Open Access Original Research Article

The Full Hierarchical Structuration of Species Abundances Reliably Inferred from the Numerical Extrapolation of Still Partial Samplings: A Case Study with Marine Snail Communities in Mannar Gulf (India)

Jean Béguinot

Asian Journal of Environment & Ecology, Page 1-27
DOI: 10.9734/AJEE/2018/43918

The detailed analysis of Species Abundance Distributions (“S.A.D.s”) can shed light on how member-species organize themselves within communities, provided that the complete distribution of species abundances is made available first. In this perspective, the numerical extrapolation applied to incomplete “S.A.D.” can effectively compensate for S.A.D.s incompleteness, when having to deal with substantially incomplete samplings. Indeed, almost as much information can be released from extrapolated “S.A.D.s” as would be obtained from truly complete “S.A.D.s”, although the taxonomic identities of unrecorded species remain of course ignored by numerical extrapolation.

To take full advantage of this new approach, a recently developed procedure allowing the least-biased numerical extrapolation of “S.A.D.s” has been applied to three partially sampled gastropods communities associated to coral-reef in Mannar Gulf (S-E India).

The following main results were derived from the three numerically completed “S.A.D.s”: (i) once completed, all three numerically “S.A.D.s” fairly well comply with the log-normal model, suggesting that, in all three communities, the process of hierarchical structuration of species abundances likely involves the combined contributions of many independent factors; (ii) moreover, the same holds true for each of the two coexisting feeding guilds (primary and secondary consumers) considered separately; (iii) when compared to secondary consumers, the guild of primary consumers has a much lower species richness but, on the other hand, exhibits a more strongly structured distribution of species abundances, which materializes not only in term of the apparent unevenness of species abundances but also after having disentangled the genuine intensity of the underlying process driving the hierarchical structuration.

All the preceding features are shared in common by the three communities studied, in line with the similarity of their environmental contexts. Only minor features can actually slightly distinguish between communities, reflecting the difference in distances between them.


Open Access Original Research Article

Water Quality Assessment of Karrnaphuli River, Bangladesh Using Multivariate Analysis and Pollution Indices

Mahmudul Karim, Sujan Kanti Das, Shujit Chandra Paul, Mohammad Farhan Islam, Md. Shahadat Hossain

Asian Journal of Environment & Ecology, Page 1-11
DOI: 10.9734/AJEE/2018/43015

The Karrnaphuli river is one of the polluted river of Chittagong originating from the Lushai Hills in India which is being polluted recently by various industries located around it. The primary objective of this study was to determine the water quality status of the most polluted area of Karrnaphuli river along with the root causes of pollution. The study involved the determination of physical parameters like temperature, color, electrical conductivity, odor, turbidity and other chemical parameters like potential of hydrogen (pH), dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD) etc. of the most polluted zone of Karrnaphuli river. From the parameters investigated, evaluation of water quality was done on the basis of standard Water Quality Index (WQI) and Comprehensive Pollution Index (CPI). Principal Component Analysis (PCA) was used to extract the parameters that were most important in assessing variation in water quality. The WQI value indicates that around 40% of the sampled stations water quality is of bad grade, about 40% of water quality is of low grade and 20% water quality was ranged from moderate to good quality. However, CPI values indicate that all of the sampling station water is severely polluted. Four Principal Components were identified to be responsible for the data structure explaining 94% of the total variance of the dataset. The sample sites were highly polluted with different wastes generated from various industries situated in the bank of Karrnaphuli River.


Open Access Original Research Article

Determination of the Level of Heavy Metals in Some Selected Vegetables from an Irrigated Farmland of Kudenda in Kaduna Metropolis, Nigeria

