Gas hydrate could be the most important future energy source. The total known carbon reserves in the form of gas hydrate are more than those in existing oil reservoirs. Sudden release of gas hydrate could be a major factor for the cause of tsunami. In addition, large climatic changes of the earth history could relate to the release of gas hydrate in marine environments. Synbionts communities observed in the deep marine cold seep venting environment are another primary production with energy from chemosynthesis. The seminar will require participants to conduct literature searches of the current developments in gas hydrate research and present their search results orally in class.