The oceans on Earth supply oxygen, support marine life and are a key facet to the overall health of the planet. One threat to many oceans around the world is a condition called hypoxia, which leads to areas known as ocean deserts or dead zones.
Hypoxia refers to a deficient or depleted amount of oxygen in an area of water bodies. The danger of this condition is that without early detection or monitoring, ocean deserts can easily take over a particular ecosystem. Ocean deserts do not contain enough oxygen for marine plant and animal life to exist. Thus, it is not uncommon to witness large-scale fish die-off events, which are devastating to marine ecosystems as a whole.
This process can happen fairly rapidly or slowly and is greatly influenced by seasonal changes and the balance between oxygen input from the atmosphere and certain biological and chemical processes, some of which produce oxygen while others consume it. Another main cause is when nutrient cycling fails due to unequal mixing of surface water and more saline bottom waters. Other factors that speed up the formation of ocean deserts are algal growth and pollution.
Pollution that causes ocean deserts is known as nutrient pollution or eutrophication. More specifically, this nutrient pollution looks like an influx of phosphorus and nitrogen too great for an ecosystem to utilize and balance on its own. This happens through many avenues, but most commonly occurs through agricultural runoff, the burning of fossil fuels, and wastewater treatment effluent. These are mostly human-caused pollutants that have severe environmental effects on ocean systems and wildlife.
While the consequences of ocean deserts are severe, there are possible solutions that organizations, businesses, and scientists around the world continue to study. Some solutions include assisting the nutrient cycling process in areas prone to desertification, by using technologies to help mix surface waters with deeper, more saline waters.
Reducing dead zones by keeping fertilizers out of coastal waters is a manageable goal shared by both conservationists and farmers. Climate change and warming water contribute much to the acceleration of ocean deserts, and warmer waters contain less oxygen, making the cycling of nutrients that much more important. Over-exploitation of marine species as well as habitat loss are also elements of this issue that are perpetuated by human activity. This is both good and bad news, as we have both the power to remedy the situation, as well as create further damage.
Organizations, businesses, and governments must work together to minimize ocean deserts around the world.