Mass extinction in the ocean: nearly half of a species is on the brink of extinction.

For years, scientists have warned about the consequences of the climate crisis, and now we are reaping its effects. The world has already faced unprecedented heat waves and droughts, both on land and in the ocean — with human activity and the greenhouse gases it produces being identified as the primary cause of global warming, reports Science Alert.

It is no secret that the brunt of the impact is borne by the world's oceans — they have absorbed around 90% of the excess heat in the atmosphere due to carbon dioxide emissions and other greenhouse gases. Furthermore, some studies indicate that the ocean is now saturated and could release all the absorbed oxygen back at any moment.

At the same time, the rise in ocean temperatures has led to widespread coral bleaching across the globe, threatening vital ecosystems for marine life. Scientists have presented an updated assessment of the IUCN Red List of endangered species, and unfortunately, the results are not encouraging.

Research indicates that nearly half of all warm-water coral species — around 44% — are currently just a step away from extinction, primarily due to rising ocean temperatures. Analysis has shown that 892 species of reef-building corals are now considered endangered, which represents 44% of the total.

Researchers note that this marks a significant increase compared to the last assessment conducted in 2008, when one-third of all species were at risk. It is important to mention that the 44% figure does not provide the complete picture, as scientists are still assessing the extinction risks for cold-water corals that inhabit deeper and darker areas of the ocean, making them harder to study.

According to IUCN Director General Grethel Aguilar, she and her colleagues are urging the world to rapidly reduce fossil fuel use, which is heating the planet. One of the arguments is that healthy marine ecosystems, including coral reefs, are essential not only for ocean inhabitants but also for humans. These ecosystems provide food for humanity, stabilize shorelines, and store carbon.

Researchers point out that coral reefs today are suffering not only from warming; other contributing factors include:

• pollution;
• disease;
• unsustainable fishing;
• agricultural runoff.

The majority of reef-building corals are found in the Indo-Pacific region, such as the Great Barrier Reef in Australia, which this year experienced one of the most severe bleaching events.

A new study by scientists also revealed that nearly one in three species of Atlantic corals is currently on the brink of extinction. This is significantly higher than previously thought. Staghorn and Elkhorn corals have been cited as examples of two critically endangered species in the Caribbean that have suffered greatly from rising water temperatures, pollution, and hurricanes.