[Summarizing an article in English] Conserved sea around the Kansai International Airport
https://www3.nhk.or.jp/news/html/20230331/k10014023981000.html
At sea around the Kansai International Airport, Osaka City in Osaka Prefecture, the fishery is prohibited due not to disturb airplanes operations. Moreover, the area is heavily guarded for security reasons. These led to a rich ecosystem in this area.
The airport was constructed in 1970's, when Japan was at its high growth of economy. There were many projects of industry development and land forming. These development destructed habitats of various living things eventually. In reflection of this situation, the government aimed to construct a nature-friendly airport.
It has bank protection of 24km around the reclaimed land, and 80-90% of it is inclined. It can get more sunshine compared to a vertical bank to allow seaweeds to grow well. After 30 years, there is a marine forest with more than 100 species of seaweeds, which is called "a cradle of lives" providing spawning ground and hideout to fishes. There are small fishes and crams that eat seaweeds. These livings attract bigger ones, the predators, such as stingrays. They have been observed since ten years ago in the area. Researchers guess that they settled due to enough food.
One of the habitants that most symbolize how rich the are is is an Asian sheepshead wrasse. It has a swelled out forehead and jaw and can grow up to 1m body length. The reporter observed more than ten of them during its field research. A researcher of this species said the large marine forest provides plenty of food so that they don't need to fight over the territory with each other. There are no other areas that have a population that much in Japan, he also mentioned.
Osaka prefecture will hold an international exposition in two years. Expecting it, the operating company of the airport has started a project to expand a marine forest in Osaka bay. It aims to make the whole bay more biodiverse and show worldwide its effort to coexist with nature in the city area.