Pollution Disrupts Trout Mating Cycle

Pictures of indigenous trout abnormally mating due to environmental contamination have been released to the public.

A documentary team from Daegu Science College headed by Professor Oh Han-taek released the pictures to public yesterday in which small female trout whose growth have stopped due to a blockage of their pathway to the sea were mating with male trout in a valley. This is an abnormal type of mating for this species.

In regard to this, Dr. Lee Wan-ok, belonging to the Inland Fisheries Ecological Research Institute, an affiliated organization of National Fisheries Research and Development Institute, said, “This is an abnormal type of mating and a type of incest. Because of this, the population of trout is dwindling and the fish is becoming an inferior species.”

The documentary team, meanwhile, succeeded in photographing trout mating at a Beopsuchi valley (Yangyang-gun, Gangwon Province) on October 2. They have only resided in this valley because of environmental contamination that has blocked them from going to other places.

In September 2004, this team released pictures of normal trout mating to the public in which normal female trout, whose sizes were bigger than the males, returning from the sea were mating with several small male trout in Okryudong valley in Mt. Geumgang (North Korea).

Jin-Kyun Kil leon@donga.com