Assessment of Organic and Inorganic Pollutants along the Qatari Coast

The Qatari marine environment is endangered due to high industrial expansion and anthropogenic pressure over the last few decades. The presence of common contaminants such as total petroleum hydrocarbons (TPHs) and polycyclic aromatic hydrocarbons (PAHs) is a threat to the marine environment. The aim of this study is to determine the environmental threats and risks posed by organic contaminants to Qatar’s marine environment using pearl oyster ‘Pinctada Radiata’ as the indicator study organism. The samples (marine sediment, seawater, and oysters) were collected four times within two years in different seasons from the four sites (Simaisma, Al Khor, Umm Bab, and Al Wakra), on March 2017, December 2017, May 2018, and November 2018. A total of 144 samples were analyzed, 48 samples of seawater, 48 samples of sediment and 48 samples of oysters. Levels of organic contaminants (TPHs and PAHs) were quantified in seawater, marine sediment and oyster tissues (P. radiata). In addition, the TOC and particle sizes were measured in abiotic matrices as well as the temperature, salinity, and pH of seawater in the study areas. Overall, the organic contaminants (TPHs and PAHs) were more readily detected in oyster tissue samples than marine sediment and seawater samples collected from the same areas. The surface seawater samples showed negligible levels of PAHs, while TPHs were ranged from 1.164 to 271.77 μg/L. The concentration of TPHs and PAHs in surface marine sediment were ranged between (75.02 -1751.82) and (4.25 - 36.73) μg/kg dry weight respectively. In oyster tissue samples, the level of TPHs was ranged from 633.33 to 6666.67 μg/kg dry weight, with the highest concentrations measured in Simaisma, while PAHs concentration showed an extreme variation from 25.90 to 2244.03μg/kg dry weight. The present study could, however, provide useful background information for further investigations to understand the presence of organic contaminants in Qatar’s marine environment.

Environmental magnetism and application in the continental shelf sediments of India

The NPRP9-394-1-090 project “Pearl Oyster: from national icon to guardian of Qatar's marine environment” had as main aim to develop and apply an integrated suite of chemical and biological methods as early warning tools to assess the “health” of Qatar’s marine environment. The central theme consisted in an investigative monitoring program around the use of the pearl oyster, Pictada imbricata radiata, as a sentinel or guardian species. We have characterized the main environmental contaminants of concern at a selected number of sites around the Qatari coast (UmmBab, Al Khor, Al Wakra and Simaisma), during 2 years, in summer and winter. Potential ecological effects of contaminants (targeted and untargeted) were investigated at different biological organization levels (gene, chromosome, cell, individual, population), through a multidisciplinary approach, using classical and genotoxicological endpoints, integrative histopathology and transcriptomic responses to the different environmental stresses. To our knowledge, this is the first time an integrated approach connecting all these disciplines has been applied in the Qatari marine environment. We present here the main results, of this 3 years project, obtained in all different disciplinary approaches. The results of this project will leave a legacy of resources for future Qatari researchers, including an open access transcriptome data base and the first description of common pathologies observed in the pearl oyster P. i. radiata. Moreover, they will also represent a sound science-based baseline data essential for conservation and management planning, by integration of the data from all the different disciplines applied in the project to assess the potential ecological effects of contaminants at different biological levels.

First Impact Assessment of Genotoxic Components in the Qatari Marine Environment

Organic and inorganic human-induced contamination of Posidonia oceanica meadows

The coastal areas and the adjacent islands are the hotspots of human economic and social activities, including urbanization, industrialization, and agricultural practices, which have profound impacts on the ecological environment of the coastal environment. Antibiotic resistance genes （ARGs）, as emerging contaminants, have become hot topics in water ecological security and public concern. However, the profiles of antibiotic resistome in the costal water remain largely unknown, impeding resistome risk assessment associated with coastal environments. In this study, the high-throughput quantitative PCR technique was used to investigate the abundance and distribution of ARGs in the coastal environment of Xiamen City. Combined with the 16S rDNA gene amplicon sequencing method, the structure and composition of the microbial community in a water environment were investigated, and the influencing factors and associated mechanism of ARGs in seawater were deeply explained. The results of this study showed that a total of 187 ARGs were detected in the coastal water environment, and the abundance level was up to 1.29×1010 copies·L-1. Multidrug resistance, aminoglycosides, and β lactamase resistance genes were the three main classes of antibiotic resistance genes in the water environment of the Xiamen coastal zone. On the whole, the profile of ARGs was of high abundance, great diversity, and common co-existence, and the coastal water environment was an important hot area and reservoir for antibiotic resistance genes. Twenty-two microbes, including Nautella, Candidatus, Tenacibaculum, Rubripirellula, and Woeseia, were potential carriers of the corresponding 16 antibiotic resistance genes. The mobile genetic elements （MGEs） and microbial community structure accounted for 93.9% of the variation in environmental resistance genes in water. Therefore, microbial community and its mobile genetic elements were the most important driving forces for the occurrence and evolution of ARGs in coastal waters. Based on the results, it is implied that the environmental antibiotic resistance genes in the waters near Xiamen Island have potential risks to water ecological security and human health and highlight the necessity for comprehensive surveillance of ARGs associated with microbial contamination in the coastal aquatic environment.

