Administrative districts of Japan’s coastal regions are complicated and interwoven. Many coastal organisms traverse these administrative districts through their life histories. While the Great East Japan Earthquake greatly impacted human society, nature in coastal areas has steadily recovered. Disaster-resilient infrastructure including against storm surges and tsunamis could present a possible win-win relationship with the conservation of ecosystems. However, in order to realize this, it is necessary to look again at coastal preservation areas designated by the Coast Act and other laws from an ecosystem perspective.