has part adjacent to shoreline aquatic estuarine layer estuarine coastal surface layer liquid air-water interface layer estuarine coastal upper water column A layer of estuarine water which extends from the surface of the water column to the pycnocline or mid-depth and from the shore to a fiat boundary where the estuary bed below the water column reaches a depth of 4 meters. envoMarine envoCmecs "Mid-depth", present in many CMECS classes, is ambiguous and needs refinement. https://cmecscatalog.org/cmecs/classification/unit/596.html This class aligns to the Coastal and Marine Ecological Classification Standard (CMECS). In ENVO, we may adapt the definition for consistency, but the semantics (meaning) of the term should be unaffected. Please consult the CMECS catalogue (https://cmecscatalog.org/) for authoritative and semantically unconstrained definitions. CMECS:596 estuarine coastal pycnocline surface of an astronomical body