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The Formosan landlocked masu salmon is in the way to recovery.

By Igor I. Solar
Posted Feb 24, 2010 in Science
The Formosan land-locked salmon (Oncorhynchus masou formosanus) is a sub-species of masu salmon endemic of Taiwan. It is believed that this variety of masu salmon became landlocked in streams of this sub-tropical island as a result of a complex process of glaciation, uplifting of a mountain range, de-glaciation and evolution from anadromous ancestors to a landlocked population (Lin et al, 2006). Because of this remarkable set of circumstances, the Formosan salmon is one of the southernmost wild populations of salmon in the world, a real miracle of fish biodiversity and a biological treasure for Taiwanese people.
The adult fish is small, about 12 inches, and inhabits cold, slow-flowing streams at elevations above 1,500 m. such as the Tachia and Chichiawan rivers. It requires warmer water than most salmonids ranging from 5 to 16°C.
Formerly part of the regular diet of the aboriginal Taiwanese people, it was identified as a masu salmon subspecies in 1919. Historical declines were caused by over-fishing, but lately, mostly by pollution. When in 1989 the population was estimated at about 200 individuals they were declared as critically endangered.
Systematic conservation efforts started in 1999 with the establishment of the Chichiawan Creek Restoration Project. This ambitious engineering and biological undertaking involved construction of several structures including pools, modifications to the creek banks and a hatchery. Another facility, the Wuling Formosan Landlocked Salmon Conservation Center, has recently recorded evidence of recovery of the nearly extinct salmonid. Current population number has increased to about 3000 individuals.
Reference: Lin, JY, Chen YC, Tsao HS, Yang HC (2006) Restoration of Formosan landlocked salmon habitat as refuge during high flows, J. of Japanese Society of Civil Engineering, (Doboku Gakkai Ronbunshuu D.) 62 (4): 320-329. (Available at: .