Saving the Japanese giant salamander from concrete

Saving the Japanese giant salamander from concrete

The Japanese giant salamander has been declared vulnerable to extinction by the IUCN. As river concrete endangers its survival, a group of conservationists is fighting to repair the damage.

Reading time: 41 min.

Cover image: A Japanese giant salamander in a river in Japan © TopOutImages/Yukihiro Fukuda

It’s night-time and we’re walking up a narrow river, knee-deep in water. Every step is precarious on the uneven riverbed visible under the gaze of our torches, but the sense of adventure and freshness rising from the flowing water make our journey into darkness unexpectedly pleasant.

After 100 metres, we reach a concrete wall taller than any of us. Water gushes down over the wall’s lip forming a white curtain that hides the concrete behind it. Looking down at the hard floor, we find what we’ve been looking for. A creature maybe 70 centimetres long, brown and speckled like a river stone. A Japanese giant salamander.

It moves incessantly, its head, engulfed by the white curtain that smashes against it, pushes against the wall. Visible are its body and tail wiggling frantically, but the concrete doesn’t budge. We watch the creature fight with all its might as it moves along but not over the barrier.

On the side of the river, outside the curtain of water, the salamander curls up and lies still. It’s hard to say what an amphibian who looks like it has time-travelled from prehistoric times is thinking, but in human terms, it looks exhausted. Resigned even. There’s a wall and it can’t move upstream. It’s simple physics.


Back on the dry asphalt, enveloped by the sound of cicadas, we fall silent. Seeing a Japanese giant salamander for the first time was as invigorating as the clear night sky. But it was also disheartening to see this creature whose ancestors roamed the Earth long before our own struggle against something as ordinary as a concrete wall.

The scene keeps playing in our heads as we return home, each wrapped in our thoughts.

That night, under the watchful gaze of our guide Richard Pearce, we saw firsthand how small dams or “weirs” usually no more than two metres tall stop Japanese giant salamanders (Andrias japonicus) from moving freely along rivers and streams. These creatures aren’t meant to crawl up concrete barriers, which fragment their habitat and prevent them from moving upstream to reach less disturbed areas, forcing them to live downstream in more limited spaces. River infrastructure also destroys the natural holes or dens that these nocturnal animals hide in during the day and that are key to their survival because this is where they breed and nest their eggs. “In their natural condition, salamanders are good at camouflage, but they’re actually very conspicuous on a shallow concrete surface,” says Pearce, describing how out-of-place the Japanese giant salamander we saw that night looked.

At stake is the ability of Japanese giant salamanders (JGS) to survive in the rivers of central and western Japan, their only habitat on Earth. In late 2021, Pearce founded the NGO Sustainable Daisen to spearhead conservation of this amphibian in the Nawa River basin in Daisen, a rural town of 15,000 inhabitants that looks out onto the Sea of Japan and is located in the western prefecture of Tottori. One of Sustainable Daisen’s main goals is to build ramps across weirs to allow salamanders to migrate freely along rivers once again. By building ramps, Pearce hopes to rarely see the animals once their access to more pristine habitats has been restored. “I’m in ecotourism and I’m basically trying to put myself out of work,” he says, without a trace of humour.

A male Japanese giant salamander protecting his eggs inside a den. Yukihiro Fukuda, a 2014 Wildlife Photographer of the Year finalist, spent six years capturing this salamander, named Fukuda-kun in the photographer’s honour, before taking this rare shot © TopOutImages/Yukihiro Fukuda
Japanese giant salamander_C_TopOutImages Yukihiro Fukuda
Japanese giant salamanders are nocturnal animals and they hide in naturally formed holed or burrows during the day. “In their natural condition, (they’re) good at camouflage,” says conservationist Richard Pearce © TopOutImages/Yukihiro Fukuda

Pearce runs ecotours for people to see and learn about Japanese giant salamanders in the Nawa River basin, which lies at the foot of Mount Daisen, a dormant volcano and Tottori’s highest peak (daisen means “big mountain” in Japanese): like us, many have followed his towering figure wading through Tottori’s rivers. Originally from the UK, Pearce moved to Japan in 2010, combining studies in environmental management and a passion for travel to become an ecotourism consultant — though he says he “doesn’t like labels” — as well as designing adventure tours and owning a guesthouse in Daisen. In 2017, Pearce was asked by the Japanese Environment Ministry to design a JGS tour in another part of Tottori, the Hino River of Nichinan town, which he describes as a successful venture before the pandemic shut it down. Up to thirty participants, invariably foreigners (mostly from the United States, Europe and Australia), flocked to this remote corner of Japan every year to visit one of the most renowned Japanese giant salamander habitats on the planet accompanied by a leading authority on this animal, Sumio Okada, director of the Hanzaki Research Institute (hanzaki is one of two names for JGS in Japan, the other is ōsanshōuo).

Mount Daisen (1,729 metres) is a dormant volcano and the highest peak in Japan’s Tottori prefecture. The mountain was once considered sacred and, for this reason, its beech forest, one of the largest in western Japan, has been left intact © Sustainable Daisen

The Japanese giant salamander, a “living dinosaur” whose biology has changed little over the past 23 million years, is a bucket-list animal for many amphibian enthusiasts. It’s one of only three main giant salamander species on Earth and is known to grow up to 1.5 metres in length and 44 kilograms, making it the second largest salamander after its Asian cousin, the Chinese giant salamander (Andrias davidianus) and followed by the hellbender (Cryptobranchus alleganiensis), endemic to the US. The JGS has found its perfect habitat in rivers between 100 and 1,000 metres in altitude where the water is cool and oxygen, which salamanders absorb through their skin, abundant. 

