Decadeslong conservation efforts to save a unique Taiwan salmon species are bearing fruit.
Deep in the mountains of Taiwan’s Xueshan Range, the normally obscure Bilu Creek caught the attention of nature conservationists across the country last November. Their interest was piqued by the release of 300 one-year-old Formosan landlocked salmon by officials from Shei-Pa National Park (SPNP) in the north-central region. The move marked the park administration’s most recent effort to repopulate local waterways with batches of the endangered species bred at SPNP’s Wuling Station. “The aim of the conservation mission is to bring the fish back to each of the creeks where it once thrived,” said Station Chief Liao Lin-yan (廖林彥).
Shei-Pa National Park staffers release Formosan landlocked salmon into Bilu and Hehuan Creeks in the Xueshan Range of Taiwan’s north-central region. (Courtesy of SPNP)
First discovered in the late 1910s during the Japanese colonial era (1895-1945), the endemic species was once a common sight in streams feeding into the upper section of the Dajia River, which meanders through central Taiwan before emptying into the Taiwan Strait. When SPNP was established in 1992, the salmon population had dwindled to some 200 for reasons ranging from agricultural development to fishing activity. By that time the fish could only be spotted in two Dajia tributaries, Qijiawan and Gaoshan Creeks, both of which run through the Wuling area where the station is located.
The results of releasing captive-bred salmon into the two creeks in the first years of SPNP’s establishment were less than encouraging. When Liao started working at Wuling Station in 1999, the population had inched up to just over 400. But the situation has improved at a faster pace since, with the number reaching an unprecedented 12,587 in 2020.
A major component of the conservation work is removing sand-blocking weirs. Between 1999 and 2001 Wuling Station partially tore down four barriers in Gaoshan followed by another in Qijiawan in 2011, allowing the salmon to travel along the waterways more freely to mate with fish previously separated by the low dams. The endeavor is expected to improve the genetic diversity of the species and thus help it withstand challenges posed by environmental stresses.
As Formosan landlocked salmon can reach up to four years of age, Liao spent four years intensively researching the species to develop a comprehensive understanding of its life cycle. The information gleaned during his studies is used to create favorable conditions for the fish at Wuling Station’s hatchery. The facility keeps over 10,000 salmon, mostly fingerlings ready to be released.
Positive Results
According to Liao, the station initially focused on replenishing salmon populations in Qijiawan and Gaoshan to build a solid foundation for its conservation project. In the mid-2000s it began shifting its attention to other streams that were once home to the species. “It’s important to bring the fish back to these satellite rivers. Once it’s seriously affected in a certain creek, the species still can survive in other places,” he explained.
SPNP’s Wuling Station near Qijiawan Creek is devoted to ensuring the species’ survival. (Courtesy of SPNP)
Every year the station organizes several small-scale release activities in addition to a major undertaking such as the one in May 2021 that placed 1,600 baby salmon in Nanhu Creek. Thanks to such dedicated conservation efforts, the fish can now be seen in a total of seven streams. Qijiawan Creek remains the top habitat, with more than 6,700 salmon spotted there in 2020.
Relocating salmon can be a challenging task as workers must trek deep into the mountains on foot. The trip from Wuling Station to the release locations in Nanhu Creek last year took approximately eight hours, according to Liao, who led the team carrying out the mission. “Helicopters or drones are used abroad to release fish into wide rivers in relatively flat terrain. This tactic doesn’t work in Taiwan because our salmon’s natural habitat is narrow creeks in deep ravines,” he said.
Monitoring changes in the fish population is tricky for the same reason. The annual count takes place from May through September and heavily depends on volunteers mobilized by the station. “We definitely underestimate the numbers because there are many sections of river that can’t be accessed by people. But the upward trend is unmistakable, as the sampling areas have remained the same over the past 20 years,” said Liao, amid preparations to return to Nanhu Creek to check on the fish released there last year.
Strengthened Habitat
As SPNP strives to replenish streams, the Forestry Bureau (FB) under the Ministry of Agriculture is helping create a more favorable environment for the salmon. In 1995 the FB launched a campaign to designate major wildlife habitats around Taiwan. Wuling was one of first such protected areas, and the local government announced a landlocked salmon wildlife reserve there two years later. Along with the Wildlife Conservation Act—which made harming the species a punishable offense when it took effect in 1989—the establishment of a wildlife sanctuary ensures the enforcement of stringent safeguards critical to the fish’s survival.
Tse-Xin Organic Agriculture Foundation staffers utilize self-watering planters to greatly improve reforestation outcomes in the Wuling area. (Courtesy of Tse-Xin Organic Agriculture Foundation)
The bureau’s Dongshih Forest District Office is also leading efforts to restore woodland surrounding waterways vital to the fish. Reforestation is crucial because the salmon mainly feed on larvae and aquatic insects, the numbers of which are proportional to forest canopy density. “Shade provided by trees additionally cools the water. This is critical in summer as the species declines at temperatures greater than 17 degrees Celsius,” said Wu Chen-chun (吳貞純), secretary of the Dongshih office. Forests also help retain soil that would otherwise get swept into creeks during heavy rainfall and impact the fish’s habitat.
The reforestation movement received a boost from the private sector last year, when Taipei City-based Tse-Xin Organic Agriculture Foundation and Hotai Motor Co. started cooperating with the FB to plant 13,000 trees in 11 hectares of abandoned farmland at Wuling. The government provided saplings and related know-how, Hotai offered financial support and the foundation coordinated personnel to plant and tend the trees. Tse-Xin has cultivated various strategies to improve the success rate of reforestation, most notably a patented self-watering planter co-developed by the foundation and a local social enterprise. “The devices allow trees to flourish without much care, even in places prone to water shortage,” said Cheng Li-yi (程禮怡), director of the organization’s tree-planting department. She emphasized the need to grow a diverse range of native tree species. “The species must be native so they’re resistant to diseases and diverse so that if one species gets sick, all the trees won’t be affected,” she explained.
With fish-release projects bringing the salmon to more satellite streams and the reforestation campaign improving habitat conditions, things are looking up for the Formosan landlocked salmon. Liao is cautious in his optimism, however, due to an increase in the intensity and frequency of extreme weather events in recent years. “I’ve seen typhoons bring torrential rains and carry the fish away from their habitats. A long spell of dry weather like the monthslong drought last year is equally damaging to the fish,” he said. “Taiwan has come a long way in salmon conservation, but we must remain vigilant to ensure the species’ well-being in the face of future challenges.”
Reforestation bolsters the salmon’s chances of survival as the species prefers temperatures below 17 degrees Celsius and trees provide water-cooling shade. (Courtesy of SPNP)
Write to Oscar Chung at mhchung@mofa.gov.tw