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In Morocco, the marine environment has always been a major occupation for socioeconomic activities (industry, tourism, urbanization, etc.). Thus, this work displays a case study of Taghazout coast in the central Atlantic part of the country, which becomes the center of several development projects, such as the touristic resort Taghazout Bay. In the aim to assess the health status of this coastal ecosystem, a multi-indicator approach based on the response of biomarkers in the wedge clam Donax trunculus was adopted during two years (2016/2017). The undertaken investigations on the response of biomarkers (AChE, GST, MDA, and CAT) in the sentinel species D. trunculus showed an activation of defense mechanisms in this bivalve, which would imply exposure to chemical stress in this ecosystem. The monitoring of seasonal bioaccumulation of cadmium (Cd), lead (Pb), and copper (Cu) by D. trunculus indicates that the bivalves collected have been exposed to these metal sources in the study area. In addition, the correlation study has reported a significant effect of environmental parameters on biomarker response. Overall, the multi-indicator approach has clearly revealed the health status of Taghazout coast registered in a coastal urbanization. [ABSTRACT FROM AUTHOR]

Aims: The present study was aimed to determine the diversity of the halophilic and halotolerant bacteria with hydrolase activities from salterns of the protected ecosystem Khnifiss lagoon (Morocco). Methodology and results: Bacteria were isolated from sediment samples collected at five hypersaline sites on three different growth media supplemented with various concentrations of NaCl. Thirty bacterial isolates were identified using the 16S rDNA sequencing method. Physiological characterization was examined on Columbia agar with different concentrations of NaCl and pH values and incubated at different temperatures. Enzymatic activities were tested in submerged cultures with appropriate substrates. A total of 246 halophilic bacterial isolates from the salines of the protected ecosystem of Khnifiss lagoon in the south of Morocco were able to produce different hydrolases (cellulases, amylases, DNases, lipases and proteases). Furthermore, the majority of the isolates were classified as moderately halophilic bacteria that grew optimally between 5% and 15% of NaCl, and they adapted to other extreme conditions than salt: some cases tolerated a pH range of 4.5 to 9.4, as well as a temperature range of 10 to 50 °C. The 16S rDNA sequencing and phylogenetic analysis results indicated that most of the bacteria isolated from the salt marshes studied belong to the genus Bacillus. Conclusion, significance and impact of study: Phenotypic and phylogenetic characterization of halophilic and halotolerant bacteria isolated from the salines of the protected ecosystem of Khnifiss lagoon has shown great diversity. Screening of hydrolytic enzymes produced by these bacteria suggests that the salines of the Khnifiss lagoon are a rich source of technologically interesting bacteria. [ABSTRACT FROM AUTHOR]

Visual pollution refers to the degradation of landscape aesthetics, manifesting as visible deterioration. On the Agadir coast in Morocco, factors such as urbanization, erosion, marine wracking, litter, sewage, beach driving, and animal waste contribute to this issue, which detracts from coastal scenery. This study employs the coastal scenery evaluation system (CSES) to conduct a scenic assessment of 40 coastal sites, aiming to describe the current state of visual pollution and inform management interventions. The CSES utilizes a checklist comprising 18 physical and 8 human parameters to calculate a scenic evaluation index (D value), which categorizes coastal sites into five classes. These range from Class I — typically undisturbed natural areas with pristine scenic qualities — to Class V — which are degraded natural areas significantly impacted by human activities. The scenic evaluation classified these sites into three classes. Four sites (10 %) were classified as Class III, fifteen (37.5 %) as Class IV, and twenty-one (52.5 %) as Class V. No sites were classified as Classes I or II. The assessments presented here offer a comprehensive overview of the Agadir coastal scenery and establish a baseline for developing strategies to address visual pollution. • Scenic quality of 40 sites along the Agadir coast on the Moroccan Atlantic Coast. • Prevalence of degraded scenic sites classified in lower categories. • Substantial impact of anthropogenic activities on scenic degradation. • Coastal scenery plays a core role in the economic landscape, especially in tourism. • The coastal scenery management plan aimed to reverse scenic degradation. [ABSTRACT FROM AUTHOR]

