But the biggest challenge for razorbacks was yet to come. By 1980, more than fifty new fish species had been introduced into the Colorado River Basin. Some arrived by accident, but many were stocked intentionally, including sport fish like bass and trout. These new arrivals turned the native fishes’ habitat into a fiercely competitive zone. Not only did the razorbacks have to compete for food and space, but the sport fish began feeding on native fish, causing populations to plummet even further.