Oceans, which gave rise to all life on our planet, play a vital role in sustaining all life forms, not least humankind. The ability of oceans to continue to do so is now under grave threat from human impacts.
According to the Food and Agriculture Organization of the United Nations (FAO), in 2012 the oceans provided more than 200 million direct employment opportunities along the food value chain, of which 58 million were in fisheries or aquaculture. They also estimated that the livelihood of roughly 12% of the global population (880 million people) was assured by the latter industries, for the same year.
The productivity of the ocean ecosystems is, however, threatened by a number of factors, including overfishing, pollution, and acidification. This is evidenced, for instance, by the WWF Living Planet Index (LPI) for marine populations, which is based on trends among 1,234 marine species, and shows a decline of 49% between 1970 and 2012. In addition, the Intergovernmental Panel on Climate Change (IPCC) asserts that the three principal impacts of climate change on the world’s oceans – warming, oxygen depletion, and acidification – will substantially alter ocean ecosystems.