has part composed primarily of fresh water estuarine open water upper water column estuarine tidal riverine open water surface layer estuarine tidal riverine open water upper water column https://cmecscatalog.org/cmecs/classification/unit/608.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. "Mid-depth", present in many CMECS classes, is ambiguous and needs refinement. What causes this freshwater layer to be "tidal" is not clearly specified in the current CMECS definition. A layer of fresh, tidal estuarine water which extends from the surface of the water column to the pycnocline or mid-depth and from a fiat boundary where the estuary bed below the water column reaches a depth of 4 meters until the end of the estuary most distal from the coast. envoCmecs envoMarine CMECS:608