Background: Agadir city plans to reuse treated wastewater on a large scale to irrigate these green spaces. This study aims to evaluate the risk of intestinal parasites, to which human and animal populations are exposed during the reuse of treated wastewaters. Methods: Over 21 months, wastewater samples were collected in Bensergao and Mzar wastewater treatment plants, in Agadir city, southern Morocco. The occurrences and removal of intestinal parasites were inspected using the modified Bailenger method. Results: The biodiversity of helminths is higher than protozoa, while the protozoa cysts are more abundant and more prevalent. Generally, the highest parasitic loads were recorded during the hot season. For raw waters, the average concentration of protozoa cysts was 173.33 ± 70.81 cysts per L for Bensergao plant and 179.33 ± 129.22 cysts per L for Mzar plant. However, the helminths average concentration was 48.70 ± 39.91 eggs/larvae per L for Bensergao plant and 51.10 ± 31.76 eggs/larvae per L for Mzar plant. The purified water of the Mzar plant does not contain parasites, unlike the Bensergao plant where a small numbers of parasites were detected, included 2.33 ± 1.53 cysts per L for protozoa and 0.45 ± 0.58 eggs/larvae per L for helminths. Conclusions: Considering parasitological risks, the purified waters of Bensergao plant cannot be used without risks to the public health and environment. In contrast, the purified waters and the purified waters disinfected by ultraviolet radiation from the Mzar plant can be used safely to water the green spaces of Agadir city. [ABSTRACT FROM AUTHOR]

Coastal tourism's surge raises concerns for Morocco's Agadir marine environment, notably with Taghazout Bay's impact. Our study assesses Taghazout's health, employing a comprehensive approach. Our study evaluates Taghazout's health, adopting a comprehensive approach covering physicochemical, microbiological aspects, macrobenthic fauna, metal pollution, and biomarkers in D. trunculus mollusks. Seawater quality aligns with Moroccan standards, indicating good bathing water. The intertidal zone hosts ten species, dominated by D. trunculus. Biomarker responses in D. trunculus suggest chemical stress. Land-use maps expose significant changes driven by the Taghazout Bay project, impacting approximately 37.99 % of the landscape. Construction activities notably encroached upon the Arganeraie and the coastal zone, creating a stark contrast from 2003. These findings form a crucial database for future studies, contributing significantly to environmental management and sustainable development, aiding informed decision-making and effective coastal ecosystem preservation strategies. • Seawater Quality at Category A: Providing an Ideal Environment for Tourism • Sparse Benthic Diversity with D. trunculus Dominating the Ecosystem • Biomarker Analysis Indicates a Stress Response in D. trunculus • Informed Environmental Management Practices for Sustainable Coastal Development • Implementing a Comprehensive Coastal Preservation Strategy for Long-Term Impact [ABSTRACT FROM AUTHOR]

Today, the world is increasingly concerned about marine litter and its interaction with marine biodiversity. However, knowledge concerning the fouling organisms associated with marine litter is very limited in many of the world's marine environments. In this survey, we investigated biofouling on different types of marine litter washed up on all the coasts of the central Atlantic of Morocco. The findings revealed 21 fouling species belonging to 9 phyla (Arthropoda, Mollusca, Echinodermata, Annelida, Bryozoa, Porifera, Chlorophyta, Ochrophyta, and Ascomycota). More specifically, frequently observed fouling species include Mytilus galloprovincialis , Balanus laevis , Megabalanus coccopoma , and Pollicipes pollicipes species. Large marine litter items recorded the highest colonization of marine organisms in comparison to small ones. The frequency of occurrence (FO) of the species most commonly fouled on all coasts was Perforatus perforatus (FO = 48.60), followed by Mytilus galloprovincialis (FO = 45.80), Balanus trigonus (FO = 32.05), Balanus laevis (FO = 30.25), Megabalanus coccopoma (FO = 25.25), Bryozoa species (FO = 19.40), Spirobranchus triqueter (FO = 18.18), Lepas pectinata (FO = 14.45), and Pollicipes pollicipes (FO = 13.05). The majority of the species registered in this study are sessile. Substrate coverage by fouling taxa was significantly different between plastic substrate and other types of marine litter. Likewise, this study revealed that the proportion of fouling organisms is higher on rough surfaces. Overall, this research could be crucial to understanding the little-known subject of marine litter and its colonization by marine biota. Given that these marine litters can act as vectors and cause ecological, biogeographical, and conservation issues in the marine environment, minimizing the quantity of anthropogenic litter reaching the Moroccan Atlantic could significantly reduce its accumulation on the sea surface and seabed, thereby reducing the risk of invasion by non-indigenous species. • First study of biofouling on marine litter in the Moroccan Atlantic. • 21 fouling species belonging to 9 phyla were found on the marine litter. • Balanus laevis and Mytilus galloprovincialis were the most prevalent fouling species. • Fouling species on plastics were more frequent than other types of litter. [ABSTRACT FROM AUTHOR]

