Our oceans cover around 70 percent of the Earth’s entire surface, they are essential ecosystems and true hotspots of biodiversity. Our oceans are home to an astonishing amount of life, much of which is still undiscovered by science. For example, we already know more about the surface of the moon than we do about the deep sea.
What the oceans do for the planet and for us
Protecting our oceans is an important part of nature conservation. Animals and plants in the oceans bind large amounts of carbon and therefore have a buffer function for the Earth’s CO2 balance. The oceans absorb around 50 times as much carbon as the atmosphere. The global climate balance is therefore largely determined by the water masses in the oceans. The sea supplies us with water and oxygen and is also the largest source of food worldwide, as billions of people feed on marine animals.
What is endangering our oceans?
Consequences of the climate crisis
Our oceans therefore absorb enormous amounts of CO2 and store roughly the same amount of carbon dioxide as plants on land. Due to climate change, temperatures are rising and there is therefore a risk that oceans will no longer be able to absorb and store as much CO2 in the future. In addition, changes in winds due to climate change are also influencing ocean circulation. As a result, deep water is increasingly rising to the surface, meaning that less CO2 can be absorbed.
Another consequence of climate change is the so-called acidification of the oceans. This changes the pH value of the seawater, which in turn can impair the growth and reproductive capacity of living organisms. This is often referred to as “coral death”: animals with calcareous shells and skeletons are particularly affected by this change. However, plankton, which forms the basis of the food web, is also affected by acidification.
The global climate system reacts slowly and so a rise in sea level is to be expected even if CO2 emissions are limited. This means that many coastal inhabitants around the world will be affected by storm surges and flooding. The melting of glaciers will further accelerate sea level rise.
Consequences of plastic pollution and fishing
Oceans are also affected by declining oxygen levels in the water, pollution from vast amounts of plastic waste and overfishing by global fisheries. Larger marine mammals in particular, such as whales, dolphins and sea turtles, are endangered by plastic pollution. Microplastics also find their way into the environment and therefore into the sea via various routes, as we have already reported in this article. The plastic floating in the sea forms into huge plastic swirls, such as the well-known “Great Pacific Garbage Patch” in the Pacific, and attracts many bacteria and environmental toxins.
What we can do for our oceans
The climate crisis, pollution from plastic waste, oil drilling, shipping traffic and numerous other developments are endangering biodiversity and leading to far-reaching changes in our oceans. Without far-reaching protective measures, large parts of our oceans could become uninhabitable.
The preservation of the oceans depends, among other things, on how much CO2 mankind will emit in the future and whether the establishment of protected areas will be successful. Marine protected areas are an effective tool to protect the oceans from harmful influences and to implement sustainability goals in the oceans. In the next five years, i.e. by 2030, at least 30 % of the oceans should be designated as protected areas. However, we also need to use our oceans in a sustainable way by consuming less fish, supporting sustainable fishing and banning disposable plastic. If you would like to find out more about sustainable fish consumption, you can find useful information and tips in the current WWF fish guide for Austria.