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The aim of the present study is the first to evaluate the ecotoxic state of the marine environment in Anza-Taghazout coasts (Morocco) after installation of two wastewater treatment plants using a natural population of marine bivalves Mytilus galloprovincialis . These coasts are exposed to many discharges generating, thus, different sources of pollutants. These pollutants can modulate the physiological responses of marine bivalves to environmental stress. In this context, a multibiomarker approach consisting of a battery of biomarker evaluation was used to assess the response of these species to stress. In the whole soft tissues of M. galloprovincialis , four biomarkers were evaluated as follows: acetylcholinesterase (AChE), glutathione S-transferase (GST), catalase (Cat), and malondialdehyde activity (MDA). In parallel, physico-chemical parameters were measured in the marine water of Anza-Taghazout within three selected sites: S 1 considered as “hotspot” located at Anza city; S 2 located near of Aourir city; and the third site, S 3 “reference” located in Imouran beach. Our results showed that activities of both glutathione S-transferase and catalase were higher in M. galloprovincialis collected from site S 1 , but high values of malondialdehyde and acetylcholinesterase activities were observed successively at S 3 and S 2 . Application of integrated biomarker response (IBR) index was suitable for classifying the stress response in the M. galloprovincialis but did not allow to evaluate the level of the xenobiotic exposure in the studied sites. The statistical results did not show any significant differences between the three studied sites, and therefore, S 1 has recently become clean due to the installation of two wastewater treatment plants.

Identifying species and updating marine biodiversity is fundamental to understanding the evolution of ecosystems and adopting appropriate management strategies. These ecosystems are threatened by climate change causing species mobility, mortality, etc. An important zoological group in the marine ecosystem, octocoral gorgonians have a wide geographic and bathymetric distribution. However, the knowledge of their presence on the Atlantic West African coasts remains limited. Herein, we note the accurate geographic distribution of two species, Leptogorgia dakarensis (Stiasny, 1936) and Eunicella racemosa (Milne Edwards & Haime, 1857), reporting their northern distributional limits. The gaps in the previous knowledge hypothesis of the oceanic warming effects explaining the northward mobility of these species are discussed here.

Halophilic bacteria are a group of microorganisms living in saline environments and in some cases need the salinity to survive. Furthermore,these bacteria species have the potential for interesting and promising applications. In fact, this is due not only to their ability to adapt to extreme physico-chemical conditions but also because many of them they produce interesting substances for the industry such as extracellular hydrolytic enzymes.The present study aims to isolate and characterize halophilic bacteria producing hydrolase enzymes from twosalinesin Sidi Moussa-Oualidia complex (Morocco) and to screen their potential to produce hydrolase enzymes. In this study, 15 halophilic bacteria were identified and analyzed for their ability to produce extracellular enzymes. The phylogenetic analysis based on 16S rDNA sequencing indicated that the 15 isolated strains belong to the genera Bacillus , Oceanobacillus and Virgibacillus . The study of enzymatic activity revealed that all isolates studied were capable of producing at least one extracellular hydrolytic enzyme of which 9 produced amylase, 6 cellulase, 13 DNase, 11 lipase, and 8 protease. In addition to their ability to produce extracellular hydrolytic enzymes, our isolates have demonstrated their potential adaption to extreme Physico-chemical conditions. These properties could allow them to be used for many industrial applications.

The sustainability of coastal ecosystems, associated fisheries, and environmental quality is increasingly threatened by anthropogenic activities and rapidly expanding urbanization. This study investigated the ecological impacts of increased coastal urbanization on intertidal sediment quality and the biological parameters of the wedge clam Donax trunculus along the central Moroccan Atlantic coast. Between 2018 and 2022, a period characterized by intensified urban activity, total organic matter (TOM) in sediment significantly increased, whereas temperature and pH remained stable. Concurrently, D. trunculus populations experienced notable declines in abundance and biomass, along with marked disruptions in reproductive dynamics. The proportion of sexually mature individuals decreased, while spent individuals and male-biased sex ratios became more prominent. These findings suggest that urbanization-related pressures such as sediment enrichment, pollution, and physical disturbance are exerting measurable stress on this key bioindicator species. The results highlight the need for improved coastal management to mitigate the ecological consequences of rapid urban expansion on coastal sustainability.

