Biologists with Colorado Parks and Wildlife have been working along Bear Creek in Colorado Springs to help save Colorado’s state fish: the greenback cutthroat trout.

On June 7, and again on Tuesday, aquatic biologists stunned the fish, netted them, and then scooped them into buckets.

According to a release, they then stripped the male fish of their ‘milt’ -- or semen, which was mixed with the ‘roe’ – or eggs of female greenback trout in a makeshift lab along the side of the creek.

According to Colorado Parks and Wildlife – in 1937 the species were considered extinct, the victims of pollution from mining, pressure from fishing, and competition from other species.

The work they’re doing, helps biologists to breed the fish in a hatchery setting to rehabilitate the population.