Abstract
Abstract
Coastal seascapes are increasingly dominated by artificial structures of limited ecological value. This study tested whether 3D-printed eco-engineered wraps, designed to recreate natural intertidal rock-pool habitat, can enhance biodiversity and buffer thermal extremes when retrofitted to marine piles in a tropical urban estuary (Townsville, Australia). Epibenthic assemblages on eco-engineered and control piles were surveyed at 2, 4, 7, 9 and 12 months after deployment, across shaded and sun-exposed orientations and three tidal heights, while temperature was logged hourly inside and outside the rock pools and on control piles. The rock pools were consistently cooler than control surfaces, by approximately 0.8°C on average and up to 1°C on shaded aspects, and buffered extremes far more strongly, reducing the highest recorded temperature by up to 6.5°C. Eco-engineered piles supported a distinct and more diverse assemblage than control piles (functional-group richness 2.8 versus 1.6; Shannon diversity 0.71 versus 0.26), and this difference widened as colonisation proceeded. Control piles converged on a barnacle-dominated monoculture and lost cover late in the study, whereas eco-engineered piles maintained high cover and little bare space (88% versus 60% cover at twelve months). Tube worms were largely restricted to eco-engineered piles, and crabs were frequently observed sheltering within the wraps, although neither was quantified by the survey method. This spatial concordance between thermal buffering and biodiversity indicates microhabitat-scale thermal refuge as a plausible mechanism. Retrofitting piles with eco-engineered wraps can therefore enhance biodiversity and moderate thermal extremes, supporting eco-engineering for ecological enhancement of urban seascapes.