Mesophotic reef geomorphology categorization, habitat identification, and relationships with surface cover and terrace formation in the Gulf of Aqaba

Antecedent topography such as relic reef terraces well biogenic carbonate relief-forming deposits ~30–150 m deep, referred to mesophotic reefs, provide structural support for diverse coral ecosystems (MCEs) that may serve refuges select light-dependent species. Although at depths are found globally, an understanding of their spatial distribution, formation, and relationship with living community composition lithology is generally lacking. Herein, 2 × resolution bathymetry from the Gulf Aqaba (GoA) was examined define geomorphology features spanning compare relationships overlying benthic lithologic cover. Analysis led production a new map categorizing 12 features, including upper harboring thriving MCEs. Additionally, large collection still imagery (1726 pictures) obtained 94 sites used eight unique habitats lithological biological distribution patterns over vertical horizontal scales. Study area cover be significantly different between related GoA seafloor depth slope, light attenuation. While these indicated modern could not model producing most underlying in study area, results provided data needed enhance feature formation history accretion depths. also detailed critical better identifying mapping unknown MCE habitats, recognizing biodiversity GoA. These especially important considering northern reefs act potential refuges, but local anthropogenic development continually stresses shallow other around globe continue degrade. • A created Aqaba. Eight useful future management, were identified. Mesophotic likely least 13.8% area. Depth variable partially explains factored by geomorphology. Benthic/lithologic mainly does model.