Advancing coral reef ecological engineering for large‐scale seascaping on soft seabeds: a comparison of tiered and biomimetic artificial reef designs

In a context where entire marine regions are in decline and many coral reef systems have collapsed, creating novel coral reef ecosystems on soft‐bottom seascapes can serve as ecological restoration at a regional scale. However, seascaping reef infrastructure in sandy environments presents unique engineering challenges distinct from traditional reef restoration. This study evaluates two artificial reef designs for coral farming: the tiered Marjan Reef and the biomimetic Mushroom Forest Reef (MFR). Both were deployed offshore in Qatar as part of an environmental compensation program involving the transplantation of 4310 coral colonies (10 species) from oil and gas pipeline corridors—843 onto 21 MFR units and 3467 onto 63 Marjan units. Under thermal stress (seawater temperatures reaching 36°C), MFR significantly outperformed the Marjan Reef, with 90% of colonies Healthy, 9.9% Partially‐Dead, and 0.49% Dead. In contrast, the Marjan Reef showed 73% Healthy, 25% Partially‐Dead, and 4% Dead colonies, likely due to shading, sediment accumulation, and boring sponge colonization on its lower tiers. MFR minimized these stressors, enhancing coral survival and cost‐efficiency. For instance, installing 1 ha of coral farming infrastructure would require 51 MFR units, five deployment days, and provide approximately 300 m 2 of farming surface. These results support the concept of utilizing the creations of “coral oasis reservoirs” in regional resource management—engineered reef units that function as biodiversity hotspots in soft‐bottom marine deserts. These oases offer a scalable solution for coral propagation in novel environments, advancing broader ecological restoration and “Assisted Marine Rewilding” in the Anthropocene.