Algal diversity in aquatic environments can help assess the health status of ecosystems, provide information about invasions of new species and inform species diversity changes according to environmental conditions. An algal diversity survey (2016–19) of Nador Lagoon (northern Morocco) revealed the presence for the first time of the brown alga Cystoseira aurantia . Since 2015 this alga has been found in high abundance in the northwestern part of the lagoon, mainly around Attalayoun and Nador City. The thalli of larger specimens reached 60 cm in length, and all plants present were free-floating. The species was collected from the water surface to depths not exceeding 2 cm. Floating patches were usually found suspended above sandy and muddy substrates. Increased abundance of this species in the lagoon corresponds with new physico-chemical conditions and ecological parameters, principally resulting from increased water ventilation and improved water quality since 2012. The new communities of C. aurantia may offer a novel resource for the lagoon but high abundance could pose future threats to attached vegetation such as seagrasses and benthic algae by shading and the accumulation of organic detritus. Attention is drawn to taxonomic issues involving C. aurantia .

中文翻译：

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摩洛哥地中海沿岸的Cystoseira aurantiaKützing的首次报告

水生环境中的藻类多样性可以帮助评估生态系统的健康状况，提供有关新物种入侵的信息，并根据环境条件告知物种多样性变化。Nador Lagoon（摩洛哥北部）的一项藻类多样性调查（2016-19年）显示，首次存在褐藻Cystoseira aurantia。自2015年以来，在泻湖的西北部（主要在阿塔拉扬和纳多尔市附近）发现了大量藻类。较大标本的塔利达到60厘米长，所有存在的植物都自由漂浮。该物种从水面收集到不超过2厘米的深度。通常发现漂浮的小块悬浮在沙质和泥泞的基质之上。自2012年以来，泻湖中该物种的丰度增加与新的理化条件和生态参数相对应，这主要是由于自2012年以来水流通量增加和水质改善所致。C. aurantia的新群落可能为泻湖提供了一种新颖的资源，但丰度很高可能通过遮蔽和有机碎屑的积累对诸如海草和底栖藻类等附着的植被构成未来的威胁。请注意涉及C. aurantia的分类学问题。aurantia可能为泻湖提供了一种新颖的资源，但高的丰度可能会通过遮蔽和有机碎屑的积累对附着的植被（例如海草和底栖藻类）构成未来的威胁。请注意涉及C. aurantia的生物分类问题。aurantia可能为泻湖提供了一种新颖的资源，但高的丰度可能会通过遮蔽和有机碎屑的积累对附着的植被（例如海草和底栖藻类）构成未来的威胁。请注意涉及C. aurantia的分类学问题。