Contamination Of Coastal Waters Research Articles

A Sustainable Restoration Plan for Gaza

Purpose: Since the outbreak of the Gaza war, innumerable discussions for resolving the conflict have emerged considering governance, security, equity and feasibility. Any discussion involving the aftermath of the fighting in this embattled area must also include a focus on sustainability. The article highlights the primary environmental challenges associated with post-war ecological restoration. Methodology: This article represents an historical analysis, reporting the results of a desk study, based on academic sources, reports of internation agencies, civil society and government data. Findings: In recent decades, Gaza’s environment increasingly reflects the adverse impacts of mounting demographic density, resource exploitation, poor management and significant contamination. Degraded ground water quality, sewage contamination of coastal waters and debris from inadequate solid waste infrastructure, traditionally, have been the primary environmental hazards. The ongoing military conflict has only exacerbated these acute problems, adding additional risks from airborne particles from the massive damage sustained by local buildings, especially when structures contain asbestos. Unique Contribution to Theory, Practice and Policy: The article offers a brief historic review of Gaza’s natural resources, the drivers of the acute environmental degradation and priority action items for a sustainable strategy for Gaza and its residents’ future.

Detection of Toxoplasma gondii in wild bivalves from the Kerguelen and Galapagos archipelagos: influence of proximity to cat populations, exposure to marine currents and kelp density

Oocysts of the protozoan Toxoplasma gondii are found in felid feces and can be washed into coastal waters, where they persist for months, attaching to algae and accumulating in invertebrates. We used wild bivalves to assess contamination of coastal waters of the Kerguelen and Galapagos archipelagos by this zoonotic parasite. Additionally, we leveraged the contrasting situations of these archipelagos to identify some potential drivers of contamination. In the Galapagos, with a cat density reaching 142 per km2, 15.38% of the sampled oysters (Saccostrea palmula) tested positive for T. gondii by quantitative real-time PCR (qPCR) (n = 260), and positive samples were found in all eight sampling sites. In Kerguelen, with 1-3 cats per km2, 40.83% of 120 tested mussels (Mytilus edulis platensis) were positive, and positive samples were found in four out of the five sampling sites. These findings provide evidence of T. gondii contamination in the coastal waters of these archipelagos. Furthermore, T. gondii-positive bivalves were found on islands located 20 km away (Galapagos) and 5 km away (Kerguelen) from the nearest cat population, indicating that T. gondii oocysts can disperse through waterborne mechanisms over several kilometers from their initial deposition site. In the Galapagos, where runoff is infrequent and all sites are exposed to currents, the prevalence of qPCR-positive bivalves did not show significant variations between sites (p = 0.107). In Kerguelen where runoff is frequent and site exposure variable, the prevalence varied significantly (p < 0.001). The detection of T. gondii in Kerguelen mussels was significantly correlated with the site exposure to currents (odds ratio (OR) 60.2, p < 0.001) and the on-site density of giant kelp forests (OR 2.624, p < 0.001). This suggests that bivalves can be contaminated not only by oocysts transported by currents but also by consuming marine aggregates containing oocysts that tend to form in kelp forests.

Heavy metals contamination in coastal waters of South Vietnam

Heavy metals contamination in coastal waters of South Vietnam

Triazine herbicide reduced the toxicity of the harmful dinoflagellate Karenia mikimotoi by impairing its photosynthetic systems

Triazine herbicides are common contaminants in coastal waters, and they are recognized as inhibitors of photosystem II, causing significant hinderance to the growth and reproduction of phytoplankton. However, the influence of these herbicides on microalgal toxin production remains unclear. This study aimed to examine this relationship by conducting a comprehensive physiological and 4D label-free quantitative proteomic analysis on the harmful dinoflagellate Karenia mikimotoi in the presence of the triazine herbicide dipropetryn. The findings demonstrated a significant decrease in photosynthetic activity and pigment content, as well as reduced levels of unsaturated fatty acids, reactive oxygen species (ROS), and hemolytic toxins in K. mikimotoi when exposed to dipropetryn. The proteomic analysis revealed a down-regulation in proteins associated with photosynthesis, ROS response, and energy metabolism, such as fatty acid biosynthesis, chlorophyll metabolism, and nitrogen metabolism. In contrast, an up-regulation of proteins related to energy-producing processes, such as fatty acid β-oxidation, glycolysis, and the tricarboxylic acid cycle, was observed. This study demonstrated that dipropetryn disrupts the photosynthetic systems of K. mikimotoi, resulting in a notable decrease in algal toxin production. These findings provide valuable insights into the underlying mechanisms of toxin production in toxigenic microalgae and explore the potential effect of herbicide pollution on harmful algal blooms in coastal environments.

