Eco-shoreline designs for sustainable coastal development

Abstract

Conventionally, reclamation and marine infrastructure projects often adopted simple artificial vertical or slope seawalls as coastal defenses against wave action, flooding and land erosion. But, these structures do not possess any microhabitats that can be readily occupied and used by marine organisms as refuges and feeding grounds. Through incorporating the knowledge of marine ecology and collaboration with ecologists, engineers now are able to design eco-friendly artificial structures (e.g. eco-concretes, bio-blocks, reef balls) to serve dual roles as coastal defenses and functional ecosystems for enhancing marine biodiversity and ecosystem service. For instance, filter feeders like mussels and oysters which grow on these eco-friendly structures will be able to filter and clean up the coastal seawater, while serving as food sources for other marine predators (e.g. crabs, fishes and humans) and as habitats for other organisms to reside. Apart from having engineered structures made of artificial substrates, it is also possible to create living eco-shorelines using natural materials; typical examples include artificial wetlands and intertidal rock pools. Such imitated natural habitats can accommodate many different living organisms and hence augment biodiversity and ecosystem functions, while providing natural landscape for people to enjoy. In this talk, I will introduce the basic ecological principles for eco-shoreline designs and draw examples from different parts of the world. I will particularly highlight the World Harbour Project (www.worldharbourproject.org) and ongoing trials of eco-shoreline designs carried out in Hong Kong and China. Opportunities and obstacles of the development of eco-shorelines will be discussed.