Environmental science is one of the strategic research areas of Hong Kong Metropolitan University (HKMU). Dr Juan Carlos Astudillo Placencia, Assistant Professor in the School of Science and Technology, will start to work on a research project which involves exploring eco-engineering works at the rip rap seawall in south Hong Kong through the use of innovative eco-concrete features to augment habitat complexity. Through this project and his other innovative research, he hopes to demonstrate the benefits of eco-engineering of seawalls to the general public.

Dr Astudillo is a marine ecologist with strong interest and experience in marine biodiversity assessment, invasive biology and ecological engineering for habitat rehabilitation. With his deep concern for Hong Kong's marine health, he has been actively involved in a number of ecological engineering and environmental restoration projects that provide solutions for enhancing the city's marine biodiversity, focusing on the development of innovative eco-friendly building materials, such as eco-tile.

As a result of urban development and large-scale land reclamation, Hong Kong's natural coastline has been increasingly replaced by artificial seawalls, mostly with plain concrete structures that cause habitat loss and a decrease in marine life, affecting the health of the environment and water quality. Dr Astudillo, in collaboration with academics from the State Key Laboratory of Marine Pollution of the City University of Hong Kong and The Hong Kong Polytechnic University, developed the eco-tile by upcycling ashes from the Tuen Mun T-Park incinerator and marine sediment from dredging of Hong Kong harbour or navigation channel to create a mimetic of a natural habitat for the “concrete seawall” resulting from land reclamation, thereby promoting biodiversity and easing the problem of municipal solid waste at the same time.

The eco-tile encourages the growth of marine life and contributes to a healthy ecosystem. The crevices and holes in the eco-tile harbour twice as many marine species, from oysters to fish, as traditional seawalls commonly used around the world. These species can promote seawater filtration and sustainable fisheries. Made from recycled materials, the eco-tile effectively reduces the carbon footprint by 20-40% compared to traditional concrete. In addition, it is applicable to various types of seawalls and environments globally. With future large-scale deployments, the barren seawalls around the world can be transformed into thriving, biodiverse ecosystems.

The project won a Gold Medal with Congratulations of the Jury and a Special Prize earlier at the 48th International Exhibition of Inventions Geneva, and also a Gold Medal in Asia International Innovation Invention Exhibition 2023. The honours are significant recognition of Dr Astudillo's efforts in fostering ocean health and healing the marine ecosystem, and also give a strong boost to HKMU's commitment to having a positive impact on the environment through innovative research.