Byssus of Green-Lipped Mussel Perna viridis as a Biomonitoring Biopolymer for Zinc Pollution in Coastal Waters.

The present study aimed to confirm the use of the byssus (BYS) of the green-lipped mussel Perna viridis as a biomonitoring biopolymer for zinc (Zn) by comparing it to copper (Cu) and cadmium (Cd) pollution in coastal waters under experimental field conditions, based on the transplantation of caged mussels between polluted and unpolluted sites in the Straits of Johore (SOJ). Four important evidential points were found in the present study. First, the 34 field-collected populations with BYS/total soft tissue (TST) ratios > 1 indicated that the BYS was a more sensitive, concentrative, and accumulative biopolymer for the three metals than TST. Significant (p < 0.05) and positive correlations between BYS and TST in terms of the levels of the three metals were observed. Second, the data obtained in the present study were well-supported by the interspecific comparison, which indicated that the BYS of P. viridis was a significantly better biomonitoring biopolymer for the identification of coastal areas exposed to Zn, Cd, and Cu pollution and played the role of an excretion route of metal wastes. Third, the higher positive correlation coefficients for the metals between the BYS sedimentary geochemical fractions than the TST sedimentary geochemical fractions indicated that the BYS was more reflective of metal bioavailability and contamination in coastal waters. Fourth, and most importantly, the field-based cage transplantation study clearly indicated the accumulation and elimination of the three metals by the BYS in both polluted and unpolluted sites in the Straits of Johore. In sum, the BYS of P. viridis was confirmed as a better biopolymer than TST for Zn, as well as Cd and Cu, bioavailability and contamination in tropical coastal waters.

Impact of the MV X-Press Pearl ship disaster on the coastal environment from Negambo to Benthota in Sri Lanka

In Sri Lanka, the “biggest maritime disaster” occurred on May, 2021. The ship carried 1486 containers of chemicals, including low and high-density polyethene, methanol, sodium methoxide, nitric acid, urea, and lubricant oil. This multi-faceted and complicated disaster involves numerous environmental issues that could have significant consequences. The present study aimed to evaluate chemical contamination in coastal waters from Negambo to Bentota by analyzing water samples, biological samples, phytoplankton, biotoxins, and heavy metals. The research findings revealed that the average nitrate concentration in the study area’s coastal waters ranged from 0–0.19 mg/L. The highest nitrate and phosphate concentrations were recorded near the MV X-Press Pearl ship. The chlorophyll-a concentrations in the coastal belt ranged from 1.8 ± 0.6 to 11.8 ± 1.1 mg/L, and the highest was near the MV X-Press Pearl ship disaster in X2. The most abundant phytoplankton recorded were harmful diatoms; (Nitzcha sp., Amphora sp., Chaetoceros sp. and dinoflagellates; (Gymnodinium sp., Ceratium furca, Prorocentrum sp., Peridinium sp., Dinophysis caudata in the sampling location near the ship and where the highest Saxitoxin concentration was detected (0.230.06 g L−1). It might be due to the release of the high concentration of phosphate and nitrogen, which directly affect the growth of algae, diatom, and dinoflagellates following increasing of chlorophyll-a content. The location, which was extremely close to the MV X-Press Pearl ship, sank and had the highest oil and grease content. Lead (Pb), Zinc (Zn), Copper (Cu), Chromium (Cr), Cadmium (Cd) and Nickel (Ni) were the most common heavy metal pollutants in the study area’s coastal waters. Thus, the results of the present study revealed that the ship disaster had a significant impact on coastal environment water quality which may affect ocean biodiversity, the ocean’s health, fishery resources and the economy of the fishing community and seafood industry.

