Intertidal
The area of the shore that is covered by water at high tide and exposed to air at low tide.
Invertebrate
An animal that doesn’t have a backbone, such as insects, spiders, worms, crabs and slugs.
Infiltration
The natural passage of rain into the soil where it falls.
Irreplaceable habitat
Irreplaceable habitat, if destroyed, is very difficult (or takes a significant time) to restore, recreate or replace because of its age, uniqueness, species diversity or rarity.
IUCN
International Union for Conservation of Nature