Arabian Gulf oyster reefs, dominated by the pearl oyster Pinctada radiata, function simultaneously as ecological keystones and cultural touchstones. Rapid coastal urbanization and escalating pollution now threaten reef integrity. This systematic review of 1400 publications distilled 42 rigorously screened studies (3%) that document reef distribution, ecological roles, contaminant burdens, and socio-historical context. The results show that reef structures stabilize sediments, enhance water clarity through exceptional filtration rates, and furnish nursery habitats for commercially important fisheries, while heavy metal bioaccumulation in oyster tissues indicates widespread coastal contamination. The Gulf’s economy and identity were historically anchored in pearling; contemporary restoration initiatives already deploying dozens of sustainable reef modules across hundreds of traditional dive sites seek to revive this heritage and bolster ecological resilience. Persistent knowledge gaps include comprehensive spatial mapping, the effects of climate change and pollutant interactions, and long-term restoration success in hypersaline conditions. An integrated management framework that couples stringent monitoring, pollution mitigation, adaptive restoration, and heritage-centered community engagement is essential to safeguard Gulf oyster ecosystems and the cultural narratives entwined with them.

Studies on the west coast of North America suggest that nearshore oceanographic conditions can have important effects on rocky intertidal community structure and dynamics. Specifically, upwelling-dependent processes in coastal waters can affect both top-down and bottom-up processes on adjacent rocky shores. As a first step in testing the prediction that similar linkages occur elsewhere, we investigated the effects and rates of predation, grazing, and recruitment on rocky intertidal community dynamics at upwelling and non-upwelling sites on the South Island of New Zealand. Comparative-experimental studies were done at each of two sites on both the east and west coasts of the South Island. We quantified benthic community structure, maximal wave force, nearshore sea-surface temperature, air temperature at low tide, nutrient concentrations, survival of mussels, rates and effects of predation, rates and effects of limpet grazing, recruitment of mussels and barnacles, and RNA:DNA ratios (a growth index) of mussels. Overall, zonation patterns were similar on the upper shore on both coasts: barnacles (Chamaesipho columna) dominated the high zone, and mussels (Mytilus galloprovincialis) the middle zone. In the low zone, however, community structure differed markedly between coasts. East-coast low-zone communities were dominated by mussels with a moderate canopy of kelp, primarily Durvillea spp., while mussels were largely absent from west-coast low zones. Food webs were similar on the different coasts and included predaceous whelks, sea stars, oystercatchers, and herbivorous limpets. Field experiments showed that only sea stars and limpets had strong effects at west-coast sites, and only limpets had strong effects at east-coast sites. The sea star Stichaster australis, previously identified as a keystone species on the west coast of the North Island, was common and important on the west coast of the South Island but was absent from the east coast. Physical conditions (wave forces, low-tide air temperature) were comparable on the two coasts, suggesting that other factors caused the differences in low-zone community structure. Experiments and observations indicated that predation, grazing, prey recruitment, and mussel growth were greater on the west than on the east coast. While some between-coast contrasts in community dynamics could emanate from differences in species composition (e.g., the absence of S. australis from the east coast), the higher west-coast rates of most of the ecological processes studied suggest that between-coast differences may also depend on other factors. Among the alternatives, a difference in nearshore oceanographic conditions on the opposite coasts of the South Island seems most likely. Prior oceanographic research, and our onshore measurements of sea-surface temperature and nutrients indicate that summer upwelling may be relatively frequent on the west coast and rare on the east coast. While detailed oceanographic studies synchronized with benthic studies in nearshore coastal environments are needed to evaluate this hypothesis, present evidence is consistent with the view that rocky intertidal community structure and dynamics vary with large-scale oceanographic conditions in nearshore coastal environments around New Zealand.

Combining multiple methods for provenance discrimination based on rare earth element geochemistry in lake sediment

Samples collected in January and June 1994 from the Point Loma Wastewater Treatment Plant (PLWTP) effluent, Tijuana River runoff, and microlayer, sediment trap, and surface sediment at several locations adjacent to the PLWTP outfall, mouth of the Tijuana River, and San Diego Bay were analyzed in an attempt to identify and assess the sources of hydrocarbon inputs into the coastal marine environment off San Diego. Several compositional indices of polycyclic aromatic hydrocarbons (PAHs), for example, alkyl homologue distributions, parent compound distributions, and other individual PAH ratios, were used to identify the sources of PAHs. Partially due to the decline of PAH emission from the PLWTP outfall, PAHs found in the sea surface microlayer, sediments, and water column particulates near the PLWTP outfall were predominantly derived from nonpoint sources. The sea microlayer near the mouth of the Tijuana River appeared to accumulate enhanced amounts of PAHs and total organic carbon and total nitrogen, probably discharged from the river, although they were in extremely low abundance in the sediments at the same location. Surprisingly, PAHs detected in the microlayer and sediments in San Diego Bay were mainly derived from combustion sources rather than oil spills, despite the heavy shipping activities in the area.