Microplastic contamination in coastal waters of South Larompong, Luwu, South Sulawesi, Indonesia

Microplastic contamination in the aquatic environment poses a serious threat to the survival of the ecosystem because it is persistent. This study aims to analyze the concentration of microplastics in the water column in the coastal waters of South Larompong. Sampling was carried out using the volume reduce method with the neuston net at four stations, namely Bonepute Beach, Ponnori Beach, Babana Beach and Damaci Beach. The results showed that there was microplastic contamination and found as many as 386 microplastic particles with an average concentration of 2.68 particles/m3. The results of the analysis of microplastic concentrations showed significant differences (P&lt;0.05) between stations. The highest concentrations of microplastics are found on Bonepute Beach which is an area of aquaculture, fishing and densely populated settlements, then followed by Ponnori Beach which is a tourist area. Meanwhile, the lowest microplastic concentrations are found on Babana Beach, which is the estuary area of the Temboe River and Damaci Beach which is a nearby area. Several forms of microplastics were found, namely granules, fibers, films and fragments which were the most dominant forms. Several colors of microplastics were found, namely blue, brown, green, red, white, and black which were the most dominant colors. There are two types of polymer found, namely HDPE (High Density Polyethylene) and PVA (Polyvinyl alcohol). The conclusion of this study is that the coastal waters of South Larompong have been contaminated with microplastics so that more attention is needed regarding the handling of plastic waste, especially microplastics.

Addressing the Governance of Harmful Algal Bloom Impacts: A Case Study of the Scallop Fishery in the Eastern French Coasts of the English Channel

Harmful Algal Blooms (HAB) are phenomena that result from alterations to ecosystems. Due to their potential toxicity, the level of danger depends on the species concerned, their frequency and intensity. They can cause impacts on biodiversity and on the anthropic activities that take place in maritime and coastal areas. Primary industries such as shellfish fisheries are mainly affected. To deal with this issue, the French administration has built a governance system based on two pillars. The first relies on a water quality monitoring system that assesses the risks of HAB contamination of coastal waters. The second is a regulatory system of production and commercial bans of seafood products from the impacted areas. This public action has two objectives. The first is human health-related and aims to protect consumers of seafood. The second is economic-based and aims to minimize the economic impacts associated with the commercial bans suffered by the businesses concerned. These two objectives may appear to be antagonistic. Using the case study of the French scallop fishery in the eastern Channel and based on an analysis of the commercial bans associated with HAB and associated potential economic impacts, this paper analyses the governance scheme dealing with HAB events in France. The authors highlight that this governance is not only a matter of applying administrative closures when toxicity thresholds are exceeded, but is a dynamic decision-making process involving experts and the Administration that attempts to balance acceptable health risks and economic impacts.

Characteristics and Health Risk Assessment of Heavy Metal Pollution in Haikou Bay and Adjacent Seas.

Heavy metal contamination in coastal waters may pose a serious threat to aquatic products and human health. This study aimed to gain a better understanding of the pollution-induced by heavy metals in Haikou Bay and adjacent seas and assessed the potential ecological risk. The spatial distributions of heavy metals including Cu, Pb, Zn, Cd, Cr, Hg, and As were analyzed in the surface and bottom water, surface sediment, and five species of fish collected from Haikou Bay and adjacent seas. For seawater, the results showed that the horizontal distribution of the seven heavy metal elements in the study area had no uniform pattern due to the influence of complex factors, such as land-based runoff, port shipping, and ocean current movement. In contrast, the vertical distribution of these heavy metal elements, except for Zn and Cd, showed high concentrations in the surface water and low concentrations in the bottom water. Due to the symbiotic relationship between Zn and Cd, the distributions of these two elements were similar in the study areas. Different from the complex distribution of heavy metals in water, the highest concentrations of these elements in surface sediment all occurred at station 11 except for Pb. Our study revealed that organic carbon and sulfide are important factors affecting the heavy metal concentrations in the surface sediments. Heavy metals in waters and surface sediment were lower than the quality standard of class I according to the China National Standard for Seawater Quality and the sediment quality, except for Zn in water, suggesting that the seawater and surface sediment in Haikou Bay and adjacent seas has not been polluted by heavy metals. Additionally, the heavy metal As was the main element affecting the quality of fish in this study area, and attention should be paid in the future. The target hazard quotient (THQ) values of seven heavy metal elements in fish were all lower than 1.0, indicating that eating fish in this area will not pose a risk to human health. These results provide valuable information for further understanding the status of heavy metal pollution in Haikou Bay and adjacent seas and the development of targeted conversation measures for the environment and fish consumers.