Mytilus galloprovincialis is common in Morocco's Anza-Taghazout coast, previously polluted by wastewater. Since treatment plants were installed in 2016, no study examined the mussels' reproduction. Our study assessed how wastewater treatment affects the reproduction and growth of the M. galloprovincialis mussel on Moroccan coasts, particularly in the Anza-Taghazout area. We aimed to clarify the impacts of treated effluents on this vital invertebrate. This research explored their reproductive parameters, with samples taken from 2017 to 2018 at Anza, Aourir, and Imouran. Results show all gametic stages with three spawning periods. The gonadal index exceeds 1.4 at all sites, indicating a short resting phase. The sex ratio is balanced in Aourir and Imouran, but Anza has more males. The length-weight relationship showed the b value of 1.56 (R2 = 0.32); 1.71 (R2 = 0.35), and 1.70 (R2 = 0.26) for Anza, Aourir, and Imouran respectively. This suggests a slight negative allometric relationship. The condition index showed a progressive trend, and M. galloprovincialis improved due to enhanced environmental quality after treatment. • Evaluation of the physiological reproductive parameters and condition index of M. galloprovincialis • Presence of all the gametic with three main spawning periods in the year • Gonadal index shows values >1.4 in the studied sites. • Sex ratio is balanced at the level of Aourir and Imouran. • Condition index experienced a progressive trend over the study period. [ABSTRACT FROM AUTHOR]

This study describes the contamination, accumulation, and ecological risk assessment of five trace metals (Cd, Pb, Cu, Zn, and Cr) in sediments of an urbanized beach in the central Atlantic coastline of Morocco. The two-year investigation (2018 and 2019) included six sampling sites along a 6 km coastal reach. In both years, none of the studied trace metals exceeded the background or the sediment quality guidelines (SQGs). The eco-toxicological indices revealed low degree of contamination, unpolluted ecosystem, and low ecological risk of metals. However, Cd exceeded the background value and some SQGs following the increase of anthropogenic activities in 2019. Likewise, it indicated unpolluted to moderately polluted sediment as well as moderate ecological risk. Overall, it is highly recommended to mitigate the avoidable anthropogenic activities (marine litter generation, sewage discharge, intense urbanization, and vehicle traffic on the beach) that lead to the elevation of metal pollution in the study area. • Study of trace metals carried out in surface sediment along an urbanized coast in Morocco • Globally, indices revealed low degree of contamination and no metal pollution in sediments. • Cd recorded moderate levels of both contamination and ecological risk in the second year. • Trace metals levels increased following the intensification of anthropogenic activities. • Sewage discharge, marine litter, and vehicles traffic are potential sources of metals. [ABSTRACT FROM AUTHOR]

