I have done a lot of spearing over the years and believe me if the marlin just sits there and waits to be speared after it is teased up it is the only fish in the world that does.I have also line fished for marlin and probably 10% of those released dont see the next sunset.At the end of the day its not spearos depleting the stocks or the sport fisherman-but the long liners etc are another story.
Happy spearing
greg