EUNIS habitat type hierarchical view (marine version 2022 & terrestrial version 2021)

The EUNIS habitat classification review is on-going. Four groups are pending review: Inland waters, Wetlands, Constructed, industrial and other artificial habitats and Complexes.

• M : Marine benthic habitats (MA-MG)
  
• MH : Pelagic water column
  
  • MH1 : Neuston
    
  • MH2 : Completely mixed water column with reduced salinity
    
  • MH3 : Completely mixed water column with full salinity
    
  • MH4 : Partially mixed water column with reduced salinity and medium or long residence time
    
    • MH41 : Arctic partially mixed water column with reduced salinity and medium or long residence time
      
      • MH411 : Arctic partially mixed water column with reduced salinity and medium residence time
        
      • MH412 : Arctic partially mixed water column with reduced salinity and long residence time
        
    • MH42 : Atlantic partially mixed water column with reduced salinity and medium or long residence time
      
    • MH43 : Baltic partially mixed water column with reduced salinity and medium or long residence time
      
    • MH44 : Black Sea partially mixed water column with reduced salinity and medium or long residence time
      
      • MH441 : Black Sea partially mixed water column with reduced salinity and medium residence time
        
      • MH442 : Black Sea partially mixed water column with reduced salinity and long residence time
        
    • MH45 : Mediterranean partially mixed water column with reduced salinity and medium or long residence time
      
  • MH5 : Unstratified water column with reduced salinity
    
  • MH6 : Vertically stratified water column with reduced salinity
    
    • MH61 : Arctic vertically stratified water column with reduced salinity
      
    • MH62 : Atlantic vertically stratified water column with reduced salinity
      
    • MH63 : Baltic vertically stratified water column with reduced salinity
      
    • MH64 : Black Sea vertically stratified water column with reduced salinity
      
    • MH65 : Mediterranean vertically stratified water column with reduced salinity
      
      • MH651 : Mediterranean water column with ephemeral thermal stratification and reduced salinity
        
      • MH652 : Mediterranean water column with seasonal thermal stratification and reduced salinity
        
      • MH653 : Mediterranean water column with permanent thermal stratification and reduced salinity
        
      • MH654 : Mediterranean water column with ephemeral halocline and reduced salinity
        
      • MH655 : Mediterranean water column with seasonal halocline and reduced salinity
        
      • MH656 : Mediterranean water column with permanent halocline and reduced salinity
        
      • MH657 : Mediterranean water column with ephemeral oxygen stratification and reduced salinity
        
      • MH658 : Mediterranean water column with seasonal oxygen stratification and reduced salinity
        
      • MH659 : Mediterranean water column with permanent oxygen stratification and reduced salinity
        
  • MH7 : Fronts in reduced salinity water column
    
  • MH8 : Unstratified water column with full salinity
    
    • MH81 : Arctic unstratified water column with full salinity
      
      • MH811 : Arctic euphotic (epipelagic) zone in unstratified full salinity water
        
      • MH812 : Arctic mesopelagic zone in unstratified full salinity water
        
      • MH813 : Arctic bathypelagic zone in unstratified full salinity water
        
      • MH814 : Arctic abyssopelagic zone in unstratified full salinity water
        
    • MH82 : Atlantic unstratified water column with full salinity
      
    • MH83 : Baltic unstratified water column with full salinity
      
    • MH84 : Black Sea unstratified water column with full salinity
      
    • MH85 : Mediterranean unstratified water column with full salinity
      
  • MH9 : Vertically stratified water column with full salinity
    
  • MHA : Fronts in full salinity water column
    
    • MHA1 : Arctic fronts in full salinity water column
      
    • MHA2 : Atlantic fronts in full salinity water column
      
    • MHA3 : Baltic fronts in full salinity water column
      
    • MHA4 : Black Sea fronts in full salinity water column
      
    • MHA5 : Mediterranean fronts in full salinity water column
      
• MJ : Ice-associated marine habitats
  
  • MJ1 : Sea ice
    
  • MJ2 : Freshwater ice
    
  • MJ3 : Brine channels
    
  • MJ4 : Under-ice habitat
    
• N : Coastal habitats
  
  • N1 : Coastal dunes and sandy shores
    
  • N2 : Coastal shingle
    
  • N3 : Rock cliffs, ledges and shores, including the supralittoral
    
• Q : Wetlands
  
• R : Grasslands and lands dominated by forbs, mosses or lichens
  
• S : Heathland, scrub and tundra
  
• T : Forest and other wooded land
  
• U : Inland habitats with no or little soil and mostly with sparse vegetation
  
  • U1 : Terrestrial underground caves, cave systems, passages and waterbodies
    
    • U11 : Cave
      
      • U111 : Troglobiont vertebrate caves
        
      • U112 : Subtroglophile vertebrate caves
        
      • U113 : Troglobiont invertebrate caves
        
      • U114 : Troglophile invertebrate caves
        
      • U115 : Subtroglophile invertebrate caves
        
      • U116 : Caves without vertebrates or invertebrates
        
      • U117 : Lava tubes
        
    • U12 : Disused underground mines and tunnels
      
  • U2 : Screes
    
  • U3 : Inland cliffs, rock pavements and outcrops
    
  • U4 : Snow or ice-dominated habitats
    
  • U5 : Miscellaneous inland habitats usually with very sparse or no vegetation
    
  • U6 : Recent volcanic features
    
• V : Vegetated man-made habitats