Free-living mesophotic Foraminiferal-Algal Nodules (FANs) have been discovered along the coast of the northern Saudi Arabian Red Sea (NEOM region) where they form a novel benthic ecosystem in mesophotic water depths on the continental shelf. Being mostly spheroidal, the nodules are transported en masse down slope, into the deep water of the basin, where they stop accreting. Radiometric dating informs that FANs can be more than two thousand years old and that they collectively contribute up to 66 g m-2 year-1 to the mesophotic benthic carbonate budget and account for at least 980 megatons of CaCO3, a substantial contribution considering the depauperate production of carbonate by other means in this light-limited environment. Our findings advance the knowledge of mesophotic biodiversity and carbonate production, and provide data that will inform conservation policies in the Saudi Arabian Red Sea.
|Date made available||Aug 16 2023|