'Dead zones' spread across oceans

A study recently published in Science magazine shows that many seas around the world are in an alarming state, with no living creatures left.

According to measurements, over the past half century, the oceans have lost about 2% of their total dissolved oxygen. This directly affects the lives of marine life.

Dead zones (marked in red or blue) are spreading across the ocean (red: coastal areas; blue: offshore) - image provided by the research team

That 2% figure is equivalent to a fourfold increase in the total volume of oxygen-free ocean water, and a tenfold increase in dead zones with low oxygen concentrations that are unsuitable for life.

The study was conducted by a team of scientists from GO2NE - the Ocean Oxygen Network, a special working group established by the United Nations. According to Dr. Denise Breitburg, a marine ecologist at the Smithsonian Environmental Research Center (USA), the decline in oxygen in the ocean is one of the most serious impacts of human activities on the Earth's living environment.

The main causes of dead zones are environmental pollution and climate change.

Pollution is one of the reasons for the spread of dead zones. In the picture: the Caribbean Sea is drowning in waste.

But while the numbers are dire, there are ways to address them. For example, a push to invest in better wastewater treatment technology in the Chesapeake Bay has led to a significant increase in the oxygen levels in the waters there. Of course, local action alone cannot save the ocean. Scientists are calling for a global effort to address this urgent problem.