Trace element bioaccumulation in edible red seaweeds (Rhodophyta): A risk assessment for consumers

As a precursor to risk assessment and risk management through consuming contaminated seafood, food safety needs to be quantified and assured. Seaweed is an increasing dietary component, especially in developing countries, but there are few studies assessing uptake rates of contaminants from this route. As such, the present study determined likely human uptake due to the trace elemental (Fe, Mn, Ni, Cu, Zn, Se, Hg, and As) concentrations in the edible red seaweeds (Rhodophyta) Gelidium pusillum and Hypnea musciformis, growing in the industrialised Cox's Bazar coastal area of Bangladesh. Metal and metalloid concentrations in G. pusillum were in the order (mg/kg): Fe (797 ± 67) > Mn (69 ± 4) > Ni (12 ± 5) > Zn (9 ± 4) > Cu (9 ± 4) >Se (0.1 ± 0.1) > Hg (0.1 ± 0.01), and in H. musciformis: Fe (668 ± 58) > Mn (28 ± 5) > Ni (14 ± 2) > Zn (11 ± 5) > Cu (6 ± 4) >Se (0.2 ± 0.03) > Hg (0.04 ± 0.01). Despite the industrial activities in the area, and based on 10 g. day−1 seaweed consumption, it is concluded that these concentrations pose no risk to human health as part of a normal diet according to the targeted hazard quotient and hazard index (THQ and HI) (values < 1). In addition, and as a novel aspect for seaweeds, Selenium Health Benefit Values (Se-HBV) were determined and found to have positive values. Seaweed can be used as an absorber of inorganic metals for removing contamination in coastal waters. The results are a precursor to further research regarding the efficiency and rate at which seaweeds can sequester metal contamination in water. In addition, management techniques need to be developed thereby to control the contaminant inputs.

Assessment of acute toxicity and developmental transformation impacts of polyethylene microbead exposure on larval daggerblade grass shrimp (Palaemon pugio)

Due to the ubiquity of microplastic contamination in coastal waters, there is potential for adverse impacts to organism development. One organism of interest is the daggerblade grass shrimp, Palaemon pugio, an ecologically important species in estuaries along the east coast of North America. We exposed larval grass shrimp to virgin polyethylene microbeads (35 and 58 µm) at a high (0.375 and 1.95 mg/L), medium (0.0375 and 0.195 mg/L), and a low concentration (0.00375 and 0.0195 mg/L), respectively for 23 days to assess mortality, transformation time from larval to juvenile stage, and weight. Average percent mortality was 3.7 to 4.8 times higher in the experimental treatments compared to controls. The greatest proportion of mortality was observed in the first 11 days. Median time for transformation ranged from 20.2 to 20.8 days. Shrimp exposed to the 35 µm beads in the high treatment (20.2 days) transformed significantly faster than the control shrimp (20.8 days). Although development was not delayed and size of the shrimp did not differ, the acute toxicity of microplastics on grass shrimp is a concern due to their role in energy cycling within tidal-creeks. These findings suggest potential population and community level effects following microplastic exposure.

Spatial and Temporal Pattern of Norovirus Dispersal in an Oyster Growing Region in the Northeast Pacific.

Contamination of Pacific oysters, Crassostrea gigas, by human norovirus (HuNoV) is a major constraint to sustainable shellfish farming in coastal waters of the Northeast Pacific. HuNoV is not a marine virus and must originate from a human source. A barrier to effective management is a paucity of data regarding HuNoV dispersal in the marine environment. The main objective of this study was to identify the spatial distribution and persistence of HuNoV in an active shellfish farming region in the Northeast Pacific. Market-size C. gigas were sequentially deployed for two-week intervals at 12 sites during the 2020 winter risk period from January to April. Detection of HuNoV quantification was performed by reverse transcription real-time PCR (RTqPCR) according to method ISO 15216-1:2017, with modifications. RTqPCR did not detect GI HuNoV. The estimated prevalence of GII HuNoV in oyster digestive tissue was 0.8 ± 0.2%. Spatiotemporal analysis revealed that contamination of oysters with GII HuNoV changed through time and space during the surveillance period. A single cluster of oysters contaminated with GII.2 HuNoV was detected in a small craft harbor on 23 April. There was no significant increase in the proportion of positive pools in the next nearest sampling station, indicating that HuNoV is likely to disperse less than 7 km from this non-point source of contamination. Results from this study indicate that HuNoV contamination of coastal waters from non-point sources, such as small craft harbors and urban settings, can pose a significant localised risk to shellfish farming operations in the region.

Combined integral and particle model for describing the dispersion, dilution, terminal layer formation and influence area from a point source discharge into a water body

Contamination of coastal water is a persistent threat to ecosystems around the world. In this study, a novel model for describing the dispersion, dilution, terminal layer formation and influence area from a point source discharge into a water body is presented and compared with field measured data. The model is a Combined Integral and Particle model (CIPMO). In the initial stage, the motion, dispersion and dilution of a buoyant jet are calculated. The output from the buoyant jet model is then coupled with a Lagrangian Advection and Diffusion model describing the far-field. CIPMO ensures that both the near- and far-field processes are adequately resolved. The model either uses empirical data or collects environmental forcing data from open source hydrodynamic models with high spatial and temporal resolution. The method for coupling the near-field buoyant jet and the particle tracking model is described and the output is discussed. The model shows good results when compared with measurements from a field study.

