Restoring wetlands outside of the seawalls and to provide clean water habitat.

In this study, we reported a practice at northern Hangzhou Bay, southeast China aimed at restoring coastal wetlands within the intertidal zone outside of the seawalls. The principle idea is protecting the site and helping the marsh establishment by engineering measures, and thereafter, relieving the protections to encourage the self-organization of the restored ecosystem. The results of this implementation showed the marsh reached an average vegetation cover of 70% in the first year. The excess nitrogen was removed by an ecological recirculating treatment system, which was coupled in the wetland. The long-term performance of the wetland suggested that it could resist disturbances such as hurricanes and algal blooms, and provided clean water habitat for aquatic fauna. By presenting the case of Hangzhou Bay, we call for more novel coastal restoration implementations that aim to create new boundaries with engineering features and self-organization, which benefit both human and nature.