Galo Yahaya Sara, Andrew Emmanuel, Innocent Joseph, J. E. Eneche, Mary Sara Galo

Asian Journal of Environment & Ecology, Page 1-8
DOI: 10.9734/AJEE/2018/39926

Heavy metal contamination of soil resulting from wastewater irrigation is a cause of serious concern due to the potential health risk of consuming contaminated produce. The use of wastewater for irrigation increases the contamination of heavy metals (Cd, Cu, Pb, Mn, Ni, Zn etc) in the plants. In this study, an assessment is made on the impacts of wastewater irrigation on heavy metals (Cd, Cu, Pb, Mn, Ni and Zn) contamination on vegetables cultivated in an irrigated farmland of Kudenda in Kaduna Metropolis, Nigeria. Samples of water, soil and some selected vegetables were collected and analysed for Cd, Cu, Pb, Mn, Ni and Zn using Buck scientific VGP 210 Atomic Absorption Spectroscopy (AAS). The wastewater used for irrigation had the following concentration 0.006±0.003 µg/mL Cd, 0.002±0.001 µg/mL Cu, 0.002±0.001 µg/mL Mn, 0.002±0.001 µg/mL Zn, while Pb and Ni were below detectable limit (BDL). The level of heavy metals in the vegetables under study differs with vegetables species. Cd level in tomato, cabbage and garden egg is the same 0.01±0.00 μg/g, and the level in one of the soil sampling site is found to be 0.03±0.01. The level of heavy metal was higher in soil than in vegetables studied. Accumulation of heavy metals varied from vegetable to vegetable. The mean concentrations of all the heavy metals studied were below the internationally permissible limits set by FAO/WHO and USEPA.


Open Access Original Research Article

A Study of Potential Corrosivity of Borehole Waters in Eket, Nigeria by Saturation Index Measurement

Usoro M. Etesin, Thomas Harry, Ibanga O. Isaac, Ufikairom G. Isotuk

Asian Journal of Environment & Ecology, Page 1-13
DOI: 10.9734/AJEE/2018/43423

A study of water chemistry in some boreholes in Eket, Nigeria, was conducted to determine the calcium carbonate saturation index, in order to establish the corrosion tendency of the waters towards metal substrates in piping systems, boilers, heat exchangers and submersible pumps. Calcium carbonate saturation index using Langelier system was determined to be more negative     (- 4.16 to – 5.2) below the optimum range of – 0.5 to + 0.5 for water that is in equilibrium with calcium carbonate. The water saturation pH (pHs) determined for the waters sampled in the area had values that ranged from 8.82 to 9.55, with a mean value of 9.09. The values were far above the pH values of the waters from all the locations sampled, which ranged from 4.12 to 5.34, with a mean pH of 4.48. The water chemistry was of same characteristic for all the studied locations, indicating that the waters were drawn from same regional aquifer, have same corrosive tendency and the possibility of metal substrates to be attacked by water used for both industrial and domestic purposes in the study area. The more negative the calcium carbonate saturation index, the greater the possibility of the water in its corrosive action especially in oxygenated waters. Therefore, the waters in Eket are likely to exhibit remarkable corrosive tendency against metal substrates. The implication of this finding is that in the study area, there has to be a strategic corrosion control program in piping systems and industrial equipment such as heat exchangers, boilers, domestic water heaters and submersible pumps in tackling corrosion challenges.


Open Access Original Research Article

Water Quality Contamination and Mortality of African Mud Catfish (Clarias gariepinus; Burchell, 1822) Fingerlings Exposed to Paint Effluents

Bassey Esio Otong, Akaninyene Paul Joseph, Finian Tobias Okoro

Asian Journal of Environment & Ecology, Page 1-12
DOI: 10.9734/AJEE/2018/44003

The toxicological effects of paint effluents on Clarias gariepinus fingerlings and its aquarium water was studied. Ten fingerlings were used in each aquarium and exposed to 4 different concentrations of the effluent along with the control group. The fingerlings were exposed to 0%, 85%, 90%, 95% and 100% concentration of the effluent in a triplicate experiment. A total of 150 C. gariepinus fingerlings with a mean weight of 1.92 ± 0.34 g were used throughout the study. The physico-chemical parameters of the culture water varied with an increase in paint effluent concentration. Temperature, pH and conductivity increased with increasing concentration of effluent in most cases, while DO decrease with increase in effluent concentration. The mortality data trend of fingerlings exposed to the toxicant was concentration dependent. The 96 hours LC50 value with 95% confidence limit of C. gariepinus exposed to the effluent was 39.81% ± 12.68, and was significant with a determination coefficient (r2) of 0.95 at P<0.05. The high LC50 value for the fingerlings exposed to the paint effluent showed that the effluent is less toxic, but still caused mortality to the fingerlings at increased concentration. Although the paint effluents are less toxic, it was still able to alter the physico-chemical parameters of the culture water as well as cause mortality to fingerlings. As a result, the study emphasizes that paint industries should treat their effluents properly, reduce the microbial and chemical load before discharging into the environment. Also, the Government should enforce laws and regulations prohibiting indiscriminate discharge of untreated effluents by industries into drainage channels and any water body, because failure to enforce these laws could lead to the mortality of biological organisms, pollute organisms in surrounding water by altering the physico-chemical parameters and cause harmful diseases to humans that consume the resources from this polluted aquatic environment.