Sources of Low Level Human Fecal Markers in Recreational Waters of Two Santa Barbara, CA Beaches: Roles of WWTP Outfalls and Swimmers

Worldwide, fecal indicator bacteria (FIB) evidence coastal water contamination for which sources are unknown. Here, for two FIB-impacted Santa Barbara recreational beaches, hypothesized fecal sources were investigated over three dry seasons (summers) using nearly 2000 field samples of water (ocean, creek, groundwater), sand, sediments, effluent and fecal sources. In years 1 and 2, gull and dog feces were identified as the probable main FIB sources to surf zone waters, yet HF183 human fecal markers were consistently detected. Determining HF183 sources was therefore prioritized, via year 3 sub-studies. In lower watersheds, human and dog wastes were mobilized by small storms into creeks, but no storm drain outfalls or creeks discharged into surf zones. Beach area bathrooms, sewers, and a septic system were not sources: dye tracing discounted hydraulic connections, and shallow groundwater was uncontaminated. Sediments from coastal creeks and downstream scour ponds, nearshore marine sediments, and sands from inter- and supratidal zones contained neither HF183 nor pathogens. Two nearby wastewater treatment plant (WWTP) outfalls discharged HF183 into plumes that were either deep or distant with uncertain onshore transport. Regardless, local sources were evidenced, as surf zone HF183 detection rates mostly exceeded those offshore and nearshore (around boat anchorages). The presence of swimmers was associated with surf zone HF183, as swimmer counts (on weekdays, holidays, weekends, and during races) significantly correlated (p<0.05, n = 196) to HF183 detections. Besides comprehensively assessing all possible fecal sources, this study provides new explanations of chronic low-level human markers in recreational beach surf zones, suggesting likely lowest achievable HF183 thresholds.

Assessing the in situ bacterial diversity and composition at anthropogenically active sites using the environmental DNA (eDNA)

In this study, we identified the in situ bacterial groups and their community structure in coastal waters influenced by anthropogenic inputs. The use of environmental DNA (eDNA) and high throughput sequencing (HTS) were employed to derive accurate and reliable information on bacterial abundance. The V3 and V4 hypervariable regions of the 16S rRNA gene were amplified and the sequences were clustered into operational taxonomic units to analyze the site-specific variations in community composition. The percentage composition within the bacterial orders varied significantly among nearshore anthropogenic hotspots and offshore (5 km) samples. The microbial network constructed taking the bacterial abundance as nodes displayed strong positive and negative correlations within the bacterial families. Overall, the use of eDNA coupled with HTS is an incredible means for monitoring and assessing the abundance of bacterial communities and also serves as a biomonitoring tool to understand the degree of anthropogenic contamination in coastal waters.

Expanded polystyrene microplastic is more cytotoxic to seastar coelomocytes than its nonexpanded counterpart: A comparative analysis

Microplastics (MPs) are established contaminants of coastal ecosystem. Present investigation is aimed to assess comparative toxicity of polystyrene microplastic (PS-MP) and expanded polystyrene microplastic (EPS-MP) in the coelomocytes of Astropecten indicus, a common seastar of Digha coast of Bay of Bengal, India. Coastal water of Digha, a tourist spot of attraction, bears the ecotoxicological risk of contamination by various agents including expanded and nonexpanded microplastics of industrial origin. Coelomocytes of seastar perform multiple physiological functions including pathogen engulfment, cytotoxicity and respiratory gas exchange and considered as immunoeffector cells in echinoderms. We report an adverse shift in total count, phagocytic response, cytotoxicity and oxidative potential of the coelomocytes of A. indicus under the exposures of 0.5 and 1mgL−1 PS-MP and EPS-MP for 7 and 14 d. Experimental data suggested a higher level of cytotoxicity of EPS-MP in coelomocytes in comparison to that of PS-MP. Seastar is considered as a keystone species, which plays an important role in maintaining the functional homeostasis of coastal ecosystem. Unrestricted contamination of coastal water by MPs may lead to a persistent immunophysiological stress in seastar. Experimental endpoints may be considered as effective monitoring tool to assess ecotoxicity of MPs in seastar and alike organisms sharing the same habitat.

