Initiatives before Yamashita Park

Last update date April 1, 2021

First of all,

This is the steel slag product used
Steel slag products used

In the waters of Yamashita　Koen-mae, the amount of oxygen (dissolved oxygen) in seawater decreases at places deeper than -3.0m in summer, and it is known that the biological habitat is harsh. Therefore, Yokohama City and JFE Steel Co., Ltd. have collaborated to create a shallow area with a depth of about -3.0m using recycled steel slag recycled materials, etc., and place a biological deposition base (such as living creatures, escape places, etc.) We verified the effect of improving the environment.

Survey site

The survey was conducted in the Yamashita　Koen-mae area.

Survey results

Changes in the sea

Changes in underwater conditions

Water purification by living organisms

Based on the results of a one-year survey in 2016, we estimated the amount of filter water by filtration edible organisms such as bivalves and squirts (creatures that feed as if they rubbed) was estimated to be about 11,000 kl per day (equivalent to 22 cups of 25m pool) It was estimated that seawater was filtered.

In the sea of Yamashita　Koen-mae after the shallow ground

Changes in living organisms in Test Area A

There was an increase in living organisms after installation. In summer, there is a decrease in the number of organisms estimated to be caused by poor oxygen, but the number of confirmed species has tended to recover thereafter. In addition, bivalves (mollular animal gates) and squirts (protozoic gates) of filter organisms that contribute to water purification have been identified.
A survey conducted in August R1 showed a wide range of hydrophilic leoplasms (system animal gate) in a wide area.

This is a graph of the number of confirmed types and degree of Yamashita　Koen-mae.
※The results of the calculation of the entire test area A, including natural stones, both the number of confirmed types and the degree of coverage are shown.

This is a graph of the number of confirmed types of target areas.

Survey reports, etc.

In order to open PDF files, you may need a separate PDF reader.
If you do not have it, you can download it free of charge from Adobe.
To download Adobe Acrobat Reader DC