This work presents preliminary results about abundance, distribution, characteristics, sources, and fate of microplastics (MPs) in the Central Atlantic Ocean (CAO) of Morocco. The investigation was conducted into three subsections, each characterized by different types of human activities and covering rural, village, and urban areas. MPs were detected in 100 % of the sampling sites. The abundances varied from 0.048 to 3.305 items/m3, with a mean abundance of 0.987 ± 1.081 items/m3. MPs abundance was higher in surface seawater linked to urban areas compared to village and rural areas. The dominant polymer type was polyester (PET-53.8 %) followed by polypropylene (PP-24.36 %), polyamide (PA-7.56 %), polystyrene (PS-6.88 %), polyvinyl chloride (PVC-2.64 %), ethylene vinyl acetate (EVA-2.60 %), polyetherurethane (PUR-1.36 %), and acrylic (AC-0.8 %). Fibers were the most dominant shapes accounting for over 50 %. MPs were mainly smaller than 2 mm in size (71 %) and characterized by colorful aspects. These findings suggested that wastewater treatment plant (WWTP) effluents and anthropogenic activities (industry, tourism, sanitation, and fishing) are the major pollution sources of MPs in the study area. SEM/EDX micrographs showed different weathering degrees and chemical elements adhered to the MPs surface. • Seawater floating microplastic (MPs) quantification from Morocco • MPs ranged from 0.048 to 3.305 items/m3 with high records in sites linked to urban areas. • MPs were mainly smaller than 2 mm in size and fibers were the abundant shape. • The most dominant polymers are polyester (PET) and polypropylene (PP). • SEM/EDX analysis showed weathered MPs with chemical elements on surface. [ABSTRACT FROM AUTHOR]

This study describes the use of D. trunculus as a bioindicator of microplastic (MPs) pollution due to beach urbanization related to the development of the Taghazout Bay tourist resort in Morocco. In six sites located on the coast, MPs densities ranged from 1.75 to 5.93 items per gram of D. trunculus wet weight. MPs contamination was significantly influenced spatiotemporally by the urbanization degree in the area. The shapes found were fibers (90.5%) and fragments (9.5%). The Fourier Transform Infrared Spectroscopy (FTIR) analysis reported two polymers: polyethylene (65%) and polypropylene (35%). MPs colors were dark and light, with a predominance of light blue (23.8%). The species ingested different sizes of MPs, mainly the 0.1 and 0.5 mm fractions. Scanning Electron Microscope coupled with an energy dispersive X-ray analyzer (SEM/EDX) revealed weathered MPs with chemical elements adhered to their surface (Cu, Fe, Mg, S, Cl, etc.). The results of this study recommend the use of D. trunculus as a new bioindicator of MPs pollution following an urban change in the coastal scenery. Also, a sustainable coastal management must be implemented in the study area. [Display omitted] • First use of the clam D. trunculus as a bioindicator of MPs pollution • The shapes reported in D. trunculus are fibers and fragments. • The FTIR analysis revealed two polymers (PE and PP) in D. trunculus. • SEM/EDX recorded weathered MPs and chemical elements on surface. • Coastal management must be implemented in the study area. [ABSTRACT FROM AUTHOR]

This baseline study describes the microplastic (MPs) problem on seven beaches located on Agadir, central Atlantic coast of Morocco. Microplastics abundances (densities) ranged from 7680 MPs/kg to 34,200 MPs/kg above other world beaches. The following shapes were found: fibers, fragments, films, and pellets. Fibers were the dominant typology with a 73%. Polyethylene (PE) was the predominant polymer in all beaches with an average percentage of 59%, followed by Polypropylene (PP - 18%), Polystyrene (PS - 9%), Polyvinyl chloride (PVC - 8%), and Ethylene-vinyl acetate (EVA - 6%). Microplastics abundances presented in this work suggest continuous inputs of plastics of all sizes and types. Also, all observed shapes highlight a combination of sources (primary and secondary). Central Atlantic Moroccan beaches are currently affected by extreme values of MPs that demand urgent interventions to restore environmental quality. • Microplastics were found along 7 beaches of the central Atlantic coast of Morocco. • Microplastics densities ranged from 7680 MPs/kg to 34,200 MPs/kg • Plastic, fibers, fragments, films, and pellets were found. • Fibers were the dominant typology at 73%. • Study area beaches are among the documented mostpolluted beach environments worldwide in terms of MPs abundance. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to assess aquatic environmental quality of Oued Souss (Agadir, Morocco). This estuary has been subjected for a long time to large amounts of sewage discharges and industrial effluents. Since November 2002, no waste outlets have been discharged in this site due to their connection to a wastewater purification plant. Firstly, we have compared metal tolerance of the annelid polychaete (Nereis diversicolor) originating from Oued Souss and a relatively clean site (Oualidia, Morocco). Secondly, we have evaluated with a multi-marker approach (acetylcholinesterase [AChE], glutathione-S-transferases [GSTs], catalase, thiobarbituric acid reactive substances [TBARs]) responses of worms to the pollution gradient. Results have shown that worms from Oued Souss have acquired tolerance to copper and zinc due to a long-term sub-lethal metal exposure and this metal tolerance was maintained in spite of the end of wastewater discharges in this site. Higher catalase, GSTs and TBARs values have been observed in worms from Oued Souss sampled before implantation of wastewater treatment. The multi-marker approach confirms that these worms have been submitted to various contaminants. In contrast, high inhibition in AChE activities measured in worms from Oued Souss could be explained by the continuous agricultural influence of nearest areas. The level of contamination was probably maintained since biomarker values were generally higher in worms from Oued Souss when compared to Oualidia. [Copyright &y& Elsevier]

