A group of ancient species that occupy a unique ecological niche, taimen are the largest salmonids in the world. Taimen can live over 30 years and reach 6 feet in length and over 100 pounds in weight. Due to their voracious appetite and their place at the top of the food chain (some feed on ducklings and adult Pacific salmon), taimen are sometimes called “river wolves” or “river tigers”. Check out the trailer to our new film “River Tigers” premiering at Banff Film Festival November 2020.
These species represent an important evolutionary legacy in the global family of salmon and trout. Taimen also serve as a bellwether for ecological change. Because taimen reach maturity later and live longer than other salmonids, they are more sensitive to changes in their environment and serve as an important indicator of the health of the great rivers of Asia and Europe.
Taimen face an uncertain future in their native habitat, which spans the Japanese Island of Hokkaido, Russia’s Sakhalin and Kuril Islands and far eastern mainland Russia, Mongolia, China, and the Korean peninsula. The International Union for Conservation of Nature (IUCN) consider taimen species status to range from vulnerable to critically endangered. However, because they are not a commercially harvested species, taimen have been poorly studied until recently.
Unfortunately, taimen are in decline across much of their range due to habitat loss and unsustainable fishing pressure. As large fishing targets, harvest of taimen is a big cause of decline. They reproduce slowly, waiting until late in life. As an apex predator, they also rely on healthy prey populations and impacts to the prey base will also impact taimen.
An important milestone was reached in 2012 with the completion of range-wide status assessment of all the species in the genera Hucho and Parahucho. These species were added to the IUCN Red List of Threatened Species, and the assessors concluded all taimen species were either Threatened or Data Deficient, underscoring the need to take immediate action to reverse declining trends observed throughout their range.
- Danube salmon Hucho hucho, Endangered
- Sakhalin taimen Parahucho perryi, Critically Endangered
- Siberian taimen Hucho taimen, Vulnerable
- Sichuan taimen Hucho bleekeri, Critically Endangered
- Korean taimen Hucho ishikawae, Data Deficient
WSC’s on-going work has focused on two species, Sakhalin and Siberian taimen (learn about each species below). In addition, we have established a strong, international network of specialists dedicated to work on the other taimen species. To fill in the gaps in our understanding of these enigmatic species with the hopes of furthering their long-term survival, WSC is working with the IUCN Salmonid Specialist Group and partners in Japan, and the Russian Far East. These research efforts are focused on three separate areas:
- Understanding extinction risk and describing ecological and genetic differences among a group of key river populations within their natural range;
- Describing migration, life history patterns, and foodwebs;
- Carrying out river expeditions to identify key habitats (particularly spawning habitat) and developing methods to estimate adult population abundance to provide a baseline for our conservation work.
Armed with emerging knowledge from our field and laboratory research efforts, WSC is leading efforts to conserve critical habitat for taimen. We have also worked on educational initiatives, strengthening local watershed councils, and encouraging sustainable fishing practices to further advance taimen conservation.
Through community involvement, education and science-based strategies to identify and protect taimen strongholds, we have an important opportunity to protect this critically endangered, flagship species, and to make a lasting contribution to the health of Asia’s remarkable wild salmon ecosystems.
Siberian taimen (Hucho taimen) have the broadest distribution of all taimen, and are recognized as the largest member in the group. Their range extends from the Ural Mountains in Europe to the Amur River in the Russian Far East, an area representing approximately one-tenth of the land area of the Earth. Despite this huge range, the species was assessed as Vulnerable by IUCN in 2012 based on evidence of a long-term decline in abundance, primarily a result of overfishing and illegal fishing practices.
In Khabarovsk, Russia, we’ve been conducting field studies to better understand the feeding patterns of taimen, which grow to enormous size by consuming adult salmon. Local Siberian taimen in Khabarovsk are the only populations that feed on returning adult Pacific salmon.
We have also been working closely with our Russian partners to establish protected areas for this species in Khabarovsk, in the lower Amur River region.
Wild Salmon Center and our partners at Khabarovsk Wildlife Foundation are this year working on new protections in the region that would create a network of adjacent reserves totaling 3.5 million acres—50 percent larger than Yellowstone National Park. Following the establishment of the 200,000-acre Tugursky Nature Reserve in 2014 and the 70,000-acre Nimelen Reserve in 2018, a new 1 million-acre expansion is scheduled on the Tugur and another new reserve on the Maya River, a remote and wild tributary of the Uda (see map).
Wild Salmon Center has also begun a new science project with Mongolia River Outfitters to conduct a first-of-its-kind taimen research project in that country on the Onon and Delger rivers, including spawning studies in spring, and summertime monitoring programs to track taimen abundance, feeding behavior, and river temperatures.
This research aims to understand how taimen spawn, feed, and grow in rivers—both with, and without, the marine nutrients provided by salmon.
We look forward to combining forces to develop a more integrated, international effort to conserve these river giants.
Initially grouped with all other taimen (Hucho), genetic studies have shown that Sakhalin taimen should be placed in their own genus (Parahucho). They are thought to be the only species of taimen that spends part of its life history in the ocean.
WSC helped carry out ten years worth of research to conserve Sakhalin taimen (Parahucho perryi) including a two year study on Japan’s Sarufutsu River. An important component of our research efforts was highlighted in a scientific paper describing Sakhalin taimen extinction risk. The paper details environmental factors that shape their distribution and identifies key watershed characteristics that support stable taimen populations. The study concluded that the species prefers intermediate levels of precipitation, cold temperatures, and minimally developed agricultural land. In addition, the authors identified the crucial role that river floodplains play in conserving this species, especially large lagoons.
A range-wide status assessment for the species was completed in 2006 and concluded the species was Critically Endangered. Since that time we have maintained an active research program on these fish to help guide our conservation work (see our publication on the species extinction risk here).
As part of conservation recommendations highlighted in the IUCN assessment, Wild Salmon Center has made progress on protecting key river habitat.
The Koppi River in Khabarovsk is a Sakhalin taimen stronghold. With our partners at Khabarovsk Wildlife Foundation, we are working on base levels of protection from headwaters to sea on the most biodiverse salmon ecosystem in the world—featuring Amur tigers, Blakiston’s fish owls, Steller’s sea eagles, and as well as Russia’s strongest remaining runs of Sakhalin taimen and Asian masu salmon (also known as cherry salmon).
We are also expanding protections elsewhere:
- Vostochny Refuge, Sakhalin, Russia
- Dagi and Nabil Rivers, Sakhalin, Russia
- Sarufutsu Environmental Conservation Forest, Hokkaido, Japan
These protected areas, amounting to more than 1,000 square kilometers (an area larger than the size of the Shenandoah National Park in the eastern United States), helps us secure the future of this threatened species. Sensitive riparian and floodplain habitat, increasingly under development threat, is now under permanent protection.