When we see factories near the seashore releasing the high temperature wastewater, coral reef and fish living around the environment are facing life-threatening problem. In this case, the death of coral reef and the migration of fish will happen. Therefore, we aim to design an industrial product combined with science and chemistry to help lower the temperature and bring coral reef ecosystem back to life. ALGA KAISOU is made of two parts. One is the body structure, using the biodegradable material, PLM, could be decomposed by microorganism with time passing by. Another part is the coating, Spinel-type transition metal oxide. The state of coating is unstable because of having energy level. By absorbing the heat from water, the state of coating becomes stable. In the process of decreasing the temperature of sea water, a part of energy can be transferred into working on decomposing PLM. In the ideal condition, the coating will not reach the stable state until the PLM is decomposed.