A UN report warned Monday that the ocean is under intensifying stress, and called for urgent global collaboration to protect marine ecosystems.
Launched on World Oceans Day, which is observed annually on June 8, the third World Ocean Assessment found out that the ocean continues to be under severe and accelerating anthropogenic pressure, driven by climate change, pollution and increased human activities. These pressures are often cumulative, combining to cause widespread biodiversity loss, undermining the ecosystems that support fisheries, coastal protection and human health.
"The third World Ocean Assessment, launched today, documents a deepening crisis driven by climate change, overfishing, biodiversity loss and marine pollution," U.N. Secretary-General Antonio Guterres said in a message for the launch of the report.
"We cannot keep treating the ocean as limitless. We must build a new relationship with the ocean: Grounded in science. Framed by international law. And built on shared responsibility -- across nations, sectors, and generations -- to advance the Sustainable Development Goals," said Guterres.
The third World Ocean Assessment identified the main human drivers of change to the ocean: human population growth and demographic changes; economic activity; technological advances; changing governance structures and social, economic and geopolitical instability; and climate change, biodiversity loss and pollution.
It found that about 16 percent of the total increase in ocean heat content since 1955 has occurred since 2018. The greatest relative warming has been observed in the Atlantic Ocean and the southern parts of the Indian and Pacific Oceans.
The sea level continued to rise at increasing rates, from less than 2 millimeters per year prior to 2015 to 4.3 millimeters per year in 2023, according to the report.
Also, it found that 52.1 million tonnes of plastic waste enter the ocean each year, contributing to an estimated 24.4 trillion microplastic particles, which are now known to affect more than 4,000 marine species.
Large gaps persist in ocean knowledge, the report said, with only 27.3 percent of the seafloor mapped as of 2025, leaving deep-sea ecosystems, biological processes, and cumulative impacts poorly understood.
"The imperative for a healthy and resilient ocean has never been more urgent. Global collaborations and research, and our increased understanding of the ocean provide essential insights into the state of marine ecosystems, the profound changes they are undergoing and the need for our care," said Rafael Gonzalez-Quiros, joint coordinator of the group of experts for the third World Ocean Assessment.
UN report calls for urgent global collaboration to protect marine ecosystems
