Laboratory of Marine Geosciences and Soil Sciences (URAC 45), Department of Geology, Faculty of Sciences, Chouaib Doukkali University, 24000 El Jadida, Morocco.
Casaccia Research Centre, Department for Sustainability, ENEA, 00123, Rome, Italy.
Environ Monit Assess. 2022 Apr 11;194(5):356. doi: 10.1007/s10661-022-10002-1.
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.
滨海泻湖是陆地和海洋之间的过渡地带，具有重要而敏感的环境意义。克尼菲斯泻湖是摩洛哥最重要的沙漠湿地，但关于其沉积物中的重金属地球化学和富集情况的数据却很少。因此，2016 年采集了 26 个表层沉积物（15 个潮间带和 11 个潮下带）和 2 个沉积物岩芯，用于分析选定的重金属。利用几种积累/富集指数和单一及多金属风险指数对数据进行处理，以评估污染程度和相应的潜在生态风险。根据地质年代分析，两个岩芯的底层数据代表了前工业化时代的当地地球化学背景。这些得出的数值总体上低于摩洛哥东北海岸其他地区的报告值。还应用了多元统计分析，以更好地理解变量（金属和其他地球化学参数）之间的关系，并揭示样本组之间的相似性。结果表明，尽管泻湖尚未受到明显的人为影响，但可以识别出小的富集，特别是 Ni 和 Cd。原因可能与靠近主要的国家高速公路、该地区盐场使用的车辆和机械以及主要用于渔业的小港口有关。此外，摩洛哥大西洋沿岸和邻近国家的工业排放也可归因于富集的额外贡献。在潜在生态风险方面，与所研究的其他金属相比，Cd 显示出最大的影响。
