Manila, Philippines — While the health of the oceans is vital to all of humanity, it is the world's poorest people, the majority of the world's coastal inhabitants, who are most vulnerable to ocean degradation. Oceans are their primary source of food, crucial to their livelihoods, and a major force in shaping their cultures. Oceans are their life. Yet, as described by Andrew Hudson, head of UNDP's International Waters program, oceans are under assault. Pollution, overfishing, acidification, warming, and the introduction of non-native species are causing ecological damage, habitat loss and species extinction and throwing new obstacles across the path out of poverty for millions of people throughout the developing world.Oceans cover three-fourths of the earth's surface. They contain 97% of the earth's water, and represent 99% of the living space on the planet by volume. They are home to nearly 200,000 identified species, though actual numbers may lie in the millions.Oceans are the world's largest source of protein and the primary source of protein for over 2.6 billion people. In some parts of the world, such as West Africa, fisheries represent thirty percent or more of export earnings and provide local livelihoods for hundreds of thousands of coastal fishermen. Worldwide, marine fisheries employ over 200 million people, directly and indirectly. Oceans directly provide over $500 billion in annual economic goods and services plus an estimated $20.9 trillion per year in non-market ecosystem services, about 63 percent of the value of all such services. Ninety percent of all internationally traded goods are transported on the oceans.Unfortunately, our oceans remain under assault from a variety of pressures, including pollution (mostly land-based), overfishing, introduced species, habitat loss and species extinction, and poorly planned and managed coastal development. Around half of global fish stocks are fully exploited, and a quarter are depleted, over-exploited or recovering from depletion. Less than 0.5 percent of marine habitats are protected, compared with 11.5 per cent of global land area. The number of dead zones, caused by excess nutrient pollution to coastal zones, has been expanding at a geometric pace in recent years, with associated losses to ecosystems and the livelihoods that depend upon them. Invasive marine species, especially those carried in ship ballast water, cause an estimated $100 billion each year in economic damage to infrastructure, ecosystems and livelihoods.Anthropogenic climate change from greenhouse gas emissions only complicates an already challenging ocean management situation. Climate change is already affecting ocean temperatures and both horizontal and vertical ocean circulation, driving fish stocks to migrate to more favorable waters. The oceans are estimated to have absorbed about 25 percent of anthropogenic carbon dioxide emissions. While this has served to mitigate atmospheric warming to some extent, it has had the negative effect of increasing the acidity of the oceans by 30 percent, with significant threats to calcium carbonate fixing organisms that serve as the foundation for many ocean food chains upon which hundreds of millions depend upon for protein and livelihoods. Sea level rise, due to both the thermal expansion of seawater and glacial melt, threaten millions living in the coastal zone and island states, mostly in the world's least developed countries.Protecting and restoring our precious oceans requires a range of strategies including ecosystem-based approaches, integrated coastal zone management and expanding protected areas to include high seas areas. A range of effective tools have been piloted and are ready for up-scaling, such as tradable fisheries quotas, new ballast water management and treatment technologies, and improved nutrient management in river basins feeding coastal zones. Given the significant impacts, both present and future, of climate change on the ocean resources upon which most of humanity depend, rapid progress on a strategic approach to mitigate greenhouse gas emissions represents a critical commitment if we are to meet the ocean challenge.UNDP is working in cooperation with many other UN agencies, the Global Environment Facility, international financial institutions, and others to improve oceans management and sustain livelihoods at the local, national, regional and global scales. UNDP is supporting ecosystem-based approaches to fisheries management in over ten of the world's 'Large Marine Ecosystems', where 85 percent of the world's fish catch derives. UNDP, through its PEMSEA programme, has pioneered best practices in integrated coastal management and is supporting 12 East Asian countries in the rapid up-scaling of these efforts. UNDP is partnering with the International Maritime Organization in a long-term effort to reduce dramatically the risk of transfer of invasive species through ship ballast water through governance reform and technology development and transfer.World Oceans Day provides the opportunity for each of us to reflect on what the oceans mean to us, and what we need to do to help protect and sustain our vital oceans resources for future generations.