Development of environment-oriented base materials for seaweed beds by recycled materials

The area of seaweed beds along Japanese coasts has decreased by approximately 40% in the last 40 years due to climate change and human activity. In addition, there are similar concerns regarding coastlines worldwide. Thus, it is critical to recover seaweed communities quickly to maintain marine plants and environments. The frequency of eruptions at Mt. Sakurajima in the Kagoshima Prefecture of the Kyushu region peaked in 2011 and was the highest since observations began in 1955. Additionally, large amounts of waste material, such as scrap ceramics and gypsum, are discharged from the ceramics industry in the Saga and Nagasaki Prefectures of Kyushu, Japan. The effective use of volcanic ash and industrial wastes (scrap ceramics and gypsum) represents an important problem that must be solved in the Kyushu region of Japan. The objective of this study is to develop environmentally oriented base materials for seaweed beds with a low environmental load using volcanic ash and several recycled materials from industrial waste. The developed base materials were placed into Kagoshima Bay in May 2013, and monitoring began. A discussion of the results of long-term monitoring over 4 years and 2 months is presented.