An experiment to encourage biodiversity by creating an organic coastline has initially proven successful with the finding of 11 kinds of marine life, according to Secretary for Development Michael Wong Wai-lun.
In the secretary's blog yesterday, Wong said the Civil Engineering and Development Department is cooperating with the University of Hong Kong to run a feasibility study on increasing biodiversity on seashores.
Initial results at an experiment site in Ma Liu Shui saw 11 types of creatures settling on the seawalls, despite artificial shoreline not usually favoring organism growth, he explained.
The vertical seawalls consist of stacked concrete blocks with slippery surfaces. The lack of ponds and cracks can lead to organisms dehydrating and dying under the heat, leading to limited biodiversity.
"What we meant by creating an organic coastline is to make seawall design that simulates natural tides, which allows pooling of water and shades - an environment suitable for marine creatures to reside and grow, thus increasing biodiversity and bringing life to the seawalls," Wong said, quoting senior engineer Clive Lee Chi-kin.
The department and a HKU team set up monitoring equipment at sites in Sai Kung, Lung Kwu Tan in Tuen Mun and Ma Liu Shui in Ma On Shan.
The three sites have different natures: Sai Kung is oceanic, Ma Liu Shui is a semi-open water body, and Tuen Mun is a river environment. Once the experiment is finished, researchers hope to understand whether the add-ons are effective in encouraging marine life growth in different environments.
Beginning in January 2018, the research is expected to conclude in 2021 after two years of on-site experiments, which started last March.
The team introduced add-ons such as cubes that come with holes, cracks and rough surfaces. There are also baskets for oysters and mussels, and tidal pools which can store water when the tide is low.
Kenneth Leung Mei-yee, professor of HKU's school of biological sciences, said the first six months of monitoring proved encouraging.
"On some of the environmental friendly seawalls, 11 kinds of organisms which cannot be found on traditional seawalls were found, such as seaweed, coralline algae, crabs and snails," he stated.
Wong said while such enhanced seawalls are new to Hong Kong, there have been successful applications overseas, such as Barangaroo in Sydney and Haifa Bay in Israel.
"I hope in the near future, the environmental friendly seawalls can preserve marine diversity as well as encourage water-friendly culture among citizens," he said.