How to Save the Critically Endangered Formosan Landlocked Salmon
Solution complète
Formosan Landlocked Salmon
Shei-Pa National Park Headquarters, National Park Service, Ministry of the Interior
The Formosan landlocked salmon (Oncorhynchus masou formosanus) is a rare species inhabiting high-altitude cold streams in Taiwan, the southernmost range of salmonids in the Northern Hemisphere. A relic of the Ice Age, its population declined drastically in the 20th century, reaching only 200 individuals by the 1990s, leading to its Critically Endangered status on the IUCN Red List.
In 1994, Shei-Pa National Park initiated a conservation program combining in-situ and ex-situ strategies, including artificial breeding and habitat restoration. Over 30 years, these efforts have boosted the population to over 10,000, reestablishing it in lost habitats.
Dernière modification 15 Jan 2025
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Contexte
Challenges addressed
- The Formosan landlocked salmon, once an integral part of indigenous cultures and a source of protein for local communities, faced severe population declines due to highland agriculture and human development. Its numbers plummeted to around 200 individuals, and its distribution range shrank by 90%.
- In 1984, it was declared a rare and precious species, and in 1989, it was officially classified as an endangered species in Taiwan. The species is also listed as Critically Endangered (CR) on the IUCN Red List.
- Due to the species' low population and the added pressure of global warming, restoration efforts must not only overcome the original technical challenges but also address issues like genetic homogenization, habitat fragmentation and degradation, and local livelihoods.
Emplacement
East Asia
Traiter
Summary of the process
Since its establishment, Shei-Pa National Park prioritized the conservation of the Formosan landlocked salmon and the restoration of its habitats. In 1994, the park set short-, medium-, and long-term goals for the salmon’s conservation. The initial step was artificial breeding of the salmon to boost the population, followed by efforts to reintroduce them into their natural habitats.
In 2000, the park held a Formosan Landlocked Salmon Conservation Symposium, where a dual strategy of ex-situ and in-situ conservation was established, divided into three phases:
- Restore the Qijiawan River basin to support a healthy, self-reproducing salmon population;
- Restore three historical river basins in the Dajia River watershed to support healthy, self-reproducing populations;
- Restore the historical salmon populations in the upper Dajia River.
Over the next four years, researchers studied the salmon's life cycle, completing the full artificial breeding process and ensuring sustainable breeding techniques. After successfully rearing the fish, they began releasing them into historically populated streams. Habitat conditions became critical, particularly the presence of excessive silt traps in the major streams. These traps were then removed to restore ecological corridors
Building Blocks
The Establishment of Shei-Pa National Park in 1992
Shei-Pa National Park has included the Qijiawan River catchment in its protected area, with conservation plans focusing on habitat preservation and breeding programs.
Enabling factors
- The Formosan landlocked salmon, discovered in 1917, is a unique species that is considered a "glacial relict." It is found exclusively in the high-altitude streams of central Taiwan, marking the southernmost and highest-altitude wild distribution of any salmon species in the world. This species is regarded as a natural monument and an iconic national treasure.
- By 1984, the Formosan landlocked salmon was nearly extinct, with 90% of its historic range across five streams reduced, leaving only about 200 individuals.
- In 1989, the Wildlife Conservation Act was enacted, listing the Formosan landlocked salmon as an endangered species (EN), signaling the urgent need for conservation.
Lesson learned
- During Taiwan's economic miracle in the 1960s to 1980s, human development spread to the mountains, leading to overfishing, water pollution, and habitat destruction. To conserve the Formosan landlocked salmon, the Wildlife Conservation Act was enacted, and Shei-Pa National Park was established to strengthen protection efforts.
Resources
Comprehensive life-cycle breeding program (Ex-Situ Conservation)
A comprehensive artificial breeding program was established over four years, producing 10,000 fish annually for conservation and reintroduction. Challenges included low genetic diversity and habitat-specific requirements.
Enabling factors
- A gene bank was established based on the concept of Noah’s Ark, aimed at increasing the population of the Formosan landlocked salmon through artificial breeding.
