Most marine fish, including reef fish, spawn by "broadcasting" their eggs into the water. The act of spawning is essential to the preservation of any reef fish population. That is why some spawning adults should be protected permanently from removal within their specific spawning places. If animals of any kind, including reef fishes, are to continue into the future, they must produce enough young to survive to maturity and reproduce similar numbers of offspring. Broadcast spawning is a relatively inefficient way to ensure fertilization and subsequent development of eggs and newly-hatched larvae, that are unprotected as they grow in ocean waters. To be successful, many millions of eggs and sperm need to be released so that relatively few can escape predation before reaching maturity and their own spawning. Larger females produce more eggs, so protecting large, old females is particularly important.  Most spawning locations are known to fishermen and have historically been targeted especially during reef fish aggregations for spawning. The concentrated harvest of large adult fishes greatly reduces the potential future egg supply, and in time a great reduction in the regional supply of eggs, juveniles and future adult fish. Overharvest of fish caught now comes at the cost of much smaller numbers of fish available for harvest in the future. Larger females produce more eggs, so protecting large, old females is particularly important.