Coastal environments, ecologically fragile zones, are subjected to great human pressures, particularly, xenobiotic pollutants such as microplastics (MPs) and trace metals. Yet, the impact of anthropogenic intervention on the spatial patterns of MPs in different coastal environmental compartments of Qingdao, a city located in the west Yellow Sea, is still unclear. Therefore, the spatial distribution, characteristics, and diversity of MPs (≥ 50 µm) in seawater, sediment, and sand samples collected from 10 zones intervened by different anthropogenic activities in Qingdao coastal environment were investigated. The abundance of MPs was 93.1 ± 63.5 items/m3 in seawater, which was 4577 ± 2902 items/kg in sediments and 3602 ± 1708 items/kg in the beach sands. A spatial analysis indicated that the distribution characteristics of MPs, including abundance, color, and type, greatly varied among the zones with different extent of human activities. The highest abundance of MPs in the seawater was detected in the abandoned aquafarm, followed by harbors, beaches, estuary, sewage discharge areas, operational aquafarm, and rural areas, whereas the highest MP abundance in the sediments followed the order of harbor, sewage discharge, estuary, abandoned aquafarm, beaches, rural area, and operational aquafarm. The highest MP abundance in the scenic and recreational beach sands was, respectively, in the intertidal and supratidal zone. The transparent chlorinated polyethylene fragments with the relatively small size of 50–100 μm were the dominant MPs in the coastal environment. The higher physicochemical characteristic diversity in terms of size, color, shape, and type of MPs in the aquafarms, harbors, and recreational beach than those of the other zones, illustrated the higher complexity and diversity of MP pollution sources in these zones. These results jointly indicated that aquaculture, navigation, and tourism mainly determined MP spatial distribution patterns in the coastal environment of Qingdao. These results also extend the understanding of the inventory and fate of MPs in coastal environment, thus providing important data to establish effective strategies for abating MP pollution in marine ecosystems.

The twenty‐first century is confronted with the consequences of enormous amounts of global emerging plastic waste resulting from an excessive use of plastic, which has been imparting several negative impacts on the environment and human health. Moreover, some novel variants have also been reported in some coastal environments, so far, as a result of mixing of plastic waste with various other matrices. As a result, the problem of various forms of plastic waste within the marine ecosystem has emerged as a major concern in recent years. The current review is focused on the detrimental implications of various emerging and novel plastic variants, with an emphasis on coastal and marine environments. This review highlights the fate and transportation patterns of plastic waste, along with the contemporary examples of its implications on marine biota. Additionally, this work also examines the impacts of marine plastic waste on the environment. The review further highlights the importance of circular economy of plastic waste for sustainability. Then in the end, the growing anxieties about the impacts of plastic waste on coastal as well as marine environment, along with the strategies for reducing its impacts on ecological sustainability are discussed.This article is categorized under: Climate and Environment > Circular Economy

Thirty-five surface sediment samples from the Indian continental shelf were recovered offshore from the mouths of the major rivers (Brahmaputra, Ganges, Narmada, Tapti, Godavari, Krishna and Cauvery) discharging into the coastal region of both east and west coasts were analysed using inductively coupled plasma atomic emission spectroscopy for selected major (i.e. Al, Ca, Fe, K, Ti, Mg and Na) and trace elements (e.g. Ba, Co, Cr, Cu, Ga, Ni, P and V), after total dissolution. The main objectives are to understand the processes controlling major and trace elements in the surface sediments and to identify natural and anthropogenic sources in the coastal environment using statistically regressed elemental concentrations to establish regional baseline levels. Metal enrichments observed close to the major urban areas in the east and west coasts are associated with the industrialised activities areas rich in Cu and Co in both the east and west coast sediments. Normalisation of metals to Al indicated that high enrichment factors are in the order of Ca > Ti > or = Fe > Na > Mg > Co > Cu > Ga > V > Ba except K and P depletion. This indicated that the characteristic of estuarine sediment showed higher level along the west coast of India, which was reflected in the coastal sediments as similar to the source of its origin from the riverine composition and its abundances.

Spatial analysis of Protected Areas of the coastal/marine environment of Brazil

Differential responses in the biotransformation systems of the oyster Crassostrea gasar (Adanson, 1757) elicited by pyrene and fluorene: molecular, biochemical and histological approach - Part I