A recovery plan was prepared in 1988 with implementation began later the same year.
Intensive control of predators (Rattus rattus) reduced adult mortality from 24% to 9% with nesting success increasing from 15% to 63% (Robertson et al., 1994). By 2000, the populations had reached 221 individuals and in 2001-2003, 30 young birds were transferred to rat free island of Atiu (200 Km northeast of Rarotonga) in an apparently successful attempt to establish second insurance populations. In 1904, a shipment of nursery stock from China brought a fungal blight to United States.
Within 40 years, American chestnut had disappeared from its native range. Efforts are now underway to transfer blight resistant genes into few remaining American chestnuts that weren’t affected by the fungus or to find biological controls for fungus. Whirling disease caused by Myxobolus cerebralis is decimating trout populations in many western states. The parasite is believed to reach into United Slates in 1956 in a shipment of frozen fish.