Protecting the oceans is crucial to societies’ survival because, as the United Nations has recognized, they “drive the global systems that make the Earth a habitable place for humans.” The world’s oceans regulate the climate, provide rainfall, produce oxygen, and are the main source of protein for more than a third of the global population: more than 3 billion people around the globe depend on marine and coastal biodiversity for their livelihoods. Oceans also absorb more than 90% of the excess heat due to climate change, and a quarter of human carbon dioxide emissions, so they are also essential to stabilizing the planet’s climate.
So far, though, humanity’s increasing carbon dioxide emissions have affected the health of the oceans by warming and acidifying seawater. The U.N. says this has not only “led to dire changes for life underwater and on land,” but also “reduced the ocean’s ability to absorb carbon dioxide and protect life on the planet.”
In this scenario, coastal waters are the hardest hit, since nearshore pollution compounds climate change stressors. Small-scale fisheries are located closer to the coast and are therefore the most affected. According to the U.N., “Without concerted efforts, coastal eutrophication” — the increase in inorganic nutrients from human activities, which causes accelerated algal growth, among other things — “is expected to increase in 20 percent of large marine ecosystems by 2050.”
To address the problem, the U.N.’s Sustainable Development Goals include creating effectively managed marine protected areas. In Chile, artisanal fishers from five communities have decided to help this global effort by protecting areas of the sea where they have historically fished and harvested shellfish.