An algal bloom is a phenomenon in which planktonic algae (phytoplankton) are mass propagated in eutrophicated lakes or rivers with slow velocity of flow and accumulated on surface, thereby drastically changing water color into green. The algal bloom is one kind of hydration and only indicates the phenomenon that the water color is changed into green by mass propagation of cyanobacteria. The algal bloom is named through newspapers or broadcasts by the fact that water color is changed into green compared to red tide. Such algal bloom has bad influences on freshwater and causes serious problems including visual influences, influences of toxicity on human body and domestic animals, ecological problems due to ecocide, death of fishes and various underwater creatures due to oxygen deficiency, and the like. The present invention relates to an extermination substance against algae blooms for effectively exterminating causal organisms of algae blooms which bring great damages to freshwater. The present invention manufactures an environment-friendly mixture and applies the same to algae blooms to exterminate the algae blooms. In order to fundamentally solve the algae bloom problems, the present invention manufactures the extermination agent against algae blooms using cobbles, barley stones, and charcoal powder as main ingredients and adding additives. The extermination substance against algae blooms according to the present invention has higher algae bloom rescue efficiency than that of conventional extermination agent against algae blooms does not cause secondary environmental pollution and can be mass produced at low cost.COPYRIGHT KIPO 2015녹조현상이란 부영양화된 호수나 유속이 느린 하천에서 부유성의 조류(식물프랑크톤)가 대량 증식하여 수면에 집적하여 물색을 현저하게 녹색으로 변화시키는 현상"을 말한다.녹조현상은 수화현상의 한 종류로 남조류의 대량 증식으로 인해 물색이 녹색으로 변하는 현상만을 의미한다. 실제 녹조(錄潮)현상 이라는 말은 적조현상과 비교하여 물색이 녹색으로 변한다고 하여 신문이나 방송을 통해 붙여진 이름이다.이러한 녹조현상은 담수에 심각한 악영향을 미치고 있다. 시각적인 악영향은 물론이고, 독소에 의한 인체 및 가축에의 영향, 생태계 파괴로 인한 생태학적인 문제, 산소결핍으로 인한 물고기 및 각종 수중생물 폐사 등등의 심