While the salamanders’ biography spans geological epochs, its story is being rewritten by very modern pressures. Even though JGS populations are woefully under-researched not only in Daisen but in many other parts of Japan, experts have enough evidence to believe this animal is inching closer to extinction. In December last year, the International Union for Conservation of Nature (IUCN), which compiles the Red List of Threatened Species, updated the Japanese giant salamander’s conservation status from “near threatened” to “vulnerable”. This puts the JGS in a “threatened” Red List category and in line with a disturbing global trend: 41% of over 8,400 identified amphibian species are classified as being threatened with extinction by the IUCN, making this the most at-risk class of vertebrates on the planet, with habitat loss as the primary driver behind this unhappy record.

Data: IUCN. The figures reflect increased assessment efforts by the IUCN, rather than trends in the status of biodiversity.

Habitat degradation is also the main culprit behind the JGS’ decline: concrete infrastructure in the form of dams, weirs, embankments and artificial riverbeds is a common feature in rivers throughout Japan. This can be traced back to the country’s economic “miracle” that started in the 1950s and came to an abrupt end in the 1990s, which was defined by a construction boom that sought to make Japan’s mountainous and densely forested landscape hospitable for an increasingly affluent population. Author Gavan McCormack coined the term “construction state” from a Japanese expression to describe “the centrality of construction to the Japanese political economy” — a system that has outlived the boom era and caused the homes of Japanese giant salamanders and countless other species to be invaded by concrete.

Infographic by LifeGate. Illustration by Rachel Rasfeld of Sustainable Daisen

In 2019, construction of a forest road started in Nichinan which risked endangering salamander habitats in the Hino River. At this juncture, Pearce saw his role shift from ecotourism consultant to conservation activist. “When I heard about the road being built in arguably the most well-studied Japanese giant salamander habitat in the world, I thought: they’re doomed.” Pearce and others brought their concerns to the local government and the project was temporarily suspended — though not stopped.

Pearce has since shifted his focus 40 kilometres northeast of Nichinan, to the Nawa River basin. Here, six kilometres of rivers fed by snowmelt and rain, where water is always abundant and never exceeds 25 degrees Celsius, are sandwiched between Mount Daisen and the coast, creating a unique habitat for Japanese giant salamanders as these creatures are rarely found at such low altitudes and so close to the sea. Yet the Nawa River and its tributaries are lined with dozens of weirs built primarily to irrigate fields, with as many as 15 in a one-kilometre stretch, and JGS often get stuck beneath them. After heavy rain, which washes the creatures downstream, Pearce has seen up to eleven salamanders in this predicament at a time.

Free-flowing rivers are an ideal habitat for Japanese giant salamanders © Sustainable Daisen

Together, Richard and his wife Kazumi Pearce are trying to bring the little-known issue of Japanese giant salamander decline to people’s attention. “There aren’t so many other voices of people trying to protect them,” says Kazumi.

On his part, Richard Pearce views their mission as flowing naturally from a commitment to environmental stewardship. “I’m not a Japanese giant salamander nerd, or anything like that. I love nature and animals and believe we can do something to save them,” he says. “Twenty-three million years of DNA might die out on our watch: I honestly believe that if we don’t do anything in time, no one else will.”

Richard and Kazumi Pearce
Kazumi Pearce (left) and Richard Pearce (right) of Sustainable Daisen, a Japanese giant salamander conservation NGO © Mara Budgen

Why Japanese giant salamanders are special

Japanese giant salamanders can live to over 80, survive without food for weeks and even regrow lost skin and bones. The peak of their activity is during the breeding season between August and October, when they migrate upstream and the most dominant male in a territory occupies and defends a burrow, becoming the “den master.” Females enter the den to fertilise their eggs, of which they can lay from 300 to 1,000 at a time. Afterwards, it’s the male who defends the eggs until they hatch one or two months later and, once hatched, the larvae stay in the nest with their father for several more months.

Scientific name Andrias japonicus
Taxonomy Amphibia (class), Caudata (order), Cryptobranchidae (family), Andrias (genus)
Habitat Rivers of western and central Honshu, Shikoku and Kyushu (Japan)
Diet Carnivorous: fish, insects, frogs, crustaceans, small mammals
Size Max recorded 150.5 cm long / 44.3 kg
Longevity Max recorded over 80 years
IUCN Red List status Near threatened (updated in 2022)

“When I was a child, I would go fishing in the river at night and see many giant salamanders,” recalls Seiji Matsuda, a rice farmer and representative of Kyunawa village, part of Daisen town. “My family didn’t eat ōsanshōuo, but others did.” Eating giant salamanders, in fact, wasn’t unusual in Japan in the mid-20th century. Salamanders’ front limbs have four digits and “according to a local belief, if you ate a salamander with five fingers, it had medicinal properties,” Matsuda adds with a chuckle. These days, you’ll be hard pressed to find a plate of giant salamanders in Japan. Hunting the species, and even touching it for those without a special licence, was banned in 1952 when the animal became a Special Natural Monument, a designation that protects national cultural assets. What you can find, instead, are JGS-themed potato croquettes and other snacks in places like Yubara Onsen, a hot spring area in Okayama prefecture, which neighbours Tottori to the south. 