In order to use purified wastewater on watering green spaces of Agadir city, we conducted this study to assess the bacteriological and physicochemical quality of treated wastewater in Mzar treatment plant. To realize these objectives, we analyzed four types of waters: raw water (RW), decanted water, purified water and purified water treated by the ultraviolet radiation (PWUV). The biologically analyzed parameters are fecal coliforms (FC) and fecal enterococci (FE). The physicochemical parameters are: pH, electrical conductivity, chemical oxygen demand (COD), five-day biological oxygen demand (BOD5) and total suspended solids (TSS). The results showed a high level of bacterial contamination in all types of waters, and the average loads of FC were between 4.71 × 106 CFU/100 mL (RW) and 1.45 × 103 CFU/100 mL (PWUV), while loads of FE were between 2.62 × 105 CFU/100 mL (RW) and 7.92 CFU/100 mL (PWUV). The physicochemical parameters show a pH close to neutrality and a high electrical conductivity (3261 μS/cm) in PWUV. In all stages of wastewater treatment, values of COD, BOD5 and TSS were under the limit values recommended by Moroccan standards. Except for the electrical conductivity and FC, all the studied parameters were under the limit values requested by the Moroccan standards. The microbiological quality of PWUV is unstable, and if these waters are reused, they can affect the microbiological and physicochemical quality of green spaces and groundwater. [ABSTRACT FROM AUTHOR]

Mussels (Mytilus galloprovincialis) are vital to Morocco's artisanal fishermen both nutritionally and economically. This study probed the bioaccumulation of trace metals zinc (Zn), cadmium (Cd), copper (Cu), and lead (Pb) in mussels from three sites north of Agadir: Anza, Aourir, and Imouran. Analyzed using atomic absorption techniques across different seasons, findings indicated variable metal concentrations, with Imouran notably presenting the highest, potentially due to influences from the new wastewater plants of Anza and Aourir. While lead was not detected, cadmium, albeit in lower concentrations, posed potential health concerns upon regular consumption. Individual Mean Bioaccumulation Index (IMBI) demonstrated fluctuations, majorly influenced by Zn, Cd, and Cu levels. These trends in IMBI between 2017 and 2018 for Aourir and Imouran hinted at similar environmental impacts or exposure levels. Despite site differences, Metal Pollution Index (MPI) values consistently pointing to analogous potential toxicity due to metal combinations. Intricate relationships between trace metals and their environmental parameters were evident, with multiple linear regression analysis (MLRA) showcasing differing correlations between variables. These results highlight the nuanced interactions between trace metals and bioaccumulation indices, such as MPI and IMBI. In conclusion, the findings accentuate the imperative of regular coastal water quality checks and effective management strategies to curtail pollutant discharges. [Display omitted] • Wastewater releases threaten mussels, especially with trace metals. • Imouran has the highest metal levels, while Anza is known for pollution. • Cadmium, even in small amounts, is concerning when regularly consuming tainted mussels. • IMBI results vary, influenced by Zn, Cd, and Cu. • MPI values, indicating metal toxicity, are consistent across sites. [ABSTRACT FROM AUTHOR]

