8 June is World Oceans Day offering us all an opportunity to reflect on the importance of our oceans for our own health and well-being. If you really start to think about it though, and consider how critical oceans are, you will quickly realise that one day of appreciation a year seems very inadequate; especially when 40 percent of our global oceans are ‘heavily affected’ by human activities .
In the first place, our seas are critical to our livelihoods. They are particularly crucial for people living in coastal communities, who represented 37 percent of the global population in 2010. Oceans provide jobs in areas of the economy such as fishing or tourism and research, as well as subsistence and income [1,2].
Even if you never have a chance to see or touch the ocean, the ocean touches you with every breath you take, every drop you drink, every bite you consume. Everyone, everywhere is inextricably connected to and utterly dependent upon the existence of the sea.— Sylvia Earle – National Geographic’s veteran marine biologist
Healthy oceans equal healthy fish for the world’s poorest
Our oceans also contribute to food security. Fish, shellfish and seafood are key food categories for big parts of the population. However, if not sustainably managed, fishing can damage fish habitats.
Ultimately, overfishing impairs the functioning of ecosystems and reduces biodiversity, with negative repercussions for sustainable social and economic development. Based on an analysis of fishing stocks, world marine fish stocks operating within biologically sustainable levels declined from 90 percent in the mid-1970s to 69 percent in 2013 .
What is particularly significant is that a decline in fish populations poses greater risks for poor people in developing countries. According to the United Nations, 795 million people do not have enough to eat. 460 million of these people live in major fish-dependent nations, countries like the Philippines, Indonesia, and Mozambique. Seafood is a crucial source of healthy protein and important micronutrients like iron, omega-3 fatty acids, zinc and vitamins A and B12.
Lack of access to these nutrients risks creating dire health consequences for fish-dependent populations. A study found that as much as 10 percent of the world population, especially concentrated in equatorial developing nations, could face micronutrient and fatty-acid deficiencies due to declines in the availability of fish. From this point of view, saving the oceans is no longer a conservation goal only; it’s critical to ensuring global food security .
Healthy oceans equal healthy terrestrial ecosystems
Our seas and oceans have provided us with all these benefits while at the same time absorbing large chunks of the environmental implications our polluting activities have created. Since the beginning of the industrial revolution, the ocean has absorbed about one third of the carbon dioxide released by human activities, thereby mitigating the full impact of climate change.
However, this comes at a steep ecological price. Greenhouse gas emissions are increasing the acidity of the ocean and if we continue business as usual, the ocean could become 150 percent more acidic by 2100 . This would be catastrophic for all ocean life as it would lead to a reduction of plankton, threatening the survival of these organisms and unique ecosystems.
Beyond climate change, our oceans protect coastal areas from flooding and erosion. In fact, coastal and marine resources contribute an estimated $28 trillion to the global economy each year through ecosystem services. But there again, pollution of both land and seas is a threat in many coastal regions.
What is more, since river basins, marine ecosystems and the atmosphere are all part of hydrological systems, the effects of such pollution are often felt far from their source. In many coastal communities, pollution and eutrophication, which is the consequence of excessive nutrients in water, frequently owing to runoff from the land, causing dense plant growth and the death of animal life.
The five large marine ecosystems most at risk from coastal eutrophication, according to a global comparative assessment undertaken in 2016 as part of the Transboundary Water Assessment Programme, are the Bay of Bengal, the East China Sea, the Gulf of Mexico, the North Brazil Shelf and the South China Sea [1,2].
The ocean provides benefits to economic sectors such as fisheries, energy, tourism, and transport and shipping, as well as ‘non-market’ benefits such as climate regulation, carbon sequestration, habitat and biodiversity, among many others . And yet, its health is failing. Surely there must be no doubt in anyone’s mind that our health will also suffer too as a consequence.