Hanzaki was once the standard Japanese name for Japanese giant salamanders and alludes to their capacity to regenerate body parts as it was believed that a salamander could survive even if cut (saku) in half (han). Ōsanshōuo is the more common term used nowadays and, literally translated, means “big pepper fish”: when stressed, JGS release a sticky, white mucus that smells like Japanese peppers (sanshō).

Salamander-themed foods and souvenirs are common in areas where JGS are a tourist attraction. Nichinan’s mascot, for example, is a salamander grandpa: half-amphibian, half-old man, Ossan Shouo is a cane-wielding biped JGS with a curious green moustache, sunglasses and a gold ring. And underpinning such humorous modern-day representations are deep local histories. In Yubara, a four-century-old shinto shrine elevates the JGS to divine status. According to local legend, the shrine was built to assuage the anger of a very giant salamander who, after being killed by a villager, put a curse on its attacker and the entire village. To this day, Yubara holds a yearly summertime festival dedicated to the salamander-god.

As the chief priest of Hiyoshi Shrine in Daisen, Hiroyuki Sumi has a profound understanding of the divinity of nature in Japan’s indigenous Shinto religion. Like Matsuda, he too has childhood memories of seeing salamanders in the river before the weirs were built and remembers how his parents and grandparents would pray facing Mount Daisen every morning. “We’re alive thanks to Daisen’s riches. The mountain, especially its water, represent life; Daisen is a god.” The fact that there are fewer Japanese giant salamanders is a sign that the entire ecosystem is suffering, Sumi points out, not just its resident giant amphibians.

Seiji Matsuda is a rice farmer born and bred in Daisen
Seiji Matsuda is a rice farmer born and bred in Daisen © Mara Budgen
Hiroyuki Sumi is the chief priest of Hiyoshi Shrine
Hiroyuki Sumi is the chief priest of Hiyoshi Shrine in Daisen © Sustainable Daisen

Are they endangered?

Mizuki Takahashi’s book about animal extinction aimed at teenagers was published earlier this year in his native Japan, a country where environmental education isn’t widely taught, he says. Takahashi, an expert in amphibian ecology and conservation who studies species such as the hellbender and Japanese giant salamander, moved to the US in his late twenties and currently works as an associate professor in Biology at Bucknell University in Lewisburg, Pennsylvania. In Japan, there’s little funding for research in ecology, and “the government doesn’t provide enough jobs for ecologists … that’s one of the reasons I came to the US,” Takahashi says.

As a bilingual specialist with international experience, Takahashi is well-positioned to act as a bridge between Japanese and global experts. He was part of the assessment team that recommended the IUCN change the JGS’ Red List status to vulnerable, a category reserved for species “considered to be facing a high risk of extinction in the wild,” according to its definition. In Takahashi’s view, this is “a more accurate assessment of what’s going on,” compared to the previous near threatened classification, defined as “close to qualifying for or … likely to qualify for a threatened category in the near future.”

Mizuki Takahashi has conducted groundbreaking research on Japanese giant salamander behaviour in collaboration with Japan-based researchers like Sumio Okada. He also created a yearly summer programme to bring Bucknell University students to Japan to study the effects of habitat fragmentation on giant salamanders.


His book, published in Japan by Iwanami Shoten, Publishers is called “Is mass extinction going to happen again?”

Yet no one knows how many Japanese giant salamanders survive in the wild. “The IUCN asked for quantitative data showing the species’ decline throughout the distribution range. We don’t have that,” Takahashi explains. “But we have enough qualitative evidence suggesting they’re in a bad situation,” ​​including recent studies showing the decline of local populations and issues connected to habitat fragmentation and concrete banking in rivers. Takahashi points out that prior to the recent update of the JGS’ IUCN status, it was already classified as vulnerable by the Japanese Environment Ministry’s own Red Data Book of threatened species. Also, the international level of concern is high because over half of caudata (salamander and newt) species are under threat and all giant salamander species are declining, if not already endangered.

Chinese giant salamander at Prague Zoo
A Chinese giant salamander in captivity © Petr Hamerník/Wikimedia Commons

Unlike the JGS, “there aren’t many populations of Chinese giant salamanders left in the wild,” and the trigger points behind this decline are different compared to Japan, explains Becky Shu Chen, who is part of a team from the Zoological Society of London (ZSL) active in the conservation of Chinese giant salamanders, which are classified as “critically endangered” on the IUCN’s Red List — the most severe of the threatened categories. “(However), the ZSL folks provided a sense of urgency because not only are we losing the Chinese giant, but the Japanese one isn’t doing well either,” says Takahashi.

In fact, Japanese giant salamanders could die out. This is according to Yuki Taguchi, a member of the Japanese Giant Salamander Society, which facilitates information exchange between researchers and conservationists. There are still healthy JGS populations in places such as Asago town in Hyogo prefecture, which borders Tottori to the east, where the Hanzaki Institute is located. Here, there aren’t many weirs and salamanders are being monitored closely, for example through tracking devices known as PIT tags. However, many populations in Japan aren’t being surveyed at all and “there are probably places where local populations are already extinct,” Taguchi says. In many areas under study, Takahashi also points out that it’s difficult to find larvae and juveniles. “One female can lay up to hundreds of eggs at a time and there should be more young individuals than adults, so this indicates that either we don’t know where they are because we don’t have enough people to study the species, or that they’re not reproducing, or that larvae and juveniles aren’t surviving to adulthood.”

