Thursday 6 April 2023 - Discovery of a new oasis in the deep!

When we look at the earth from space, about 70% of the earth is covered by oceans and seas. The largest part (91%) of these oceans is characterized as deep sea, which is defined as all depths deeper than 200 m water depth. Only 7% of the deep sea so far has been explored by humans and therefore the deep sea can be considered the largest wilderness on earth. Even though the pressure is immense, and it is a cold, dark, and food deprived environment, the deep sea is teeming with life hosting unknown diversity. As we explore the deep sea with our cameras, we are true explorers, since we are the first to have a look at these mysterious parts of the ocean.

Cold-water coral reefs form habitats for a diverse faunal community

During the OASIS cruise, awarded to ICM CSIC by Eurofleets+, we are exploring a little part of this wilderness in the Alboran sea in the westernmost part of Mediterranean Sea. In the Alboran Sea two large banks are found that rise 300 meters above the seafloor and during a previous cruise a thriving and large cold-water coral reef was observed on one of these. This cruise we have visited the other “twin” bank with a remotely operated vehicle equipped with cameras and when diving down we found a dense cover of living corals and sponges on top of the bank. Another amazing new discovery of a deep-sea reef!

Thriving Lophelia reef on top of the Gatifas Bank

The cold-water coral reefs and sponge grounds form important habitats for many other species that use the reefs as nursery, place to shelter or feed. In the coming days we are going to further explore these oases in the deep sea using state of the art instruments to determine their biodiversity and measure the environmental conditions to ultimately answer the question why they thrive in these peculiar areas. OASIS findings will also have important implications in defining imminent environmental policies to protect the explored reefs from threatening human activities.

Sponge ground of Asconema sp.