Assessment of surface water quality during different tides and an anthropogenic impact on coastal water at Gulf of Kachchh, West Coast of India.

The port-based activity is often associated with industrial growth in the hinterland and similar phenomenon reported from the Gulf of Kachchh, India. Industrialization exerts pressure on coastal water through the release of waste water or effluents which influence the entire marine ecosystem. The present paper tries to evaluate the variation in the water quality during the high tide and low tide in relation to the anthropogenic or natural influence in Gulf of Kachchh. The tidal variation is important as it reflects the influence of the land-based activity on the coastal waters. To prove this logic, a series of stations were taken along the coastal water and statistical analysis, viz., Pearson correlation, Box plot, hierarchical cluster analysis (HCA), and factor analysis (PCA/FA) were conducted. Pearson correlation and Box plot represent visual impact of parameter variations in respected tides. The chemometric analysis, i.e., HCA and PCA/FA, clearly indicates an anthropogenic impact on coastal water. The results of HCA revealed that major anthropogenic and domestic impacts were found at various stations during the low tide. The HCA points out that an anthropogenic and the tidal activity in the Gulf of Kachchh influence the physical water quality parameters like pH, salinity, dissolved solid, oxygen, turbidity, sulfate, and nutrients in the coastal ecosystem. The PCA/FA further ascertains the finding of HCA analysis that the state of the art of the water quality of coastal ecosystem has direct relevance with the land-based activities and sewage outfall points. Tide-based control on the water quality parameters was evident that the high tide nutrients like phosphates and nitrogen were high, while during the low tide, temperature, salinity, total solids, and sulfate showed higher concentrations. The findings of the paper will be useful for developing effective management strategies for policy makers or stakeholders operating in the coastal area.

Exploring bacterial communities through metagenomics during bioremediation of polycyclic aromatic hydrocarbons from contaminated sediments.

The goal of this study was to evaluate the degradation effectiveness of PAHs degrading bacteria at the mesocosm level, including Stenotrophomonas maltophilia (SC), mixed culture (MC), and enriched native microflora (EC) at the mesocosm level. Maximum degradation was found in the mesocosm MC (26.67 %), followed by SC (25.08 %) and EC (18.25 %) after 60 days. Thus, mixed culture and Stenotrophomonas maltophilia could be a game changer in the PAHs bioremediation at the chronically contaminated sites. MiSeq sequencing has revealed dominancy of γ-Proteobacteria, α-Proteobacteria, ß-Proteobacteria at class level and Sphingomonadales, oceanospirillales, Rhodothermales at Order level. Families Alcanivoracaceae, Alteromonadaceae, Nocardiaceae, Rhodospirillaceae and genus Stenotrophomonas, Alcanivorax, Methylophaga, Fluviicola and Rhodoplanes were considerably increased which play key role in the PAHs degradation. Dominant bacterial communities have revealed resilience community to enable potential PAHs degradation process in all the mesocosms. To the best our knowledge this is the first ever attempt in PAHs biodegradation study conducted at the mesocosm level mimicking natural environmental conditions. Consequently, this study could be a benchmark against which future progress studies for the policy makers and stakeholders to design appropriate bioremediation study for the historically PAHs polluted contaminate sites.

Assessment of surface water of Gulf of Kachchh, west coast of India: A chemometric approach.

The present study is aimed at investigation of surface water quality of Gulf of Kachchh (GoK), Gujarat. The main objective of this study was to convert complex dataset of water quality parameters from GoK into comprehensive, simple and interpretable observations. Hence, physico-chemical parameters and nutrients of surface water from GoK were analyzed. Chemometric results indicated that oxygen, salinity, dissolved solids, nutrient and natural conditions were the factors that affected surface water quality. The water quality index was calculated to identify water quality classes to evaluate the spatio-seasonal trend in the study area. The results revealed that water quality was moderate in summer, worst in pre-monsoon and best in post-monsoon. The study also highlighted that Marine National Park (Central GoK) was observed to be comparatively in good condition with abundant marine biodiversity. Thus, the results of chemometric study of water quality parameters can be a valuable tool for government authorities for sustainable development of GoK.

Concentrations, input prediction and probabilistic biological risk assessment of polycyclic aromatic hydrocarbons (PAHs) along Gujarat coastline.

