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
    
    • MH21 : Arctic completely mixed water column with reduced salinity
      
      • MH211 : Arctic completely mixed water column with reduced salinity and short residence time
        
      • MH212 : Arctic completely mixed water column with reduced salinity and medium residence time
        
      • MH213 : Arctic completely mixed water column with reduced salinity and long residence time
        
    • MH22 : Atlantic completely mixed water column with reduced salinity
      
    • MH23 : Baltic completely mixed water column with reduced salinity
      
    • MH24 : Black Sea completely mixed water column with reduced salinity
      
    • MH25 : Mediterranean 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
    
  • MH5 : Unstratified water column with reduced salinity
    
    • MH51 : Arctic unstratified water column with reduced salinity
      
    • MH52 : Atlantic unstratified water column with reduced salinity
      
      • MH521 : Atlantic euphotic (epipelagic) zone in unstratified reduced salinity water
        
      • MH522 : Atlantic mesopelagic zone in unstratified reduced salinity water
        
      • MH523 : Atlantic bathypelagic zone in unstratified reduced salinity water
        
      • MH524 : Atlantic abyssopelagic zone in unstratified reduced salinity water
        
    • MH53 : Baltic unstratified water column with reduced salinity
      
    • MH54 : Black Sea unstratified water column with reduced salinity
      
    • MH55 : Mediterranean unstratified water column with reduced salinity
      
  • MH6 : Vertically stratified water column with 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
      
      • MHA11 : Arctic ephemeral fronts in full salinity water column
        
      • MHA12 : Arctic seasonal fronts in full salinity water column
        
      • MHA13 : Arctic persistent fronts in full salinity water column
        
    • MHA2 : Atlantic fronts in full salinity water column
      
      • MHA21 : Atlantic ephemeral fronts in full salinity water column
        
      • MHA22 : Atlantic seasonal fronts in full salinity water column
        
      • MHA23 : Atlantic persistent fronts in full salinity water column
        
    • MHA3 : Baltic fronts in full salinity water column
      
      • MHA31 : Baltic ephemeral fronts in full salinity water column
        
      • MHA32 : Baltic seasonal fronts in full salinity water column
        
      • MHA33 : Baltic persistent fronts in full salinity water column
        
    • MHA4 : Black Sea fronts in full salinity water column
      
      • MHA41 : Black Sea ephemeral fronts in full salinity water column
        
      • MHA42 : Black Sea seasonal fronts in full salinity water column
        
      • MHA43 : Black Sea persistent fronts in full salinity water column
        
    • MHA5 : Mediterranean fronts in full salinity water column
      
• MJ : Ice-associated marine habitats
  
• N : Coastal habitats
  
• 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
    
  • 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