Eco-enhanced Seawalls Enrich Surrounding Marine Environment

30/11/2020

The Airport Authority Hong Kong (AAHK) is committed to environmental sustainability, including the conservation of the marine environment that surrounds Hong Kong International Airport (HKIA). In particular, the Marine Ecology and Fisheries Enhancement Strategy for the expansion of HKIA into a three-runway system (3RS) was set up to promote the enhancement of the marine environment. The strategy also supports measures that could contribute to the enrichment of marine ecology and fisheries resources in the vicinity of the project area.

As part of this effort, the artificial seawalls of the 3RS project have incorporated environmentally-friendly features with the addition of over 500 eco-enhanced concrete blocks. The first batch of these bespoke eco-blocks were installed on the eastern and northern vertical seawalls last year.

These eco-blocks incorporate a range of design features including small-scale pools, grooves and pits intended to promote colonisation of the physical seawall structure with a more diverse range of marine organisms, compared to normal artificial seawall blocks.

Scattered along the vertical seawalls are eco-enhanced concrete blocks that enrich marine biodiversity (top); and rock pools that provide shelter for organisms from currents and waves (bottom).
Scattered along the vertical seawalls are eco-enhanced concrete blocks that enrich marine biodiversity (top); and rock pools that provide shelter for organisms from currents and waves (bottom).

Some of the vertical seawall blocks also incorporate larger rock pools which provide more substantial shelter and protection for marine organisms. While the eco-enhanced blocks are specifically intended to add ecological value to our new seawalls, all of the designs have considered how to minimise bird attraction in these locations close to the airfield, in order to safeguard aircraft operational safety.

A one-year monitoring programme is helping to quantify the positive ecological impacts gained from these innovative features.

Marine fauna flourishing on the eco-enhanced concrete blocks.
Marine fauna flourishing on the eco-enhanced concrete blocks.

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