A comprehensive investigation was conducted in order to assess the levels of PAHs, their input prediction and potential risks to bacterial abundance and human health along Gujarat coastline. A total of 40 sediment samples were collected at quarterly intervals within a year from two contaminated sites-Alang-Sosiya Shipbreaking Yard (ASSBRY) and Navlakhi Port (NAV), situated at Gulf of Khambhat and Gulf of Kutch, respectively. The concentration of ΣPAHs ranged from 408.00 to 54240.45 ng g-1 dw, indicating heavy pollution of PAHs at both the contaminated sites. Furthermore, isomeric ratios and principal component analysis have revealed that inputs of PAHs at both contaminated sites were mixed-pyrogenic and petrogenic. Pearson co-relation test and regression analysis have disclosed Nap, Acel and Phe as major predictors for bacterial abundance at both contaminated sites. Significantly, cancer risk assessment of the PAHs has been exercised based on incremental lifetime cancer risks. Overall, index of cancer risk of PAHs for ASSBRY and NAV ranged from 4.11 × 10-6-2.11 × 10-5 and 9.08 × 10-6-4.50 × 10-3 indicating higher cancer risk at NAV compared to ASSBRY. The present findings provide baseline information that may help in developing advanced bioremediation and bioleaching strategies to minimize biological risk.

Polycyclic aromatic hydrocarbons (PAHs) at the Gulf of Kutch, Gujarat, India: Occurrence, source apportionment, and toxicity of PAHs as an emerging issue.

The present study extrapolates the assessment and characterization of a barely studied region, the Gulf of Kutch, (near Jamnagar), Gujarat, India, in terms of PAH exposure, adverse effects caused by them, and various toxicological indices showing the catastrophic effects of their elevated concentrations. ΣPAH concentration in the site ranged from 118,280 to 1,099,410ngg-1 dw, with a predominance of 2-3-ring PAHs (79.09%) as compared to 4-5- and 6-ring PAHs (20.91%). The concentrations of carcinogenic PAHs were found to be between 8120 and 160,000ngg-1 dw, with a mean of 63,810ngg-1 dw, which is much higher than normal acceptable values. The toxic equivalent quotient for 6CPAHs ranged from 150.47 to 26,330ngg-1 BaPeq, encompassing 50.63% of ΣPAH toxicity. This toxicological profile of the present study site would be of paramount importance as it offers fresh information regarding the load of legacy pollutants such as PAHs and the inputs and methods to cope with their extremely high concentrations in less explored marine habitats.

Distribution, sources and ecological risk assessment of PAHs in historically contaminated surface sediments at Bhavnagar coast, Gujarat, India.

The concentration, distribution and ecological risk of polycyclic aromatic hydrocarbons (PAHs) have been investigated in surface sediments near Bhavnagar coast. The concentration of ∑PAHs ranged from 5.02 to 981.18 µg g(-1) dry weight, indicating heavy pollution compared to other historically polluted study sites. It was found to be introduced via mixed origins such as burning of gas, oil, coal, production of petrochemicals, cement, and rubber tires. Domestic fuel burning and motor vehicles are also culprits for air pollution. Industrial effluents and accidental oil spillage can also be considered. PAHs can be exposed through air, water, soil and food sources including ingestion, inhalation, and dermal content in both occupational and non-occupational levels by single or sometimes multiple exposures routes concomitantly. Furthermore, diagnostic ratios, statistical principal component analysis (PCA) and hierarchical cluster analysis (HCA) models have confirmed that the sources of PAHs were both - petrogenic and pyrogenic. For both the sites, assessment of ecological risk of the elevated levels of these pollutants has been exercised based on toxic equivalency factors (TEFs) and risk quotient (RQ) methods. The composite results indicated accurately that both the sites, bears potentially acute and chronic health hazards such as decreased immune functionality, genotoxicity, malignancy and developmental malfunctions in humans. The sites studied here and the workers have been exposed to hazardous pollutants for a longer period of time. Evidences indicate that mixtures of PAHs are carcinogenic to humans, based on occupational studies on workers, exposed to these pollutants. Hence, the present study and statistical approaches applied herein clearly indicate the historic mix routes of PAHs that resulted in magnified concentrations leading to high ecosystem risk. Thus, the scientific communities are urged to develop strategies to minimize the concentrations of PAHs from the historically impacted coastlines, thereby concerning for the future investigations and restoration of these sites.