Scientists have warned that the deepest parts of our oceans that receive sunlight could see a significant reduction in life due to climate change. Researchers have predicted that global warming could cause a decline in life in the twilight zone of the ocean, situated between 200 meters (656 feet) and 1,000 meters (3,281 feet), by up to 40% by the end of the century. This crucial habitat for marine life is home to a diverse range of species, including plankton, jellies, and microbes, and too dim for photosynthesis to occur, but it has more fish than the rest of the ocean combined, making it an essential carbon sink, drawing carbon out of the atmosphere.
The researchers studied two warm periods in the Earth’s past, around 50 million years ago and 15 million years ago, and discovered that fewer organisms lived in the twilight zone during these periods. The team found that bacteria degraded food more quickly, meaning less of it reached the twilight zone from the surface. The researchers simulated current and future changes in the twilight zone due to climate warming, suggesting that significant changes may already be underway.
The lead author of the study, Dr Katherine Crichton, from the University of Exeter, explained that the rich variety of twilight zone life evolved when ocean waters had cooled, allowing for the preservation of food and improved conditions for life to thrive. However, unless greenhouse gas emissions are reduced quickly, there could be disastrous consequences for the twilight zone, with the disappearance or extinction of much of the zone’s life within 150 years. The study emphasizes the need for urgent action to combat climate change to preserve the crucial marine life in the twilight zone, which plays a crucial role in the health of our oceans and the planet as a whole.
The study, published in the journal Nature Communications, is a significant step forward in our understanding of how vulnerable the ocean’s twilight zone is to climate change. The research highlights the importance of protecting our oceans and taking action to reduce greenhouse gas emissions to avoid catastrophic consequences for marine life and the environment.