- In 2000, the Formosan Landlocked Salmon Conservation Symposium was held, where a comprehensive conservation framework was developed. The goal was to gradually restore the five historical streams in the upper Dajia River, where the salmon originally thrived, within 30 years. A dual strategy of in-situ (on-site) and ex-situ (off-site) conservation was adopted.
Lesson learned
- Purely artificial breeding methods can reduce genetic diversity, so it is essential to establish a complete and sustainable breeding program.
- There is limited experience in reintroducing endangered species, making it crucial to understand the life history and habitat requirements of the Formosan landlocked salmon.
Reintroducing the Salmon to Its Historical Habitats (Ex-Situ Conservation)
Following habitat restoration efforts, including the removal of silt traps and reforestation along riverbanks, the salmon were reintroduced to five historical streams. Technologies, such as mini radio transmitters, were used to track the salmon’s behavior and assess the suitability of their restored habitats.
Enabling factors
- The Formosan landlocked salmon is a keystone species in stream ecosystems, with its presence helps maintain ecological balance. Restoring populations in historically distributed areas promotes the integrity and stability of local ecosystems.
- The three-phase goal set at the 2000 Formosan Landlocked Salmon Conservation Research Symposium aims to restore its natural habitats, expand the species' natural distribution range, and reduce survival risks posed by issues like climate change.
- The 2005 Wuling Stream Long-Term Monitoring Integrated Plan (2005-2013) involved monitoring habitats and species prior to the silt trap improvement plan, laying the groundwork for the restoration of ecosystem balance.
- In 2017, a cross-regional collaboration with Taroko National Park enabled the release of Formosan landlocked salmon into Hehuan and Nanhu rivers, which are at higher elevations than the Qijiawan River.
- Releasing salmon into different streams and different sections of the same stream fosters evolutionary diversity, contributing to the genetic diversity of the Formosan landlocked salmon.
- In October 2023, a breakthrough in reintroduction techniques overcame the challenge of transporting fish over long distances. Through waterless transport, the eggs were transported and reintroduced into the upper reaches of Nanhu River, at an altitude of 2,200 meters in Zhongyangjian River.
Lesson learned
- In 2004, Typhoon Aere brought heavy rains and landslides that destroyed the hatchery along the Qijiawan River. The previous efforts were washed away, causing a 2–3-year disruption in the off-site conservation work. However, researchers and conservationists, equipped with prior experience, remained determined to persist in their efforts. To mitigate the impact of future extreme weather events, they also began releasing salmon into multiple streams, dispersing the risks associated with such climatic challenges.
Collaborating with Local and Indigenous Communities (Ex-Situ Conservation)
Indigenous Atayal communities played a vital role in conservation patrols and monitoring environmental changes. Partnerships not only created employment opportunities but also strengthened the cultural connection between the communities and the species.
Enabling factors
- In 2000, neighboring indigenous communities and partners (Sqoyaw Village and Nanshan Tribe communities) formed informal fish protection teams to protect the Formosan landlocked salmon within their traditional territories.
- After the release of the salmon, monitoring and management efforts became essential, with collaboration from indigenous communities and local neighborhoods being prioritized.
- Shei-Pa National Park's rugged terrain and vast management area make it ideal for indigenous people, who are familiar with the local landscape and can assist in comprehensive patrolling.
- Indigenous communities possess rich traditional ecological knowledge, enabling them to detect habitat changes, identify threats from invasive species, and notice abnormalities in the ecosystem, providing invaluable insights for conservation efforts.
- A co-management mechanism involving indigenous communities and local neighborhoods fosters more effective conservation actions and reduces potential conflicts, such as poaching or illegal activities.
- This collaboration also provides employment opportunities for indigenous communities, alleviating economic pressure caused by the reduction of traditional hunting or farming activities. It integrates conservation efforts into the local economy, creating a win-win situation for both conservation and social development.
Lesson learned
- The final success of conservation efforts relies not only on the introduction of professional techniques but also on local community participation and the enhancement of awareness.
Habitat Restoration (In-Situ Conservation)
Enabling factors
- The conservation initiatives launched in the 1980s ultimately faced setbacks, with efforts declared unsuccessful in the 1990s. Key challenges identified included the absence of deep pools and typhoon shelters in high-altitude streams, along with disrupted habitat connectivity caused by silt traps.