Yuki Taguchi is an expert in captive breeding of Japanese giant salamanders and conservation ecologists and zookeepers from all over the world visit Hiroshima City Asa Zoological Park, where he works, to learn the technique from him.


“One reason for conducting captive breeding is that it could be important in the future if the number of giant salamanders in the wild continues shrinking,” Taguchi explains.

The impact of river concrete

Naturally meandering rivers and streams near rice paddies are an ideal habitat for Japanese giant salamanders because the paddies attract animals, such as frogs and insects, that salamanders eat. A symbiotic relationship between humans and JGS was common in Japan prior to the widespread adoption of agro-chemicals and river modification. Today, this is mostly a distant memory.

“I remember when the weirs were built in the years after the war,” Matsuda, who has lived in Daisen his whole life, recalls. “The rice fields used to be irregular and the roads narrow, so farmers only used small machinery. But the government wanted to modernise agriculture and increase production by standardising the size and shape of fields and making them accessible to bigger machinery.” To do this, river courses were straightened and embankments, concrete riverbeds and weirs were built to irrigate the fields by simultaneously speeding up and controlling the water flow. The push to increase yields also led farmers to use more pesticides. “Everything changed from that point onwards, it became a vicious cycle,” Matsuda says, grimly.

A Japanese giant salamander juvenile © TopOutImages/Yukihiro Fukuda
A juvenile Japanese giant salamander © TopOutImages/Yukihiro Fukuda

Based on information shared by local farmers and fishers, Pearce is worried that poultry and pork farms upstream from a sensitive salamander habitat in Daisen are releasing waste into the river system, but because “there’s no proof of this,” he wants to start testing the water. Shinji Otani, an associate professor of Dryland Health & Medicine at Tottori University, who grew up in Daisen, is advising him. “There may be a risk of contamination,” he says. “However, while this may not pose risks for humans, it could be a problem for Japanese giant salamanders,” who are very sensitive to water quality. Yet, even if contamination is found, if it doesn’t violate legal limits, “we don’t know if it would be in farmers’ interest to protect water quality to the standards salamanders need,” Otani reflects.

Mount Daisen and fields
Fields in Daisen at the foot of the homonymous mountain © Sustainable Daisen
Mount Daisen in winter
Snowmelt from Mount Daisen feeds the Nawa River system and its beech forest cleans the water that flows downstream © Sustainable Daisen

JGS conservation faces murky waters on another front too. Tetsuya Yutaka of the Daisen Salamander Group, a small local organisation, points out that there isn’t enough data to prove that river infrastructure is impacting salamanders’ reproduction and lifecycle. Though data may be lacking, experts such as Takahashi and Taguchi have no doubt that concrete is causing damage. Habitat fragmentation is problematic for all endangered species, Takahashi explains, because “larger populations are divided into smaller populations and when animals exist in smaller, fragmented populations, they’re much weaker against natural or anthropogenic events that can cause their local extinction.” In addition, the chance of inbreeding increases in smaller populations and this can lead to inbreeding depression, i.e., the reduced survival and fertility of related individuals’ offspring. Reproductive behaviour is affected in other ways too. Taguchi emphasises that giant salamander breeding sites are rare and special, “so if they don’t reach these sites, sometimes they spawn in bad ones, such as hiding places they find under the base of weirs.” Apart from being far from ideal, these places are especially dangerous after heavy rain: “The typhoon season begins after the salamanders’ breeding season, so eggs often get flushed out of such bad sites.”

Weir along the Nawa River
Weirs along the Nawa River in Daisen, Japan © Sustainable Daisen

In Japan, torrential rainfall became more frequent between 1976 and 2020 and as a result of climate change, the intensity of tropical cyclones (known as “typhoons” in the western Pacific) is expected to increase in the future. Summer 2021 saw record-heavy rainfall in western Japan: in July, 330,000 people were evacuated in Tottori and neighbouring Shimane prefecture due to flooding caused by heavy rains and monthly precipitation on the Sea of Japan coast was the highest on record for August since records began in 1946. The presence of concrete structures in rivers where JGS live “makes heavy rain even more damaging than it would be in natural conditions,” says Pearce, because water flows more rapidly across concrete, therefore more salamanders are washed down and struggle to return upstream.

The Japanese giant salamander’s population distribution area in Japan, in yellow. Data: Hiroshima City Asa Zoological Park

Hybridisation with the Chinese giant

On 29 September 1972, a joint communique was signed in Beijing between the government of Japan and People’s Republic of China, normalising relations between the two nations. The following month, the first pandas from China arrived in Tokyo’s Ueno Zoo, welcomed by a grand celebration. Against the backdrop of the detente, another animal was also transferred between the neighbouring countries, though to much less fanfare.

Newspapers from the time detail how an Okayama businessman brought 800 Chinese giant salamanders to Japan to sell as food (a practice still common in China today). However, the Japanese government was opposed to this because, having elevated the JGS to national monument status, it couldn’t trust untrained people to distinguish between Chinese and Japanese specimens. Absent a business opportunity, the Chinese salamanders were released into Japan’s rivers and streams. “One was even found in the moat of the Imperial Palace in Tokyo,” says Taguchi.

