Goal 14: Conserve and sustainably use the oceans, seas and marine resources for sustainable development

Fisheries contribute significantly to global food security, livelihoods and the economy. However, if not sustainably managed, fishing can damage fish habitats, reduce biodiversity and impair the functioning of ecosystems with negative repercussions for sustainable social and economic development. To achieve a healthy balance, fish stocks must be maintained within biologically sustainable limits—at or above the abundance level that can produce the maximum sustainable yield. Based on an analysis of assessed stocks, the proportion of world marine fish stocks within biologically sustainable levels declined from 90 per cent in 1974 to 69 per cent in 2013 and appears to have stabilized over the last few years.

Protecting biodiverse marine sites is vital for ensuring the sustainability of marine biodiversity and ecosystem services. In 2014, 8.4 per cent of the marine environment under national jurisdiction (up to 200 nautical miles from shore) and 0.25 per cent of the marine environment beyond national jurisdiction were under protection. Both developed and developing regions increased their protection of marine areas from 2000 to 2014. However, much of the increase was due to the establishment of large protected areas around a few countries and in sites not necessarily targeted for biodiversity. Consequently, marine protected areas are not evenly distributed, and the differences across regions are significant. In Oceania, the share of protected marine and coastal areas grew from 0.1 per cent in 2000 to 7.4 per cent in 2014—the largest percentage among developing regions. To ensure that marine habitats and species are not lost, these protected areas need to be effectively managed and cover key biodiversity areas, which are sites significant for the global persistence of biodiversity. From 2000 to 2016, the share of marine key biodiversity areas that were completely covered by protected areas increased from 15 per cent to 19 per cent.

Coastal regions are particularly vulnerable to pollution. Since river basins, marine ecosystems and the atmosphere are all part of hydrological systems, the effects of pollution are often felt far from their source. In many coastal communities, pollution and eutrophication—excessive nutrients in water, frequently due to runoff from land, causing dense plant and algal growth and the death of animal life from lack of oxygen—have been key factors driving detrimental changes. According to the Transboundary Waters Assessment Programme global comparative assessment in 2016, the five large marine ecosystems most at risk from coastal eutrophication are the Bay of Bengal, East China Sea, Gulf of Mexico, North Brazil Shelf and South China Sea, areas which provided ecosystem services for coastal populations of 781 million in 2010.