A recent study published in Global Change Biology has found that more than a fifth of the global ocean has become darker over the past two decades, raising concerns about the impact on marine ecosystems and human societies.
Researchers at the University of Plymouth discovered that 21% of the ocean had become darker between 2003 and 2022 due to changes in algal bloom dynamics, sea surface temperatures, and artificial light. This phenomenon, known as “ocean darkening,” reduces the depth at which sunlight can travel, affecting marine species and ecosystem services.
The study found that over 9% of the ocean had seen a reduction in light by more than 164ft (50m), while an additional 2.6% had experienced a reduction of more than 328ft (100m). The researchers warn that these changes could have significant implications for large numbers of marine species and ecosystem services.
Dr. Thomas Davies, associate professor of Marine Conservation at the University of Plymouth, states that ocean darkening could affect the air humans breathe, the fish they eat, and our ability to fight climate change. He emphasizes that this finding represents a genuine cause for concern.
The study’s findings also suggest that some marine animals may be forced closer to the surface as a result of the changes, leading to increased competition for food and resources. This could bring about fundamental changes in the entire marine ecosystem.
As the research highlights, ocean darkening is a pressing issue that warrants attention and action from policymakers and the scientific community alike.
Source: https://www.bbc.com/news/articles/c23m1018dkmo