Mixing between Chinese giant salamanders and native Japanese ones has since spread widely. This process, known as hybridisation, is considered a problem because one of conservation’s goals is to preserve genetic uniqueness. “Chinese and Japanese giant salamanders are genetically different but they can still interbreed and, when they do so, we lose genetic diversity between the two and, hence, the Japanese giant salamanders’ pure lineage,” says Takahashi. Kyoto and Mie prefectures in western Japan have been the epicentre of this phenomenon for decades, but new mixed individuals continue to be discovered in other parts of the country, including the first case in Hiroshima prefecture, which was found last year.

Japanese giant salamander_C_TopOutImages Yukihiro Fukuda
A Japanese giant salamander in a natural, free-flowing river © TopOutImages/Yukihiro Fukuda

Naoki Nakayama works for the Environment Ministry in Kagoshima, a prefecture on the southern tip of the southern island of Kyushu (a plane or strenuous train ride away from Daisen). From 2018 to 2020, he was the superintendent of Daisen-Oki National Park, whose 350,000 square kilometres of non-contiguous territory are divided between Tottori, Okayama and Shimane, and include JGS habitats such as Mount Daisen. Nakayama also worked on the ministry’s Red List and national laws to protect endangered species and says that one of the challenges with regulating the Japanese giant salamander is being able to tell the difference between native and hybridised specimens. Some experts even believe that “the hybridised population may be larger than the domestic one.”

On the other hand, Taguchi says no evidence of hybridisation has been found in over half of Japanese giant salamander habitats (though he also notes there aren’t enough researchers to study each area in detail). And Nakayama too highlights that no hybridised cases have been found in either Tottori or Shimane, which makes their populations especially important.

The Japanese giant salamander is considered an indicator species … It’s at the top of the food chain and the health of the salamander population is an indicator of the health and general well-being of the environment in which it lives.

Richard Pearce, CEO and founder of Sustainable Daisen

Japanese giant salamander_C_TopOutImages Yukihiro Fukuda
A Japanese giant salamander with its its eggs © TopOutImages/Yukihiro Fukuda

Local solutions to global problems

“Most species are extremely resilient to change. If one thing goes wrong, there’s usually a way around it, but the main problem is when everything goes wrong at the same time,” says Amaël Borzée, a professor at Nanjing Forestry University in China and an expert in amphibian breeding behaviour and conservation in North East Asia. Borzée is also deputy chair of the IUCN SSC Amphibian Specialist Group, a global network of experts providing the science to inform amphibian conservation. Together with the group and its chair, Ariadne Angulo, Borzée is involved in updating and publishing the Amphibian Conservation Action Plan (ACAP). First released in 2007, this is the first and only global conservation framework dealing with a specific taxonomic class, i.e. amphibians. The 2015 version, which was launched online in a “living document” format, is in the process of being updated. 

“Our current ACAP is a two-piece product: a piece that collates the science and from that, a shorter and more user-friendly document,” says Ariadne Angulo. “We have a vision for ACAP to act as a hub around which we can build a network of entities, such as businesses, organisations, even individuals (who can work together on conservation priorities).”


One aspect of the updated ACAP is to “start tracking what is being done, where and by whom, what has worked and what hasn’t,” because, in Angulo’s experience, “repeat errors” are sometimes made in conservation due to a lack of information sharing.

Photo above from the cover of the IUCN SSC Amphibian Specialist Group’s Amphibian Conservation Action Plan (ACAP) published in April 2015 by Wren, S., A. Angulo, H. Meredith, J. Kielgast, M. Dos Santos and P. Bishop. (eds.)

Richard Pearce acknowledges the importance of connecting JGS conservation to wider global efforts such as those of the IUCN. “As far as I know, we’re the only group concerned with Japanese giant salamander conservation that is taking an international view and trying to spread the word abroad.” While most conservation happens locally, “unless you’re able to integrate those local and regional problems into a global framework, you won’t know if these are isolated cases or part of a major pattern,” Angulo points out. Furthermore, local conservation actions that are informed by what is happening internationally “are much more beneficial because they’re backed by scientific evidence, even if it’s not specific to that locality,” Borzée adds. For example, if there’s evidence that certain factors are impacting a species, this could inform potential threats or conservation initiatives for other species in the same taxon.

Ariadne Angulo, chair of the IUCN SSC Amphibian Specialist Group
Ariadne Angulo, chair of the IUCN SSC Amphibian Specialist Group © Omar Rojas-Padilla
Amaël Borzée, deputy chair of the IUCN SSC Amphibian Specialist Group
Amaël Borzée, professor at Nanjing Forestry University in China and deputy chair of the IUCN SSC Amphibian Specialist Group © Yoonhyuk Bae

For these reasons, Pearce is keen to involve outsiders, and has planned for a professor from West Liberty University in West Virginia, USA, to visit Daisen and PIT tag as many Japanese giant salamanders as possible. Taguchi estimates that there may be around 10,000 salamanders left in Daisen, but a detailed population study hasn’t been carried out yet and because of heavy rains in recent years and the prevalence of weirs in the Nawa River system, many JGS are likely concentrated downstream. PIT tagging would contribute to gathering better data on JGS populations, but Borzée points out that the main threat to the species — namely, habitat degradation caused by river infrastructure — is already known. “We don’t have the luxury to wait to conduct research (before taking action).” 

