Oceans cover more than 70% of the Earth and are the source of vital resources including food, freshwater, and oxygen. They are also important for recreation, economic development, and a stable climate. The oceans provide an unimaginable array of biological diversity and habitats, containing more than 100 million species of plants and animals. Many are critically endangered. In addition, oceans act as a natural buffer for climate change and are a key part of the global water cycle.
Scientists are still learning about the vast, interconnected system of oceans and seas. We know much more than we used to about the depths and currents of the ocean, but our understanding of its ecosystem is only beginning to be tapped. We don’t yet fully know how oceans work, whether we are approaching critical tipping points, or the extent of our impact on the ocean.
There is growing recognition that on our blue planet — over two-thirds of which is covered in water — it’s the oceans that truly deserve to be called the lungs of the world. They produce 50 to 80 percent of the oxygen we breathe through a process called photosynthesis performed by marine plants such as phytoplankton and algae. They are a primary food source for 3 billion people globally. And they are an essential carbon sink, absorbing about half of the carbon dioxide humans release into the atmosphere each year.
Scientists have begun to understand the role of oceans in regulating climate and creating weather. They are able to do this through ocean currents, which circulate warm waters from the equator and colder waters from the poles, regulating global temperatures and counteracting uneven distribution of sunlight. Without this energy regulation, the world would be too hot to sustain life.
Oceans are also an important economic resource, providing a large portion of the world’s fish, oil, and minerals. They are also important for transportation and trade, forming major shipping routes for goods and services. Ports, which are densely populated with businesspeople who import and export goods, workers who load and unload cargo, and ship’s crews, bring together a diversity of cultures, languages, and religions.
One of the biggest challenges facing oceans is the amount of pollution they contain, largely from land-based sources. Plastics, chemicals, pesticides, and untreated sewage are among the many threats that are harming the health of the ocean. These pollutants are being carried into the ocean by rivers and streams and can have a profound effect on the health of organisms in the sea, including fish and shellfish.
Being by the sea has long been thought to have a positive effect on human health. In fact, there is a growing body of evidence that shows the ocean can improve our mental and physical wellbeing. Researchers have found that simply being in the ocean can help you to be more mindful and reduce stress and anxiety levels. This is because being in the ocean requires your full attention and can help you to feel a sense of awe, which has been shown to have powerful psycho-emotional benefits.