 For 2008 the total population of the humpback chub in the Grand Canyon is estimated at 6000 to 10.000.This is a 50-percent increase over the estimation of 2001 and a reversal of the declining trend between 1989 and 2001.It seems that a combination of human-caused and natural events stabilized the population, particularly the experimental flooding of the canyon and the increase in water temperatures due to draught conditions over the last decade.