| Feature | Definition |
|---|---|
| Coastal water setting | Coastal zone from supra-littoral to 6 m depth. Note the CMECS definition is 4 m depth – this was changed to be consistent with mapping Ramsar sites. Note this overlaps with the EUNIS Level 1 Coastal Environment class, which is landward from the littoral zone, and includes the supralittoral zone. |
| Estuarine setting | Tidally influenced waters regularly diluted by freshwater. Tidal influence may be restricted to saline bottom waters overlain by fresh surface waters in strongly stratified estuaries. |
| Marine setting | Waters with salinity typically 35 PSU. |
| Marine nearshore setting | Supralittoral to 30 m depth, salinity typically 35 PSU. Note the CMECS 30 m depth division between nearshore and offshore settings does not necessarily align with the JNCC infralittoral and circalittoral divisions, which are based on the depth of the euphotic zone. |
| Marine offshore setting | Sublittoral zone from 30 m depth to the shelf break. Note the CMECS 30 m depth division between nearshore and offshore settings does not necessarily align with the JNCC infralittoral and circalittoral divisions, which are based on the depth of the euphotic zone. |
| Marine oceanic setting | Shelf break to continental slope and beyond to abyssal zone (4000-6000 m). |
| Open water setting | Waters not adjacent to the shore, from a depth of 6 m depth and salinity typically 35 PSU. Note the CMECS definition is 4 m depth – this was changed to be consistent with mapping Ramsar sites. |
| Tidal riverine | Tidal freshwater with salinity < 0.5 PSU. |