Water scarcity has evolved into a pressing global issue, significantly impacting numerous regions worldwide. The use of treated wastewater stands out as a promising solution to this problem. However, the proliferation of various contaminants, primarily Antimicrobial Resistance Genes (ARGs), poses a significant challenge to its safe and sustainable use. In this study, we assessed the composition and abundance of 373 ARGs, corresponding to 31 different classes of antibiotics, in six wastewater treatment plants (WWTP) in Agadir city of Morocco. Influent and effluent samples were collected during the months of February and July in 2020, in addition to samples from the Atlantic Ocean. In total, 223 ARGs were uncovered, highlighting in particular resistance to aminoglycoside, macrolide lincosamide, beta-lactamase, chloramphenicol, sulfonamide, tetracycline, and other antibiotics. The mechanisms of action of these ARGs were mainly antibiotic inactivation, antibiotic target alteration, efflux pump and cellular protection. Mobile genetic elements (MGEs) were detected at high levels their co-occurrence with ARGs highlights their involvement in the acquisition and transmission of ARGs in microbial communities through horizontal gene transfer. While many wastewater treatment methods effectively reduce a large proportion of gene material and pathogens, a substantial fraction of ARGs and other contaminants persist in treated wastewater. This persistence poses potential risks to both human health and the environment, warranting the need of more effective treatment strategies.

The Bay of Agadir, located in Morocco, is of significant economic and ecological value, yet it has faced persistent pollution challenges due to industrial, port, and tourism activities. Despite recent improvements following the implementation of wastewater treatment plants, particularly in the Anza-Imouran sector, knowledge gaps remain regarding the interactions between marine environmental factors and pollution biomarkers in marine organisms. This study examines the influence of environmental factors on the biomarker responses of Mytilus galloprovincialis across three sites (Anza, Aourir, and Imouran) in Agadir Bay, covering the period from January 2017 to December 2018. Principal Component Analysis (PCA) was employed to explore the relationships between four key biomarkers (Catalase (CAT), Glutathione S-transferase (GST), Malondialdehyde (MDA), and Acetylcholinesterase (AChE)), and seven marine environmental factors (water temperature, air temperature, salinity, pH, dissolved oxygen, electrical conductivity, and precipitation). At Anza, Aourir, and Imouran, the first two principal components explained a significant portion of the total variance (80.19%, 78.63%, and 88.60%, respectively). Notable findings include a negative correlation between GST and water temperature ( r  = − 0.57) at Anza. In Aourir, CAT exhibited a positive correlation with rainfall and dissolved oxygen ( r  = 0.78 and r  = 0.41, respectively) but a negative correlation with pH and salinity ( r  = − 0.58 and r  = − 0.44, respectively). Additionally, GST was positively correlated with rainfall ( r  = 0.52), while showing a negative relationship with pH and water temperature ( r  = − 0.40 and r  = − 0.53, respectively). MDA was negatively correlated with salinity ( r  = − 0.59), and AChE was inversely associated with electrical conductivity ( r  = − 0.41). In Imouran, CAT was positively correlated with rainfall ( r  = 0.70), while exhibiting negative correlations with pH, salinity, and electrical conductivity ( r  = − 0.73, r  = − 0.60, and r  = − 0.61, respectively). GST showed a positive correlation with electrical conductivity and salinity ( r  = 0.55 and r  = 0.48), but a negative correlation with water temperature ( r  = − 0.47). MDA was positively correlated with rainfall ( r  = 0.66) and negatively with pH, electrical conductivity, and salinity ( r  = − 0.74, r  = − 0.58, and r  = − 0.67, respectively). These findings highlight the intricate relationship between marine environmental factors and biomarker variability in M. galloprovincialis , emphasizing the importance of further understanding their impact on marine organism health amid ongoing environmental changes. Graphical abstract

