No abstract

The accumulation levels of elements (Al, As, Li, Mg, Mn, S, Si, Ti, and V) in the soft tissue of mussels (Mytilus galloprovincialis), collected monthly in 2016, from Junuary to December, from sampling sites of the mussel farming facilities installed in the coastal areas of Al Hoceima, were investigated. The studied element levels were determined by using Inductively Coupled Plasma -Optical Emission Spectrometry (ICP-OES 720-ES). Descending order of the average element concentrations in soft tissue of M. galloprovincialis was S > Mg > Si> Al > Mn > Ti > As >V > Li. Element contents (Al, As, Mg, S and V) in tissue of mussels were significantly different (P < 0.05) between seasons, being highest in winter and lowest in summer. Strong correlations were observed between studied elements and chlorophyll a, indicating the importance of food for metal bioaccumulation in mussels in this period of the season. The observed strong correlations for metal levels in tissues of mussels can be explained by their common sources, which are associated with anthropogenic effects. The detected seasonal variations of investigated element concentrations in soft tissues of M. galloprovincialis could be attributed to physicochemical parameters such as temperature, salinity, dissolved oxygen, nutrients and food availability, as well as the biological status of the mussel. This study may provide basic information for detecting the current pollution status of investigated elements in Al Hoceima coasts from the Moroccan Mediterranean Sea using M. galloprovincialis as biological indicators.

No abstract

This study analyses the seasonal distribution in the superficial sediments of the Marchica watershed of trace and major elements, grain size, and total organic carbon. Samples were taken during the wet and dry seasons of 2018 in the mainstream valleys carrying the discharges to the Marchica Lagoon. Ecotoxicological indices (Enrichment Factor, Contamination Factor, Pollution-Load Index) and sedimen-quality guidelines were used to evaluate the ecotoxicological risk. The results revealed during both wet and dry seasons contamination by lead in all stream valleys. The northwest stream valley, characterized by some industrial activities, and the stream valley crossing the abandoned mine were the most polluted by zinc and copper. Minimal pollution for Cr, Co, and Ba was found during both the wet and dry seasons. Despite the restoration actions achieved around the Ramsar site of Marchica lagoon during the last decades, the watershed continues to have a negative impact on this ecosystem. Therefore, an environmental management strategy isnecessary, taking into account the rehabilitation of the abandoned mining sites, the rational use of pesticides and fertilizers in agriculture, and the environmental responsibility of industrial companies, especially those installed before the implementation of the national law on environmental impact studies.

Marchica Lagoon, a Ramsar site on the Mediterranean coast of Morocco, is experiencing the impacts of watershed pollution, which includes pollutants from the domestic, agricultural, industrial, and mining sectors. Restoration actions were undertaken around this lagoon during the last decade in order to protect its ecological value and to develop tourist activity. To conserve the biodiversity in the lagoon, it is important to assess the environmental state of this ecosystem. This study aims to evaluate the ecotoxicological state of sediments through the post restoration characterization of the trace elements Pb, Cu, Zn, Cr, Co, and Ba, as well as their correlation to the major elements, grain size, and total organic carbon, sampled during two campaigns (the wet and dry seasons of 2018) across a sampling network of thirteen stations. Multivariate analysis and ecotoxicological risk assessment of the trace elements using the sediment quality guidelines and five pollution indices (geoaccumulation index (Igeo), enrichment factor (EF), contamination factor (CF), pollution-load index (PLI), and mean effect range median quotient (m-ERM-Q)) revealed contamination of the lagoon by Pb, Zn, and Cu, and minimal pollution by Cr, Co, and Ba. The distribution of the biological-risk index reveals that four zones of the lagoon may present a high probability of toxicity, thus constituting potential risk areas for aquatic organisms: during the wet season, the area in the northwestern sandbar border, the southwest eutrophication zone, and the mouth of the stream valley conveying industrial discharges; and during dry season, the northwestern eutrophication zone. Despite the restoration actions achieved around the lagoon, the lead, zinc, and copper concentrations increased, and their variation was significant between group stations. The biodiversity conservation of Marchica Lagoon requires continuous monitoring and assessment, as well as the implementation of an integrated management plan with restoration actions, not only around the lagoon, but also at its watershed level.