Organized patches of bioherm growth where the Strait of Dardanelles enters the Marmara Sea, Turkey

The bioherms occur at depths between − 30 m and − 60 m. They are absent above and below these depths. In this part of the southwestern Marmara Sea at the eastern exit of the Strait of Dardanelles, water depth controls important water mass properties such as salinity, nutrient supply and availability of light. Other inferred critical controls are the availability of a suitable hard substrate where Holocene muds are thin or absent, and nutrient supply, potentially including a component from escaping methane-rich pore fluids. Evidence here and elsewhere in the Marmara Sea provisionally dates the onset of bioherm growth and development to the latest Pleistocene-earliest Holocene, after global sealevel rose to the breach depth of the Strait of Dardanelles at ~ 13.8 cal ka.