Although humans cannot live in the ocean, without it we would not be able to live on earth. The ocean makes up 71% of the Earth’s surface and 80% of all life is contained there. It regulates the climate and absorbs nearly one-third of human-caused carbon dioxide emissions. It provides over half of the planet’s oxygen and regulates the earth’s weather which in turn provides us with fresh drinking water.
Much of our food is provided by the sea and fish is a very important source of food security, particularly for the poorest in society. The ocean is a lifeline when we get hit by drought and it contains the only food not dependent on freshwater. According to the UN, the ocean is the largest source of protein on earth and approximately 2.6 billion people rely on marine life as their primary protein source.
The ocean provides much of the medicine to help fight cancer, heart disease and viruses. It promotes psychological well being and provides opportunities for recreation.
Over 3 billion people on earth directly depend on marine life for their livelihoods. According to the UN, the market value of ocean and coastal resources and industries is estimated at US$3 trillion per year or 5% of global GDP. In Namibia, the fishing industry alone provides direct employment of around 13,380 people and contributes $4.8 billion in foreign currency earnings and approximately 5% of Namibia’s total Gross Domestic Product.
In total, all the natural resources and services the ocean provides for free is worth about US$21 trillion annually. Yet, even though it contributes so much to our well being, we know more about the moon and mars than we do our ocean. Unfortunately humans are tinkering with the delicate balance of the ocean that we know very little about. We have only explored 5% of it, yet 40% of the ocean is negatively affected by us. Pollution, mining, oil exploration and development, and overfishing are the main drivers to the demise of the sea.
One of the worst human impacts on the ocean is pollution. The main cause of marine pollution is the use and production of the fertilizers nitrogen and phosphorous (phosphate). Sewage, solid waste, vehicular and industrial emissions only compound the problem. The result is that there are now 405 dead zones in our planet’s ocean caused by pollution. These areas are so toxic that virtually no life except algae and bacteria exists there.
Only 4% of these dead zones are showing any sign of recovery and most are only getting larger. The largest dead zone in our ocean is 70,000 square kilometres. Global warming will only lead to the increase in dead zones. If we stay on the present course, it is predicted that more than a fifth of the world’s ocean may become a dead zone.
Now more than ever, we need to proceed with caution on how we treat our ocean, not only for the wellbeing of marine life, but for our very survival which intricately depends on the health of the ocean.