SummaryIntroduction: Nosocomial infections associated with a carbapenem-resistant Acinetobacter baumannii (CRAB) are considered as a significant challenge in the Intensive care units’ (ICU) critically ill patients. Lack of new antimicrobial agents to treat infections caused by this multi-drug resistant microorganism reinforces the exploration of novel strategies to encounter and control this infection. Thus, the aim of the study was to evaluate, for the first time, the antibacterial effectiveness of the Lavandula mairei Humbert essential oil (EO) against a CRAB isolated from the hospital environment of the two ICUs.Materials and Methods: Carbapenemase encoding genes were detected by the polymerase chain reactions and sequencing methods. The chemical composition of Lavandula mairei (EO) was determined by a gas chromatography-mass spectrometry analysis, and its antibacterial activity was evaluated by a disk diffusion and broth microdilution methods.Results: The OXA-23 and NDM-1 variants were revealed in the selected strains. Twenty-six compounds were identified in the Lavandula mairei EO, in which carvacrol was the most dominant one (77.32%). All the tested CRAB strains showed a wide sensitivity to the oil, with the inhibition zones’ diameters ranging from 28.67±1.15 mm to 40±2.00 mm, and a bactericidal effect proved by the similarity of minimal inhibitory and bactericidal concentrations values (0.39-3.125 µL/ml).Conclusion:These findings remain very promising for the future use of Lavandula mairei EO as a source of the natural antibacterial agents.

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.

Marine debris is defined as any persistent, manufactured, or processed solid material that is intentionally or unintentionally disposed of or allowed to float into the marine environment. This debris can be of natural or artificial origin and includes a wide variety of materials, such as chemically treated wood. Fine woody debris (FWD), small particles with diameters ranging from 1 to 10 cm, can have natural and anthropogenic origin, which is often overlooked in coastal environments. In this study, we investigated FWD across multiple sites along the central Moroccan Atlantic coastline and identified 2068 FWD elements with an average density of 49.23 ± 38.07 items/m 2 . Site 2, near a river, stood out for its notably greater density, in contrast to the lower densities observed at the other sites. Chemical characterization of the FWD surfaces revealed mechanical abrasions, along with traces of heavy metals (HMs) such as Cu and Ti, plastics (including PS, PP, PE, PA, and PVC), and pharmaceuticals (periciazine, dipyridamole, and canthaxanthin). These findings underscore the role of FWD as a reservoir and transporter of environmental contaminants such as microfibers, and HMs, which can leach into surrounding waters and be taken up by marine organisms. The presence of these contaminants highlights potential disruptions to marine biodiversity and ecological processes, including bioaccumulation and toxicity in aquatic food webs, habitat degradation, and altered nutrient cycling. Moreover, the global significance of these findings lies in their implications for biodiversity management and conservation strategies. Anthropogenic FWD not only represents a source of pollution but also a vector for spreading harmful substances, emphasizing the urgent need for effective management strategies. These include regular monitoring and targeted cleanup efforts to mitigate potential hazards, preserve ecosystem integrity, and enhance recreational experiences in dynamic coastal environments.

In the present study, the antibacterial activity of Thymus leptobotrys and Thymus satureioïdes essential oils was evaluated against nine multidrug resistant Acinetobacter baumannii strains. Besides, their inhibition and eradication effects were investigated, for the first time, against the biofilm form of the tested multidrug resistant bacteria. Gas chromatography–mass spectrometry analysis of the targeted essential oils highlighted the predominance of carvacrol and borneol, respectively. Their antibacterial activity test revealed considerable inhibition zones’ diameters ( p  < 0.05), ranging from 35 ± 1.4 to 43.6 ± 0.5 mm ( Thymus leptobotrys) and from 16.6 ± 1.5 to 22 ± 2.8 mm ( Thymus satureioïdes). Very low minimal inhibitory and bactericidal concentrations ( p  < 0.05) were also noted, varying from 0.78 to 12.5 mg/mL. Four strains out of nine ( Acinetobacter baumannii 6, Acinetobacter baumannii 7, Acinetobacter baumannii 8, Acinetobacter baumannii 9) considered as the strongest biofilm producers by congo red agar and crystal violet methods, were chosen for the evaluation of biofilm inhibition and eradication effects of Thymus leptobotrys and Thymus satureioïdes essential oils. Great biofilm inhibition percentages were noted with 90.20% ( Thymus satureioïdes) and 97.27% ( Thymus leptobotrys) as the highest rates. Forty-eight hours biofilms were more resistant to the essential oils’ action. Low eradication proportions were observed ranging from 0 to 49%. Thus, Thymus leptobotrys and Thymus satureioïdes essential oils could be considered as a natural source of bioactive molecules and used as an alternative approach to prevent biofilm formation of multidrug resistant Acinetobacter baumannii.