Although an additional energy cost would be incurred by maintaining a photoperiod and temperature regime different from the natural environment, the economic benefit from an efficient use of hatchery resources should outweigh the cost. Using a Constant Spring photoperiod and temperature, males and females containing large numbers of mature gametes can be maintained over eighteen months. Using an Advanced six month annual photoperiod and temperature cycle, both males and females can go through a complete reproductive cycle, from spent to mature, in three months less time than occurs in the wild. The coupling of the two different photoperiod and temperature regimes, Constant Spring and Advanced, may increase the spawning potential of each individual urchin to several times per year, reducing potential size, therefore cost, of a broodstock maintenance system. Year round hatchery production, not just out-of-season, may be a better economic solution for green sea urchin aquaculture.