The IOC aids and advises policy makers and managers in the reduction of risks from tsunamis, storm surges, Harmful Algal Blooms (HABs) and other coastal hazards. After close to fifty years of experience coordinating the Pacific Tsunami Warning System (PTWS), IOC-UNESCO is leading a global effort to establish ocean-based tsunami warning systems as part of an overall multi-hazard disaster reduction strategy. The IOC Tsunami Unit works with Member States, together with other UN agencies and NGOs, to build sustainable tsunami early warning systems. In this context, the IOC coordinates and fosters the establishment of regional intergovernmental tsunami warning and mitigation systems in the Pacific Ocean and Indian Ocean, in the Caribbean, and in the North East Atlantic, the Mediterranean and connected seas. Through its Intergovernmental Panel on Harmful Algae (IPHAB), the IOC also works to establish systems that can predict the occurrences and mitigate the effects of HAB events.