Recent pollution records in Sidi Moussa coastal lagoon (western Morocco) inferred from sediment radiometric dating

Heavy metal content and potential ecological risk assessment of sediments from Khnifiss Lagoon National Park (Morocco)

Coastal lagoons are important but sensitive environments, being transitional zones between land and sea. The Khnifiss lagoon is the most important desert wetland in Morocco, but little data have been produced concerning heavy metal geochemistry and enrichments in the sediments. Therefore, 26 surface sediments (15 intertidal and 11 subtidal) and 2 sediment cores were collected in 2016 and analyzed for a selection of heavy metals. The data were processed to assess the degree of contamination and the corresponding potential ecological risk, using several accumulation/enrichment indices, and the singular and multi-metal risk indices. Mean concentrations in the bottom layers of the two cores, dating from a pre-industrial age according to geochronological analysis, were used as the local geochemical background. The resulting values were on the whole lower than those reported for other areas of the northeastern coast of Morocco. Multivariate statistics were also applied to better understand relationships among variables (metals and other geochemical parameters) and to reveal similarities among sample groups. The results showed that, although the lagoon is not yet affected by significant anthropogenic influences, small enrichments can be recognized, especially for Ni and Cd. The cause may be related to the proximity to the main national highway, the vehicles and machinery used in the saltworks located in the area, and the small harbors used principally for fishing. In addition, industrial emissions from the Atlantic coast of Morocco and adjacent countries can be reasonably attributed as additional contributors to the enrichments. In terms of potential ecological risk, Cd shows the greatest impact compared to the other metals investigated.

Understanding the Impacts of Blue Economy Growth on Deep-Sea Ecosystem Services

The deep sea is the vastest environment on Earth and provides many services and goods. Understanding the services and goods of deep-sea ecosystems would enable better resource governance and decision-making. In the present study, we reviewed and assessed deep-sea ecosystems services using the Ma conceptual framework, which incorporates ecosystems services and goods with human welfare. We also analyzed and measured the scientific production between 2012 and 2021 using the Dimension dataset. The bibliometric analysis showed a lack of studies related to deep-sea ecosystem services, which suggest the urgent need to overcome the existing knowledge gap regarding deep-sea components. However, the current knowledge revealed the crucial role that these ecosystems provide to the planet. Furthermore, we highlighted that there are common services and goods, and every ecosystem service feeds into another one. Developing actions and policies based on approaches that combine all deep-sea ecosystems services and goods are needed for the sustainable growth of the deep-sea economy in accordance with the United Nations Development Goal 14: Life Below Water.

LEVELS OF NATURAL AND ANTHROPOGENIC RADIONUCLIDES IN SEDIMENTS OF SOME MOROCCAN COASTAL AREAS AND DOSE ASSESSMENT BASED ON ERICA TOOL

In this work, we considered the concentrations of natural and anthropogenic radionuclides (namely the 40K, 210Pb, 226Ra, 137Cs, 234Th, 228Th and 228Ra) in sediments from Moroccan coast areas by considering estuaries (Sebou and Loukkos) and marine ecosystems (M'diq Bay and three Lagoons: Moulay Bousselham, Sidi Moussa and Oualidia). Sediment samples were analyzed using Gamma spectrometry. The objective was to establish radioactivity levels in Moroccan coastal areas as well as radiological risk assessment by using the ERICA tool. The software allows the estimation of dose rates to biota (a set of reference organisms by default). The highest activity concentrations were found in sediment samples of Sidi Moussa Lagoon, possibly due to the anthropogenic activities, while the lowest levels were reported in Sebou estuary, attributed most probably to a flooding event that occurred in the same year of sampling. Also, 210Pb and 40K have the most significant concentrations, while 137Cs has the lowest concentrations with a great resemblance with similar works. The World Wide Average concentration of 226Ra was exceeded in the three lagoons and that of 40K only exceeded at Sidi Moussa Lagoon. The application of ERICA tool allowed the assessment of total dose rates that are mainly due to internal exposure with strong contribution of 226Ra mainly for phytoplankton in the case of marine ecosystems and insect larvae, mollusc-bivalve, mollusc-gastropod and zooplankton for estuary ecosystems. The total dose rates were far lesser than the admissible dose rate proposed by ERICA tool (10 μGy h-1) and, therefore, unlikely to cause harmful effects to organisms.