 The Catholic priests forbade the Indians from practicing their native culture, resulting in the disruption of many tribes' linguistic, spiritual and cultural practices.With no acquired immunity to the new European diseases and changed cultural and lifestyle demands, the population of Native American Mission Indians suffered high mortality and dramatic decreases especially in the coastal regions where population was reduced by 90 percent between 1769 and 1848.When Mexico gained its independence in 1834, it assumed control of the Californian missions from the Franciscans, but abuse persisted.