When we think about the ocean, many of us imaginatively arrive at sun drenched waves, coral reefs, or sandy beaches. However, beneath this there is a completely different world which is so immense and dark and unexplored that scientists liken it to outer space. This curious space, dubbed the deep ocean, can be found approximately 200 meters beneath the surface, where light disappears and pressure builds to levels we cannot comprehend. While we seldom see it, the deep ocean is an integral part of the climate system on Earth, as well as supporting biodiversity and life, both above and below the waves. If we want to fully appreciate our planet, we need to realize that this amazing ecosystem exists, despite how easy it is to overlook.

Why is the deep ocean so important?

The deep ocean is one of the world’s largest habitats, but at the same time, one of the least visited one. Plants and animals living in the deep ocean endure extreme conditions temperatures near freezing, high pressures and lack of light. Many organisms have incredible adaptations bioluminescence for communication or hunting, slow metabolic rates to take advantage of limited food supplies, and specialized bodies that can withstand immense pressure that can crush submarines.

These ecosystems are also important for regulating the climate of the planet. Deep ocean circulation transports heat across the globe creating weather patterns and maintaining average temperatures. In addition, the deep ocean is a considerable carbon storage reservoir and one of the most significant “carbon sinks” on Earth. Without it, concentrations of carbon dioxide in the atmosphere would rise much faster.

Biodiversity in the deep ocean is yet another important feature. Deep sea thermal vents, trenches and seamounts contain species of plants and animals that cannot be found anywhere else on Earth. Many of these organisms have interesting biochemical compounds that could lead to new medicines or technological processes.

Sadly, the deep ocean faces growing threats. Mining for minerals, pollution, deep sea trawling, and climate change endanger fragile habitats that may take centuries to recover. Because so much of this environment is still unexplored, humanity risks damaging species and ecosystems before even discovering them.

Despite these dangers, there is hope. Modern exploration programs, advanced submersibles, and international conservation efforts are expanding our understanding of the deep. By protecting this vast and remarkable ecosystem, we safeguard not only biodiversity but the planetary systems that support all life on land and at sea.

Citations:

National Oceanic and Atmospheric Administration. (2022). Carbon storage in the deep ocean. NOAA Climate.gov. https://www.climate.gov

National Oceanic and Atmospheric Administration. (2021). Deep ocean ecosystems and biodiversity. NOAA Office of Marine and Aviation Operations. https://www.omao.noaa.gov

Smith, K. L., & DeMaster, D. J. (2020). Deep-sea ecological processes and climate connections. NOAA Ocean Science Journal. https://oceanexplorer.noaa.gov