Spatial-temporal assessment of Norovirus contamination in mussels from Cherrat estuary, Morocco, by real-time Reverse Transcription-Polymerase Chain Reaction

Mussels filter large amounts of water to extract nutrients; therefore, they can concentrate and accumulate in their tissues infectious agents, and vectors of enteric diseases. The aim of this study was to assess mussel contamination by Norovirus genogroups I and II  in the Cherrat estuary to determine the public health risk linked to their consumption. Mussels (Mytilus galloprovincialis) were collected (n=52 samples; 12 mussels/sample) at four sites (S1 and S2 located on the right rocky bank / S3 and S4, located on the rocky left bank) in the Cherrat estuary (Casa-Settat region), Morocco, during 13 months, from March 2019 to March 2020. Norovirus was detected and quantified by real-time Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Norovirus genogroups I and II were detected in 17.30% and 94.23% of mussel samples, respectively. Contamination by Norovirus (genogroups I and II) was not correlated with seasonal factors (month and rainfall), and Norovirus prevalence was comparable among the four sampling sites. Consumption of raw or undercooked mussels contaminated with Norovirus can cause gastroenteritis, which represents a potential risk to human health. The present study would be helpful to control and manage the potential risk to the public health of the Moroccan population due to the degradation of water quality continuously impacted by runoff, the urban wastewater treatment system malfunctions, and overflows from nearby sewage systems.

Spatial and seasonal fluctuations of Ichthyoplankton assemblage in the Mediterranean coast of Morocco (Southwestern Alboran Sea)

Ichthyoplankton represent the first life stages of fish. The study of ichthyoplankton is crucial to understanding marine ecosystems and plays an important role in the management and durability of fisheries resources. During March and October of 2019, two oceanographic ichthyoplankton surveys were conducted in the Mediterranean Sea of Morocco from Tanger to Saadia by studying the horizontal structure of the ichthyoplankton species assemblage and its relation to environmental parameters. The average surface water temperature was (15.8°C in spring and 16.4°C in autumn). The fish eggs and larvae were more abundant in March than in October (21268 eggs/10m² and 14084 larvae/10m² in spring and 10094 eggs/10m² and 13796 larvae/10m²). In both seasons, fish eggs from the families Sternoptychidae and Sparidae were dominant (10101 eggs/10m² and 7527 eggs/10m² in spring and 4422 eggs/10m² and 3928 eggs/10m² in fall, respectively). However, Myctophidae larvae were the most abundant in the study area, reaching 7601 larvae/10m² in spring and 11021 larvae/10m² in autumn. The environmental parameters: temperature, salinity and chlorophyll-a (surface) seem to directly influence the spatial distribution of ichtyoplancton. On the other hand, it seems that predation by jellyfish (Pelagia noctiluca)was a very important factor that added to the factors that influenced the distribution of the species of fish eggs and larvae. This work represents the first survey conducted in the southwestern Alboran Sea, which studies the horizontal structure of the ichthyoplankton species assemblage and its relation to environmental factors in the spring and autumn of 2019

Spatial and temporal variation of faecal pollution indicators (Escherichia coli and faecal streptococci) and physico-chemical parameters at the Oualidia lagoon and its watershed (Morocco)

International audienc

Origin and potential ecological risk assessment of trace elements in the watershed topsoil and coastal sediment of the Oualidia lagoon, Morocco

International audienc