Assessing the Suitability of an Artificial Basaltic Substrate for the Rock-Boring Urchin Echinometra lucunter

Anthropogenic activities have created new marine habitats through artificial basaltic barriers intended to prevent coastal erosion. These barriers support a diverse range of species, including the rock-boring sea urchin Echinometra lucunter, important for controlling algae and providing habitat in tropical limestone areas. This study assessed the suitability of artificial basaltic substrates for E. lucunter by comparing two sites: basaltic vs limestone substrates. Two sites with different types of substrates were selected, abiotic, sea urchin abundance, aggregation, stress levels, and four morphometric measurements. Results showed that E. lucunter populations were more abundant, but also more stressed in the limestone substrate. Sea urchins found on basaltic barriers exhibited larger body sizes but had shorter spines, likely as an adaptation to the hardness of the substrate. They also clustered more in basaltic areas, possibly due to the rock's structure. Overall, basaltic substrates appear less suitable for E. lucunter compared to natural limestone substrate. Our findings raise important concerns about the suitability of such substrates for coastal marine life. This emphasizes the need for more research to understand their long-term effects, highlighting the need for further research on the long-term effects of artificial habitats on coastal species.