#DidYouKnow! Until 2018 the largest dead zone was supposed to be in Gulf of Mexico. The recent study led the discovery of this new finding in the Arabian sea. The Gulf of Oman connects the Arabian Sea to the Persian Gulf, covering 70,000 square miles (181,000 square kilometres). An area of geopolitical importance and with low focus on scientific exploration, it is not surprising that far less attention has been given to this threat to the oceans and the planet itself!
Dead zones are low-oxygen, or hypoxic, areas in the world’s oceans and lakes. Less oxygen dissolved in the water is often referred to as a “dead zone” because most marine life either dies, or, if they are mobile such as fish, leave the area. Habitats that would normally be teeming with life become, essentially, biological deserts. When nutrient-fueled algae blooms die and decompose, the resulting low-oxygen conditions—known as “dead zones”—can suffocate underwater life and shrink available habitat.
There can be hypoxic zones in the environment naturally, but the places that have been aggravated or formed by human activities are of concern to scientists. Nutrient pollution is the main reason for human-made dead zones, while other physical, chemical, and biological elements also contribute to their creation. Excess nutrients that are dumped into rivers and beaches as wastewater or that flow off the land can promote an overgrowth of algae, which sinks and decomposes in the sea. Healthy marine life cannot survive on the amount of oxygen being consumed by the breakdown process.
Oceans are a delicate ecosystem with complex interactions and life cycles across a host of organisms. National Geographic Society data indicates that in 2021, "Dead Zones" numbered 415 worldwide. It is a crying need to mitigate the adverse impact and progress to reducing these. What can be done?
As individuals and even as single institutions one may feel powerless to tackle a crisis like increasing "Dead Zones" due to climate change, there are initiatives that are possible. Control of quantum of nutrient pollution entering the oceans is feasible and will reduce the pace of climate change. Every venture, family or institution that produces effluents that finally run off to the seas can take simple measures build things like a a rain garden or rain barrel to capture and absorb rainfall. This has been tried in Chesapeake Bay in Virginia, USA. Technological solutions like pumping oxygen rich surface water into the depth of a "Dead Zone" have been suggested as an option. Segregation and better management of trash along with reduce, reuse and recycle are options that have indirect and yet significant benefits to mitigate ocean pollution.
Oceans are the source and sustenance of life. We may not be able to do much to reverse the ongoing crisis, but we can raise awareness to reclaim our planet which is 71% Ocean!