Seaweed Bed Formation and Possibility of Control of Seawater Quality by Using Water-soluble Glass

Abstract

To promote seaweed and phytoplankton propagation, a new glass material named Ionculture was developed. Ionculture supplies minerals such as phosphorus, silicon, iron, and other trace elements into the sea slowly.

As a substrata for seaweed, mortar plates with exposed glass granules, "Ionculture plates", were experimentally used. The iron (Fe²⁺) dissolved out of the glass materials on the plates and helped seaweed to grow. The individual number and standing crops of seaweed on these plates were I to 2 times higher than with the blank plates. In particular, in the early stage of growing seaweed, it was obvious that the glass had a beneficial effect on growth.

Another application of the glass materials is the potential as a seawater quality controller. The death of oysters and pearl oysters occur every summer to autumn due to red tide; Hetrocapsa sp., and infection. During this season, there is a scarcity of phytoplankton.such as diatoms, the essential food for bivalves. Due to the lack of silicon in the seawater, red tide plankton such as Dinophyceae appear in abundance instead of the diatoms. The possibility of using Ionculture as a silicon supplier is discussed herein.