| A1 : Littoral rock and other hard substrata |
| A2 : Littoral sediment |
| A2.3 : Littoral mud |
| A3.1 : Atlantic and Mediterranean high energy infralittoral rock |
| A3.2 : Atlantic and Mediterranean moderate energy infralittoral rock |
| A3.3 : Atlantic and Mediterranean low energy infralittoral rock |
| A4.1 : Atlantic and Mediterranean high energy circalittoral rock |
| A4.2 : Atlantic and Mediterranean moderate energy circalittoral rock |
| A4.3 : Atlantic and Mediterranean low energy circalittoral rock |
| A5.13 : Infralittoral coarse sediment |
| A5.14 : Circalittoral coarse sediment |
| A5.15 : Deep circalittoral coarse sediment |
| A5.23 : Infralittoral fine sand |
| A5.24 : Infralittoral muddy sand |
| A5.25 : Circalittoral fine sand |
| A5.26 : Circalittoral muddy sand |
| A5.27 : Deep circalittoral sand |
| A5.33 : Infralittoral sandy mud |
| A5.34 : Infralittoral fine mud |
| A5.35 : Circalittoral sandy mud |
| A5.36 : Circalittoral fine mud |
| A5.37 : Deep circalittoral mud |
| A5.43 : Infralittoral mixed sediments |
| A5.44 : Circalittoral mixed sediments |
| A5.45 : Deep circalittoral mixed sediments |