Dams altered water temperature and inundated habitats necessary for survival. Those razorbacks that do spawn in the wild are disadvantaged by carp and other non-native fishes that eat the eggs. The result is a severely depleted native stock of mostly very old fish. The oldest razorback suckers in the wild probably hatched during the Eisenhower Administration. These fish do live a long time, up to 45 years but now without successful natural reproduction.
Old fish make up most of the population, and the population gets smaller every year.
That translates to a small number of fish in a small area. Our annual round-up helps us manage for a wild population that is increasingly becoming older. This spring, biologists collected 80 razorback suckers in Lake Mojave between Willow Beach National Fish Hatchery and Hoover Dam. Those fish yielded 300,000 larvae that will be stocked throughout the Colorado River system when they are larger. Leading edge captive breeding techniques, like sperm cryopreservation and egg storage, allows biologists to ensure a diversity of genetic material for future generations of razorbacks.