Scientists have discovered that nearly one-fifth of the global ocean has darkened over the past two decades, affecting the largest bodies of water covering our planet. This phenomenon is caused by changes in the optical properties of ocean water, resulting in less light reaching the seafloor.
According to a new study published in Global Change Biology, around 75 million square miles of the Earth’s surface have undergone this change. The research, led by scientists from the University of Plymouth and Plymouth Marine Laboratory, used satellite data and advanced numerical models to track changes in photic zones – areas where nearly 90% of ocean life resides.
The study found that large portions of open ocean and coastal waters had darkened between 2003 and 2022. Regions such as the Gulf Stream and icy polar regions have seen significant changes, while other areas like the Baltic Sea are also affected due to increased rainfall carrying nutrients and sediments into the ocean.
This phenomenon has sparked concern among scientists, who believe it could impact marine life forms and ecosystems. “The ocean is far more dynamic than it’s often given credit for,” said Professor Tim Smyth. “If the photic zone is reducing by around 50m in large swathes of the ocean, animals that need light will be forced closer to the surface where they will have to compete for food and resources.”
The study highlights the importance of monitoring changes in Earth’s oceans, which rely on the ocean and its photic zones for air we breathe, fish we eat, fighting climate change, and general health and well-being. The research team is unsure of the long-term effects of these changes but emphasizes the need for further investigation into this concerning trend.
Source: https://thedebrief.org/scientists-have-made-a-dark-discovery-about-earths-oceans-experts-call-it-a-genuine-cause-for-concern