Day 64 – Q 3. Recently a large dead zone was discovered in the Indian Ocean. What are dead zones? What can be the reasons behind the formation of dead zones?
3. Recently a large dead zone was discovered in the Indian Ocean. What are dead zones? What can be the reasons behind the formation of dead zones?
Dead zones are oxygen-starved ocean regions where few organisms can survive. They emerge in ocean depths ranging from 650 to 2,600 feet (200 to 800 meters), when influxes of chemical nutrients — typically from human pollution — spur algae growth, which sucks up oxygen. A large dead zone has been recently discovered in the Gulf of Oman.
Reasons behind the formation of dead zones:
- Climate change- Warmer ocean waters near the sea surface hamper the retention and circulation of oxygen.
- Eutrophication- An increase in chemical nutrients in the water, leading to excessive blooms of algae that deplete underwater oxygen levels.
- Algal bloom- Overgrowth of algae, which then sinks and decomposes in the water. The decomposition process consumes oxygen and depletes the supply available to healthy marine life.
- Agricultural runoff- Nitrogen and phosphorous from chemical fertilizers lead to eutrophication.
- Emissions- Sewage, vehicular and industrial emissions add to the nutrient content of ocean.
- Oceanographic phenomenon- Stagnant water in enclosed water bodies, coastal upwelling, ocean and wind current patterns effect the formation of dead zones.
Dead zones are causing a devastating effect on marine life form, lead to loss of habitat and biodiversity, as well as have social and economic implications by disrupting the fishing industry.
There is need to get all stakeholders on board to address the issue. A spur of ecofriendly activities like proper waste disposal, addressing climate change, organic farming, recycle and reuse, wetlands and floodplains conservation etc. along with new initiatives like nutrient trading on lines of carbon trading can go a long way in solving the problem.
Best answer: Sreelakshmy Vijayan Uma