Japanese giant salamander ramp construction_Sustainable Daisen volunteers
Sustainable Daisen volunteers, many of whom members of the US armed forces stationed at the Iwakuni Marine Corps Air Station in Yamaguchi prefecture. Others are students from Tottori University of Environmental Studies © Mara Budgen

Action is Pearce’s priority. In the early hours of a humid late summer morning in September 2022, he gave instructions to 23 members of the US armed forces stationed at the Iwakuni Marine Corps Air Station in Yamaguchi prefecture who had joined around ten other volunteers in Daisen. Pearce directed the volunteers to build ramps across four weirs (one for each weir) in a Nawa River tributary. Participants spent two days moving river stones and positioning wooden planks to construct the ramps that connect the riverbed below to the top of the weirs at an angle at which Japanese giant salamanders can climb up and, therefore, move upstream. “This is a huge chapter,” for Sustainable Daisen and JGS conservation, in Pearce’s words, and the organisation plans to monitor the slopes’ effectiveness by use of cameras and other tools.

Creating wildlife corridors that connect artificially separated habitats isn’t a new concept. For example, ladders that allow fish to migrate across barriers such as dams and locks are common around the world and bypass slopes for Japanese giant salamanders have already been adopted, albeit sporadically, in prefectures such as Kyoto, Hiroshima and Tottori, including in proximity of a flood control dam built in Daisen in 2021. “However, there are many weirs in rivers and streams all over Japan, so more slopes are needed,” says Taguchi.

Japanese giant salamander ramp by Sustainable Daisen
A Japanese giant salamander ramp in the Nawa River basin in Daisen built by Sustainable Daisen © Mara Budgen

The ramps built by Sustainable Daisen are the first in the Nawa River basin. Though they’re only temporary and the goal is for permanent ones with the proper engineering specifications to be built in this and additional locations, “this is a great success,” says Kazumi Pearce, who confesses she thought the ramp building would take three to five years to start, not a few months. Sustainable Daisen got permission for the structures from the local government, in part thanks to the help of Akihiko Nemoto, assistant dean of the department of Environmental Studies at Tottori University of Environmental Studies. As a forestry expert, Nemoto is adept at navigating red tape surrounding environmental projects.

Nemoto believes the ramps could snowball into a wider conversation. “If Sustainable Daisen succeeds in its strategy, it has a lot to say to local officials,” and in fact, some of these don’t hide their interest in the project. Yusuke Nakashima works for Daisen town’s tourism section and specifically for the Cultural Property Office: because JGS are a Special Natural Monument, this office is responsible for their administration and is engaged in PIT tagging and moving salamanders that are found outside of their habitat as well as consulting in case structural interventions, including but not limited to building sites, affect the species. “Daisen town is interested in understanding the effect that Sustainable Daisen’s ramps will have. It would be useful to conduct a study to see how many Japanese giant salamanders … are moving upstream or not,” Nakashima says, while clarifying that no such assessment is currently planned.

A Japanese giant salamander ramp in the Nawa River basin in Daisen built by Sustainable Daisen © Mara Budgen

Building wildlife corridors is a vital conservation strategy, but other factors are also at play. The situation is complicated by hybridisation, Taguchi says. “In Nara prefecture, hybridised animals use the ramps, so their habitat has become wider.” Furthermore, the obstruction caused by dams and weirs isn’t the only issue related to infrastructure. “Even with better connectivity between river sections, as long as there’s concrete banking, the situation is the same because this deprives the salamanders of nesting habitats,” Takahashi points out. “And that’s an even bigger challenge because we would need to break or get rid of concrete banking.”

Still, for Richard Pearce the ramps are an important starting point in Daisen. By building them, “we’ve gotten people’s attention, and we’ve gotten the local government to admit the weirs are a problem for Japanese giant salamanders and recognise that ramps are a way of remedying it.” 

Farmer meeting at Sustainable Daisen sanctuary, Japan
Richard Pearce (left) meets with local farmers who have agreed to lease their land for free for Sustainable Daisen to create a wildlife sanctuary and organic farming area in a key Japanese giant salamander habitat in Daisen © Sustainable Daisen

Despite his confidence, Pearce is aware that ramps aren’t a silver bullet and long-lasting conservation comes from changes at the ecosystem and social levels too. His NGO has several other projects, such as rewilding abandoned tree plantations to restore mixed forests, which are more biodiverse and hold more water than coniferous monocultures, therefore delaying the amount of water entering rivers during torrential rainfall. Sustainable Daisen is also working with local landowners led by Matsuda to create a wildlife sanctuary and organic fields in a 14,000 square metre area of abandoned rice fields where the organisation built its first ramps. 

Sustainable Daisen's vision and activities
Sustainable Daisen’s vision and activities © Sustainable Daisen

In the sanctuary, Sustainable Daisen aims to provide a food basket for Japanese giant salamanders (and humans) through chemical-free agriculture. “Organic farming is actually seen as selfish here,” says Pearce. “For example, farmers worry that wild seeds might get into the water stream and contaminate their fields.” By selling organic produce and promoting the adoption of this kind of agriculture, “we want to show farmers not only that it’s possible, but desirable.” Matsuda, who has been a farmer his entire life and has grown many crops, including organic rice, is giving advice on farming techniques. “I’ve been told that I’ll lose my eyesight in a few years’ time,” he shares. “I want to help out while I can still see.”

