WATCH: Plane drops thousands of fish to stock mountain lakes
Since 1956, hundreds of remote lakes in Utah in the United States have been stocked by airdropping fish from planes.
This method is said to be less stressful for the fish and takes less time than transporting them by road.
According to a blog on the Utah Division of Wildlife Resources website, this was mainly done on horseback in the past - and is still sometimes done by scientists riding dirt bikes with backpacks full of fish.
Planes can drop 35 000 fish in a single flight.