TAIPEI (Taiwan News) — Once vanished for decades, the Taiwan white minnow is making a comeback after targeted habitat restoration in Nantou and Taichung, CNA reported.
The shallow-water fish, also known as Pararasbora moltrechti or Moltrecht’s minnow, was first recorded at Sun Moon Lake in 1908 and later found in nearby rice paddies and streams. Its population collapsed after reservoir construction raised water levels by nearly 20 meters, destroying its habitat.
Surveys between 1995 and 2004 later identified small remnant populations in Nantou County and Taichung, but some sites disappeared again due to wastewater discharge and invasive species. Today, the fish survives only in a handful of streams and water bamboo fields in Puli Township and the upper reaches of Shishuike Creek.
Because the species is highly sensitive to environmental change, it faces ongoing threats from habitat fragmentation, agricultural water diversion, sediment control works, pollution, and competition from invasive fish. Its extremely limited distribution has made conservation urgent.
In 2022, authorities launched ecological restoration projects at sites including the Tainiu River, reshaping channels to create deep pools, shallow riffles, and low-flow areas suited to native species such as the Taiwan white minnow and Formosan dace. Community-built ecological ponds in Zhanghu Creek further expanded suitable areas.
Designed to minimize environmental disturbance, the ponds preserved natural landforms, retained existing trees, and used locally sourced stone. Water outlets were oriented downstream to support fish movement, while aquatic vegetation and minimum depths of 50 centimeters provided shelter during dry seasons.
Recent surveys show the effort is paying off, with white minnows in two restored ponds rising from fewer than 40 to nearly 170. While overall populations remain small, officials said the upward trend suggests habitat restoration can offer the species a viable path to long-term survival.