In its sanctuary, Sustainable Daisen aims to recreate the symbiosis between animal and human needs embodied in the concept of satoyama, literally “village” (sato) and “mountain” (yama). Satoyama are generally defined as dynamic mosaics of mountainous, forested and agricultural areas where humans’ harmonious interaction with the environment allows for preserving both biodiversity and natural resources to sustain livelihoods.

Akihiko Nemoto is interested in exploring the potential of sustainable local economies. “Sustainable Daisen’s rewilding and sanctuary projects bring together agriculture, forestry and tourism: part of the aim is salamander conservation, but the whole package is important.” Nemoto has brought a dozen of his students to visit the Daisen sanctuary: “I wanted them to see how economic activities in forests can go beyond mere forestry. What Sustainable Daisen is doing is cutting edge.”

Image above left © TopOutImages/Yukihiro Fukuda

Concrete state of mind

The idea of generating economic value from healthy ecosystems resonates with Nakayama and, in fact, linking conservation to local livelihoods is an official policy of the Environment Ministry. “We have to connect conservation issues to the economy for them to become a priority,” he says, adding that it was with this intent that the Japanese giant salamander tour in Nichinan was undertaken.

“(However), no nationwide project exists to protect Japanese giant salamanders,” Nakayama states. Conservation initiatives are dependent on local decision-makers’ and citizens’ will and “in rural municipalities, they aren’t necessarily prioritised because it’s difficult to allocate resources to them.” This is especially critical in places such as Daisen. The small town of quiet streets, fishing boats and endless fields is home to a shrinking and ageing population, which in turn is leading to economic decline and a more limited tax pool, thus fewer financial and human resources. In this sense, Daisen’s situation mirrors that of rural, depressed communities throughout Japan and the world over as these struggle to tackle big social and environmental challenges such as depopulation and biodiversity loss.

When it comes to Japan more generally, Richard Pearce believes change is hard to pursue even where young people are involved because they’re “scared of or prevented from pursuing new ideas.” This he attributes to the hierarchy between senpai (“senior”) and kohai (“junior”) prevalent in many Japanese organisations, schools and businesses, whereby juniors must always defer to their seniors. While it’s difficult to reduce the intricate web of interactions between younger and older generations to this simple hierarchy, it’s true that, on a systemic level, Japan often struggles to breathe new life into old approaches to social, economic and environmental issues. The construction state is a case in point.

Here, as in many other countries, “infrastructure is very much tied up with the idea of what development is, of what it means to be an advanced, industrialised country,” says Peter Matanle, senior lecturer in Japanese Studies at the University of Sheffield, in the United Kingdom. “Smart alternatives are there but people are often unaware of them or there’s disagreement at the local level … so there’s a tendency to fall back on tried and tested solutions which can be destructive and sometimes not even useful,” continues Matanle, who has studied the relationship between demographic change and resource consumption in Japan’s rural areas and is interested in understanding the role of depopulation and degrowth in environmental breakdown.

When Daisen’s weirs started to be built in earnest in the postwar period, “there simply wasn’t the kind of consideration for the environment and for giant salamanders that there is today,” says Tatsunobu Daikoku, who worked in the local government for decades. Positive steps have been taken since then: as well as salamander ramps being adopted in certain parts of Japan (though not systematically), Japanese law protecting cultural properties and guidelines in places such as Tottori prefecture require contractors to evaluate and mitigate the impact of construction on Japanese giant salamanders. Yet Pearce is doubtful that the fundamental approach to infrastructure has changed much. In his view, local authorities “have just carried on with business as usual,” as plans for the forest road in Nichinan demonstrate.

Forest road in Nichinan, Tottori, Japan
Construction of a forest road along the Hino River in Nichinan, Tottori © Sustainable Daisen

For example, in the 2017 documentary The River Dragon, which centres on Sumio Okada’s efforts to study and conserve Japanese giant salamanders, the protagonist speaks out against the practice of moving the animals when river works are carried out without properly relocating or PIT tagging them. Furthermore, “doing follow-up studies (of JGS) means revealing the damage that construction caused. It means admitting mistakes,” he says. “There’s resistance to that; some in local government may not like that.” In the documentary, a Nichinan town official goes on to admit that unless Japanese giant salamanders generate sufficient economic value, the local government isn’t interested in monitoring them or protecting their habitat — even though the town’s JGS population is a tourist attraction, as the Ossan Shouo mascot demonstrates.

Other issues derive from the way conservation is managed at the national level. The 1952 Special National Monument regulation sets a 500,000 yen (3,700 US dollars) fine for touching a Japanese giant salamander without a licence. But, to Taguchi’s knowledge, no one has ever been fined for violating this rule, which is difficult to police. Also, the legislation creates a paradoxical situation where only a few people are allowed to move salamanders even in cases where many have been washed downstream. More fundamentally, the problem with Japanese law is that it protects giant salamanders, but not their habitat.

