Scientists warn ocean is losing oxygen as El Niño cooks Pacific

A new study warns that the world's oceans are rapidly losing oxygen, a trend that scientists say could destabilize the planet. The research, highlighted in reports from SFGATE, Gizmodo, Oceanographic Magazine, newsreel.com.au, and ScienceDaily, finds that oxygen levels in Earth's waters are declining at an alarming rate, driven primarily by climate change and nutrient pollution.

The loss of oxygen affects marine ecosystems globally, threatening fish populations and the livelihoods of billions who depend on the ocean for food and income. As the Pacific Ocean warms due to El Niño, the problem intensifies, with California scientists among those raising the alarm. The phenomenon, known as deoxygenation, creates dead zones where most marine life cannot survive.

This matters because oxygen loss in the ocean can disrupt the entire marine food web, potentially leading to mass die-offs and economic losses in fishing industries. The study indicates that the rate of oxygen decline is accelerating, pushing Earth into what some researchers describe as 'unsafe space' for humanity.

Specific numbers from the source include that oxygen levels have dropped by about 2% globally since the 1950s, and the volume of oxygen-depleted waters has increased more than fourfold. The research draws on decades of data from ocean monitoring stations worldwide.

Background: Scientists have long warned that warming waters hold less oxygen, and that agricultural runoff fuels algae blooms that consume oxygen when they decompose. The new study synthesizes these findings to show the cumulative impact.

Next steps: Researchers call for urgent reductions in greenhouse gas emissions and nutrient pollution to slow the trend. Without action, they predict continued oxygen loss will cause widespread ecological and economic damage.