Wastewater treatment plants (WWTPs) have been identified as high-load receptors of microplastics (MPs) from different sources. However, the influence of specific treatment stanges requires further research. The main objective of this research was to evaluate the abundance and chemical characteristics of MPs in the sludge of two major wastewater treatment plants in the Agadir metropolis (Central Atlantic of Morocco). The Aourir plant receives urban influents and the inputs of the M'zar facility were urban and industrial. Samples were collected from the sludge matrices after primary settling, clarifying, dewatering, and drying systems. In addition, the effect of seasonality on MP load was assessed. The results showed that a higher abundance was noticed in raw sludge than in dewatered one in Aourir WWTP, while in M'zar WWTP, a very low decrease is noticed in dried sludge compared to raw sludge. The concentration of MPs in the summer season was significantly higher compared to other seasons for Aourir WWTP, while the winter season was higher for M'zar WWTP. Moreover, the most abundant shapes were fibers and the fraction 100–500 μm was the most preponderant. Eleven polymers were identified by ATR-FTIR, being polyester, polyethylene, polypropylene, and polystyrene the most abundant ones. Scanning Electron Microscopy coupled with Energy Dispersive X-ray revealed the visible degradation and fragmentation of MPs from sewage sludge and their ability to adsorb inorganic elements. It was estimated that between 2.2 × 107 and 7.4 × 108 MPs were evacuated with the sludge per day. The obtained findings confirmed that WWTP sludge acts as a vector of MPs with a high level of hazard to various matrices, such as landfills, agricultural soils, and groundwater. Overall, consideration must be given to the regulatory system managing the fate of sewage sludge to mitigate the collateral effects and provide solutions. [Display omitted] • The characterization of Microplastics (MPs) occurring in sewage sludge were assessed. • The dominance of fibers as well as PES, PE, PP, and PS polymers were reported. • SEM/EDX showed that MP surfaces are prone to play the Trojan-horse effect. • The hazard was high making the sludge applications and disposal in landfills risky. • The regulatory system managing the fate of sewage sludge must be reconsidered. [ABSTRACT FROM AUTHOR]

Heavy metals are considered a major threat to aquatic ecosystems, due to their ability to penetrate and accumulate through the food chain, putting marine organisms and the ecosystem at risk. This research presents a case study of the Taghazout coast, located in the central Atlantic of Morocco, which has become the focal point of various development projects, including the Taghazout Bay tourist resort. The study aimed to gain a deeper understanding of the harmful effects of these metals on the reproductive cycle and population dynamics of the bivalve Donax trunculus. The assessment of cadmium (Cd), lead (Pb), and copper (Cu) levels in D. trunculus bivalves and sediment at the research location provides evidence of exposure to these metal sources by these bivalves. The analysis of the reproductive cycle revealed a balanced sex ratio of males to females. The Sexual Maturity Index (SMI) and Condition Index (CI) of the bivalves were found to be significantly influenced by trace elements Pb and Cu, as well as environmental factors like temperature, dissolved oxygen, and salinity. The maturity stages of the gonads were classified into five stages: undifferentiated, developing, mature, spawning, and spent. Two spawning periods were observed aligning with the population dynamics study that identified a bimodal recruitment (early autumn and spring) in D. trunculus. The population was found to have 11 size cohorts, with a maximum length of 37.96 cm, a yearly growth rate of 1.93 cm, and a short lifespan of 1.5 years. The high mortality rate of 3.30 per year was attributed to the presence of trace elements in Taghazout coast. These findings shed light on heavy metal's impact on the population of D. trunculus , revealing that a sole emphasis on its physiological or cellular effects may overlook its larger impact. [Display omitted] • Trace elements (Cd, Pb, and Cu) were present in the Taghazout coast and had bioaccumulated in D. trunculus. • Environmental factors (temp, oxygen, pH, salinity) affected D. trunculus ' reproductive cycle. • The SMI and CI of D. trunculus were significantly influenced by trace metals and environmental factors. • Mortality of 3.30/yr in D. trunculus linked to trace element presence. • Highlighting broader impact of trace element pollution on populations, beyond physiology. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate, in situ, the temporal effects of urban effluent discharge on energy reserves and steroid hormone levels in the intrasedimentary worm Nereis diversicolor. Results have shown no differences in energy reserves (glycogen, lipids) in organisms originating from a contaminated site (Oued Souss) and a comparatively clean site (Oualidia). Both sites are located on the Moroccan Atlantic coast. In contrast, steroid hormone (progesterone, testosterone, and 17beta-estradiol) levels were significantly decreased in animals from Oued Souss. The differences in the responses suggest that organisms from the polluted site have been exposed to endocrine disruptors.