Rhodoliths (nodular calcareous red algae) are considered one of the most important bioengineers in the Mediterranean Sea, making rhodolith beds ecologically relevant ecosystems. On the insular shelf surrounding the western Pontine Archipelago (depth from 43 to 112 m), rhodolith beds were identified through the analysis of an extensive dataset of grab samples and videos to ground-truth the backscatter acoustic facies. Six acoustic facies (low backscatter, dishomogeneous low-backscatter, dishomogeneous high-backscatter, high-backscatter, rocks and high backscatter, and rocks and medium backscatter) were recognized. We studied how rhodoliths characteristics (density, morphotype, size and structure) differently influence the backscatter signature. At the western Pontine Archipelago, rhodolith beds are mainly represented by facies dishomogeneous high backscatter, high backscatter, high backscatter with rocks, and medium backscatter with rocks. The obtained results increase both the knowledge on the heterogeneous structure of such ecologically relevant benthic habitat and highlight the use of distinctive acoustic facies for their identification. Finally, the used approach could be considered a useful method for indirect detection and mapping of rhodolith beds.

Rhodoliths（结节状钙质红藻）被认为是地中海最重要的生物工程师之一，使Rhodolith床成为生态相关的生态系统。在西部庞廷群岛周围的岛架上（深度从43到112 m），通过对大量抓取样本和视频数据进行分析，找出了真石背层，以确认真石背散射声相。识别出六个声相（低反向散射，同质低反向散射，同质高反向散射，高反向散射，岩石和高反向散射以及岩石和中等反向散射）。我们研究了菱纹石的特征（密度，形态，大小和结构）如何不同地影响后向散射特征。在西部的邦丁群岛，斜纹岩床主要表现为同相的高后向散射，高后向散射，岩石高向后散射和岩石中向后向散射。所获得的结果增加了对这种生态相关底栖生境的异质结构的认识，并突出了利用独特的声相进行识别。最后，所使用的方法可以被认为是用于间接检测和绘制菱锰矿床的有用方法。