Every ball that srikes the green makes some sort of indentation or pitch mark on the green. The mark needs to be immediately repaired (by the person whose ball made it, or perhaps by YOU following behind that golfer). Fixed within 24 hours of being made, the damage will be completely healed within a day or two. Left unrepaired for more than 24 hours, and the damage will take several weeks to heal.
As the Men's Golf group on the island, LMGA members should lead the way in encouraging your playing partners, and all your friends, to repair their marks, and some extra ones left by others.
However, there's a right way and a wrong way to do this - a lot of folks think they should use the tool like a lever to lift the soil and grass back up to fill the void, but that method does more harm than good. The proper way is to take the grass at the back edge of the mark, that has been pushed away in the direction of the ball flight, and use the tool to stand the grass back up by inserting the tool and leaning it towards the center of the mark that the ball took in making the mark.
The following video is worth watching! If every golfer would fix his own marks, and a few others that he encounters while playing, our greens would be in much better shape.