Can saltwater from the ocean be used to put out wildfires?
Yes, but there may be consequences for plant life.
Yes, salt water can be used to put out wildfires. However, salt water can harm plant life: some species are sensitive to salinity levels. Thus, using salt water may not be a wise first choice in firefighting methods in certain environments.
It can also be impractical to use saltwater, if the fires occur far from the coast.
Helicopters grabbing ocean water to fight fires: