Abstract
In Inner bays used as aquaculture grounds water quality is continuously deteriorating. As a remedial measure, a technique has been proposed and examined to cake dredged bottom mud by mixing with caking agents and further utilize some of the caked bodies by placing them in or near the dredged sea region for eelgrass bed formation, which can be expected to improve water quality in the dredged inner bays. A verification test on the technique to reutilize bottom mud as an eelgrass settlement substrate was carried out in an oceanic water region. Bottom mud with a water content of 50% or higher was mixed with a caking agent at 2-5% in wet weight. The caked bodies did not result in re-suspension. Imbedded seeds were observed to germinate out of the caked bodies for settlement and growth on the caked bodies. An observation revealed that the cement caking agent was good for the germination and initial growth and the magnesium caking agent was relatively good at the declining phase.