- Between 1999 and 2001, four silt traps on Gaoshan Creek, a tributary of Qijiawan River, were gradually removed or improved, leading to the observation of natural spawning by juvenile salmon.
- In 2010, an assessment revealed that the No. 1 silt trap at the lowest part of Qijiawan River was a critical bottleneck, and it was removed in 2011.
Lesson learned
- After the improvement work on the weirs, the movement of silt and sand has altered the riverbed morphology both upstream and downstream, impacting the habitat environment and water quality—critical conditions for the survival of the salmon. Continuous monitoring is essential to track the trends and characteristics of riverbed evolution.
Reforestation and Water Quality Improvements (In-Situ Conservation)
More than 500,000 native trees were planted, converting polluted farmlands into forested areas. Additionally, wastewater treatment systems were implemented to minimize runoff from recreational zones.
Enabling factors
- High-altitude agriculture in the upper Dajia River and its tributaries polluted the ecosystem, with water quality degradation being a primary factor in the near extinction of the Formosan landlocked salmon.
- An intact forest environment supports the three critical conditions for the salmon's survival: temperature regulation, food availability, and clean water.
- In 1997, plans were initiated to install wastewater treatment systems to manage sewage from Wuling Farm and surrounding recreational areas, with the first plant becoming operational in 2002.
- Negotiations with Wuling Farm facilitated its transition toward eco-tourism, reducing agricultural activities and reclaiming farmland for reforestation.
- In collaboration with the Forestry Bureau, 500,000 native trees were planted along the Qijiawan River and on reclaimed farmland to restore the riparian ecosystem.
- In December 2006, the final 8.1 hectares of private land in the Wuling area were acquired, ensuring the Qijiawan River habitat remains free from pollution caused by high-altitude agriculture.
Lesson learned
- The presence of high-altitude agriculture stems from the economic needs of indigenous and local communities, highlighting the importance of fostering dialogue aimed at co-existence and mutual prosperity.
Educational Initiatives
Programs like eco-classrooms, guided tours, and school collaborations raised awareness, while immersive experiences, such as observing salmon in their natural habitats, fostered public engagement.
Enabling factors
- The Formosan landlocked salmon serves as a vital environmental indicator; protecting this species contributes to overall environmental improvement.
- Environmental education initiatives include interpretive services and guided tours along Qijiawan River, collaborative community and tribal education efforts, conservation-focused courses and ecological camps designed with schools, and volunteer recruitment for hands-on conservation work.
- Plans are underway to introduce immersive experience classrooms, where participants can wear wetsuits and enter the stream to observe the Formosan landlocked salmon in its natural habitat. These experiences aim to deepen public understanding, foster care, and inspire action to protect stream ecosystems and water resources.
Lesson learned
- The general public lacks sufficient awareness of the Formosan landlocked salmon. Environmental education through diverse channels is essential to garner greater support for conservation efforts.
Impacts
From 1994 to 2023, the salmon population increased from 200 to over 18,000, with its habitat expanding from a single stream to five major river basins. These efforts highlight the importance of integrated conservation strategies, combining habitat restoration, aquaculture expertise, technical innovation, public engagement, and indigenous collaboration. This success demonstrates humanity's ability to resolve the environmental crises it has created.
Beneficiaries
Formosan Landlocked Salmon, local species, indigenous people and local community members, tourists, volunteers, ecosystems
Sustainable Development Goals
SDG 6 – Clean water and sanitation
SDG 11 – Sustainable cities and communities
SDG 13 – Climate action
SDG 15 – Life on land
Story
LIAO Lin-Yan, who joined the conservation team in 1999 with his expertise in aquaculture and is now the head of the Wuling Station at Shei-Pa National Park Management Office, said:
"The streams in Taiwan are steep and short, flowing from the Central Mountain Range to the Pacific Ocean in the east and to the Taiwan Strait in the west. These short distances make them highly vulnerable to environmental changes. Sudden heavy rainfall or droughts can significantly impact the Formosan landlocked salmon. When the ecosystem becomes unbalanced, the salmon population declines. Therefore, the salmon serves as a crucial environmental indicator. Protecting this indicator not only helps improve the immediate environment but also contributes to the overall ecological health of Taiwan."
