Airweed was a plant found in the Fields of Air near the island of Mahri Nui with air trapped inside of it. When Mahri Nui fell from above after breaking off of Voya Nui, it landed near the Fields of Air, disturbing the airweed and causing them to release many bubbles, forming an air bubble around the entire island. Local Matoran began taming Hydruka, stubborn sea Rahi that could naturally sense which plants in the Fields of Air were airweed and which ones were normal seaweed. They supervised the Hydruka during the safe hour as they harvested airweed, and they used the air to reinforce the bubble around Mahri Nui and for use as their own personal air bubbles. Some Matoran, such as Dekar, used the air bubbles as weapons. They loaded the bubbles into shoulder-mounted air bubble launchers and fired them at intruders.