Africa Water, Sanitation & Hygiene Africa Water & Sanitation & Hygiene May -June 2017 | Page 17

2017 • • • • • • • • space on the planet by volume Over three billion people depend on marine and coastal biodiversity for their livelihoods Globally, the market value of marine and coastal resources and industries is estimated at $3 trillion per year or about 5 per cent of global GDP Oceans contain nearly 200,000 identified species, but actual numbers may lie in the millions Oceans absorb about 30 per cent of carbon dioxide produced by humans, buffering the impacts of global warming Oceans serve as the world’s largest source of protein, with more than 3 billion people depending on the oceans as their primary source of protein Marine fisheries directly or indirectly employ over 200 million people Subsidies for fishing are contributing to the rapid depletion of many fish species and are preventing efforts to save and restore global fisheries and related jobs, causing ocean fisheries to generate US$ 50 billion less per year than they could As much as 40 per cent of the world oceans are heavily affected by human activities, including pollution, depleted fisheries, and loss of coastal habitats Scope of the Challenge Oceans sustain life on earth. They shape the climate, feed the world, and cleanse the air we breathe. They are also vital to our economic well-being, ferrying roughly 90 percent of global commerce, housing submarine cables, and providing roughly one-third of traditional hydrocarbon resources (as well as forms of energy such as wave, wind, and tidal power). But the oceans are increasingly threatened by a dizzying array of dangers, from the resource competition and overfishing to climate change and pollution. Threats to the world’s ocean are inherently transnational, touching the shores of every part of the world, and almost universally exacerbated by poorly regulated human activity. Nearly 30 percent of the world’s fish stocks are depleted due to overexploitation. Meanwhile, port-based megacities dump pollution into the oceans, exacerbating the degradation of the marine environment and the effects of climate change. In addition, the oceans have become the world’s garbage dump—at the heart of the Pacific Ocean, scientists have discovered the North Pacific Gyre, where particles of plastic outweigh plankton six to one. While the oceans have always been farmed for their immense resources, new technologies are making old practices unsustainable; when commercial trawlers scrape the sea floor, for instance, they bulldoze entire ecosystems. And while commercial ships remain on the surface, they produce carbon-based emissions that pollute the air. When carbon dioxide is released into the atmosphere, much of it is absorbed by the world’s oceans. The water, in response, warms and acidifies, destroying habitats like wetlands and coral reefs, and resulting in expansive dead-zones along many coastlines. And, glacial melting in the Polar Regions is raising global sea levels, which threaten not only marine ecosystems but also humans who live on or near coasts. Innovations like offshore drilling and deep seabed mining are helping humans extract resources from unprecedented depths, but with questionable environmenta l consequences. With the melting Arctic emerging as a promising frontier for entrepreneurial businesses and governments, access to the northernmost oceans portends Africa Water, Sanitation & Hygiene • May - June 2017 17