The effects of hydrogen peroxide, cold storage and decapsulation on diapause in parthenogenetic Artemia cysts from the Izmir Camalti saltern were tested. To test the effect of hydrogen peroxide, cyst samples were incubated for 5 min in a 2% or 5% H2O2 solution. In the cold storage experiments, the cysts were divided into three groups. One group was stored in saturated saline, the second in a vacuum and the third in air for 15 days or one month. Decapsulation was tested after a 2-hour prehydration period. The hatching rate of the control group after 24 h in cysts harvested in November was 0, while in cysts harvested in March it was 19.2%. All the treatments for diapause deactivation resulted in increased hatching during the first 24 h but the final hatching rates (at 72 h) of all treated groups were similar to or slightly lower than that of the control.