Enhancing biodiversity on artificial coastlines with eco-engineered rock pools: Evidence from the Persian Gulf and Gulf of Oman

Coastal urbanization and climate change are driving the rapid expansion of artificial coastal structures worldwide, often at the cost of natural habitats and biodiversity. Eco-engineering approaches offer promising solutions to mitigate these negative impacts, yet remain largely unexplored in the Persian Gulf and Gulf of Oman — regions experiencing both extreme environmental conditions and intensive coastal development. In this study, we assessed the ecological effectiveness of water-retaining structures (rock pools) incorporated into artificial infrastructures at three locations across the Strait of Hormuz and Gulf of Oman. Monthly monitoring of 41 water-retaining structures over a year resulted in the identification of 25 taxa, including gastropods, polychaetes, barnacles, and other intertidal species. Rock pools significantly enhanced species richness and abundance compared to emergent surfaces, with local environmental conditions influencing abundance patterns. Repeated measures ANOVA confirmed significant temporal variation, and PERMANOVA analyses revealed clear differences in community structure among locations. Notably, native species dominated the assemblages, suggesting that eco-engineered structures can promote native biodiversity even under highly stressful conditions. Our findings show that integrating rock pools into coastal infrastructure offers essential microhabitats that buffer environmental stressors, increase species diversity, and contribute to ecosystem resilience. This study represents one of the first empirical applications of marine eco-engineering in the Persian Gulf and the Gulf of Oman, providing important lessons for strategies aimed at more biodiversity-friendly coastal development in arid and tropical environments.