Scenarios of intermittent E. coli contamination from sewer overflows to shellfish growing waters: The Dart Estuary case study

Sewage overflows (SOs) and Combined Sewer Overflows (CSOs) significantly contribute to the bacterial contamination of coastal waters, which is of especial concern for aquaculture, a growing industry worldwide. Hydrodynamic and water quality models were used to investigate impacts of CSO discharge frequency and duration, river discharge and tides on Escherichia coli levels at shellfish farming sites in the Dart Estuary (UK), being the employed methodology generally applicable. High E. coli contamination occurred during neap tides and high river discharges due to higher retention and lower bacterial decay. Synchronicity of CSO spills affected the duration of the pollution episodes rather than peak concentrations, more influenced by discharges of the neighbouring CSOs. During peak discharges, E. coli concentrations could be 10 times higher than during average flows. CSO spills were more frequent when rainfall was >20 mm. Model outputs combined with rainfall forecasts can indicate microbiological contamination risk in the aquaculture sites.

RNAseq Reveals Sensitive, Concentration-Dependent Transcriptional Markers of Copper in Mytilus californianus Larvae and Adults

Copper contamination of coastal waters is a long-standing problem in many regions. Copper water quality criteria in marine waters is often determined with bivalve embryo-larval toxicity tests which measure survival and normal development as endpoints. Gene expression data is increasingly incorporated into such assays as a complementary and sensitive marker of contaminant exposure or toxicity. Here we measured the impacts of copper on Mytilus californianus larval transcriptional profiles, and identified sensitive biomarkers of copper exposure. Key functional categories that were identified among these genes include biomineralization/shell formation, metal binding, and development. Finally, we compared the transcriptional response of larvae to that of adult gill tissue, and show in both datasets that patterns of declining transcript expression occur at lower copper concentrations than those required to induce increases in transcript expression, suggesting that down-regulated genes serve as the most sensitive marker of copper exposure.

Screening of 484 trace organic contaminants in coastal waters around the Liaodong Peninsula, China: Occurrence, distribution, and ecological risk

Human activities such as agriculture, aquaculture, and industry can lead to the pollution of coastal waters by trace organic contaminants (TrOCs), and the TrOCs can pose a threat to marine ecosystems. Therefore, it is essential to investigate the occurrence, distribution, and ecological risk of the TrOCs in coastal waters. Previous studies adopting conventional analytical methods have focused on a limited number of targets. Herein, a comprehensive and systematic determination was undertaken to target 484 TrOCs in the waters around the Liaodong Peninsula, China. Eighty-six TrOCs were detected at concentrations of up to 350 ng L−1, and 25 TrOCs were detected at a frequency of >50%. Pesticides were the predominant pollutants, occurring at high concentrations with large detection frequencies. Ecological risks were assessed for single pollutants and mixtures based on the risk quotient and concentration addition modeling, respectively. The detected pesticides posed relatively high risk to aquatic organisms, while pharmaceuticals, consumer products, and other pollutants posed little or no risk. TrOC mixtures posed extremely high risk to aquatic organisms, which represented a significant threat to the marine environment and local communities. The results described here provide useful information that can inform China’s “Action Plan for Prevention and Control of Water Pollution”.

Application of Water Quality Index and Multivariate Statistical Analysis for Assessing Coastal Water Quality

Contamination of coastal water by seawater is a global phenomenon, which deteriorates the water quality. The present study aims to assess the suitability of coastal water for drinking and irrigation purposes with regard to seawater contamination. Conventional hydrochemical data have been utilized in conjunction with mathematical and statistical methods. Sixty groundwater and nine surface water samples were collected from the eastern coastal plains of Odisha, India and were analyzed for various physico-chemical parameters. A significant influence of seawater on water quality has been observed. Additionally, ion-exchange process has been identified to play a vital role in controlling the water chemistry. Application of hierarchical cluster analysis on water quality data produces two clusters of samples (C-1 and C-2) that are well-explained by the factors of principal component analysis. Higher dissolved salt contents in a majority of samples in the C-1 cluster have resulted in higher water quality indices that make them unsuitable for drinking purposes. Further, their placement in the Wilcox and USSLS diagrams indicated that these samples are even unsuitable for irrigation purposes. The C-2 cluster comprises 38% of water samples, which can be utilized for both drinking and irrigation purposes. The spatial distribution of water quality shows that the drinkable and irrigational water is mainly confined to a few patches in the area. These patches may be utilized for supplying the drinking water to the coastal population.