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
    
    • MH31 : Arctic completely mixed water column with full salinity
      
    • MH32 : Atlantic completely mixed water column with full salinity
      
    • MH33 : Baltic completely mixed water column with full salinity
      
    • MH34 : Black Sea completely mixed water column with full salinity
      
    • MH35 : Mediterranean 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
      
      • MH511 : Arctic euphotic (epipelagic) zone in unstratified reduced salinity water
        
      • MH512 : Arctic mesopelagic zone in unstratified reduced salinity water
        
      • MH513 : Arctic bathypelagic zone in unstratified reduced salinity water
        
      • MH514 : Arctic abyssopelagic zone in unstratified reduced salinity water
        
    • MH52 : Atlantic unstratified water column with reduced salinity
      
    • 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
      
      • MH551 : Mediterranean euphotic (epipelagic) zone in unstratified reduced salinity water
        
      • MH552 : Mediterranean mesopelagic zone in unstratified reduced salinity water
        
      • MH553 : Mediterranean bathypelagic zone in unstratified reduced salinity water
        
      • MH554 : Mediterranean abyssopelagic zone in unstratified reduced salinity water
        
  • MH6 : Vertically stratified water column with reduced salinity
    
  • MH7 : Fronts in reduced salinity water column
    
    • MH71 : Arctic fronts in reduced salinity water column
      
    • MH72 : Atlantic fronts in reduced salinity water column
      
      • MH721 : Atlantic ephemeral fronts in reduced salinity water column
        
      • MH722 : Atlantic seasonal fronts in reduced salinity water column
        
      • MH723 : Atlantic persistent fronts in reduced salinity water column
        
    • MH73 : Baltic fronts in reduced salinity water column
      
    • MH74 : Black Sea fronts in reduced salinity water column
      
    • MH75 : Mediterranean fronts in reduced salinity water column
      
  • MH8 : Unstratified water column with full salinity
    
  • MH9 : Vertically stratified water column with full salinity
    
  • MHA : Fronts in full salinity water column
    
• MJ : Ice-associated marine habitats
  
  • MJ1 : Sea ice
    
    • MJ11 : Arctic sea ice
      
    • MJ12 : Baltic sea ice
      
  • MJ2 : Freshwater ice
    
  • MJ3 : Brine channels
    
  • MJ4 : Under-ice habitat
    
    • MJ41 : Arctic under-ice habitat
      
      • MJ411 : Arctic under-ice habitat in first-year ice
        
      • MJ412 : Under-ice habitat in multi-year ice
        
    • MJ42 : Baltic under-ice habitat
      
• N : Coastal habitats
  
• 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
    
  • 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