH group profile shows that perylene was high in the sediments and would pose apparent effects in fauna. The high concentration of perylene in the sediments was also indicative of an in situ biogenic derivation. Furthermore, a concentration of perylene > 10 % of total penta-aromatic hydrocarbons established a credible diagenetic origin