Taguchi also highlights how in Japan “there are few national scientific government agencies responsible for giant salamander conservation,” in contrast to the Fish and Wildlife Service in the US, for example, which has scientific staff to research amphibians, especially those listed as endangered. Furthermore, local cultural offices in Japan, which have authority over JGS, tend not to be staffed with ecologists, biologists or conservation specialists.

A Japanese giant salamander with its eggs © TopOutImages/Yukihiro Fukuda

The problem is compounded by the fact that amphibian experts struggle with a lack of funding — with some, such as Okada, sometimes left to self-finance their work — even though the burden of raising awareness about salamander loss largely falls on them, Pearce says. “There’s even a risk that research may be impeded if it makes too much noise,” for example, by linking river construction to biodiversity loss, as Okada mentions in The River Dragon. In addition, Taguchi explains that Japanese giant salamander researchers submit periodical reports about their PIT tagging activities to their respective municipalities, but they “can’t access the government’s own data,” resulting in a continued knowledge gap.

“We (ecologists) have been frustrated by a lack of leadership in government in Japan, especially if compared to the initiatives of state and federal authorities in conserving hellbenders in the US,” Takahashi says. He also feels that it’s hard to communicate with public officials in his native country, in part because they periodically get rotated to new sections or departments, so even if a person has been educated on a certain issue, they’re soon gone. Kazumi Pearce knows this too well. “We had a good relationship with the Daisen Cultural Property Office representative, but they were rotated. Now we’re having to rebuild that relationship with the new person from scratch.”

Kazumi Pearce of Sustainable Daisen
One of Kazumi Pearce’s key roles in Sustainable Daisen is managing relations with local stakeholders, including government officials © Francesco Bassetti

On the backdrop of these issues is a general lack of awareness about the Japanese giant salamander’s decline — for example, Shinto priest Sumi visited the Nawa River with Richard Pearce to see salamanders stuck under weirs: until then he “hadn’t understood how serious the situation is and how fast we need to act.” Because of the existence of protective legislation and local conservation groups — which Pearce describes as “conservation groups in name only” — many, including in government, “think these animals are being looked after,” Pearce says. “But they’re not.”

One of the issues with conservation as a whole is that we tend to work in silos. But the bottom line is that if we want to move the needle, we need to start breaking down those barriers and start talking to new people.

Ariadne Angulo, chair of IUCN SSC Amphibian Specialist Group

Conservation is about working with people

“People need to know how public money is used,” says Yutaka of the Daisen Salamander Group. Therefore, if data can prove that Japanese giant salamander conservation strategies like bypass slopes work, “it would be easier to get funds.” However, Kazumi Pearce is doubtful the answer lies in data. It would be great to be able to show local residents a graph, for example, but that might not change anything because “people don’t necessarily care about numbers.” The challenge, she believes, lies in connecting people’s daily lives to salamanders and the threats they face. “If we can make this connection, attitudes might change.”

Japanese giant salamander_C_TopOutImages Yukihiro Fukuda
Conservation action could stop Japanese giant salamanders from going extinct © TopOutImages/Yukihiro Fukuda

The importance of stakeholder support is also addressed in the IUCN SSC Amphibian Specialist Group’s ACAP, which highlights the need for scientists to work with communications and behavioural change specialists to improve message delivery. In amphibians’ case, they are often undervalued if compared, for instance, to charismatic megafauna, even though “their benefits are much broader than we think,” says Borzée. “For example, do you know how the Wi-Fi signal you’re using was developed? The first algorithm is based on the call properties of the Japanese tree frog.” While fun facts like this may capture our imagination, the biggest problem for conservation scientists and advocates is that “people live in such artificial environments that it’s incredibly difficult for them to become aware of and relate to the tragic reality of what’s happening to biodiversity as a whole,” says Angulo.

The antidote is environmental education, which should begin as early as possible. “Sustainable Daisen wanted to donate one book about Japanese giant salamanders to every elementary classroom in Daisen, and we’ve managed to do that,” says Rachel Rasfeld, a Kyoto-based artist who is helping raise funds for the NGO by donating her paintings. “Not everybody will take action, but having people in the local community at least support the idea of action is important: it might seem like a modest goal but it’s an important one,” she adds. Sumi, who as well as being a priest is also the superintendent of the Daisen School District, agrees. “The aim is to educate children about Daisen’s riches and protect the environment where the Japanese giant salamander lives.”

A textbook about Daisen's nature distributed in local schools
A textbook about Daisen’s nature which is distributed in local schools. The Japanese giant salamander is pictured in the centre and lower left © Mara Budgen

Engaging with people requires adopting the right approach. Chen of ZSL, who is currently in Australia writing a PhD about conservation communication, points to the importance of publicly recognising the positive efforts being made by local stakeholders, rather than shaming them for past mistakes, to create a sense of responsibility and pride towards species protection. “Conservation action isn’t only about working with animals. It’s about working with people: we need to understand their psychology and community needs.”

Why the Japanese giant salamander matters

Chen, who has visited Japan to learn about giant salamander conservation, believes the situation in this country is more hopeful than in China because more people are aware of the giant salamander and invested in its preservation. In this sense, the fate of the JGS isn’t sealed. Whether its decline can be reversed or not constitutes a powerful case study relevant not just to Japan, but global conservation efforts.

One mistake that mustn’t be made is acting too late. Takahashi gives the example of the Japanese crested ibis (Nipponia nippon), or toki, whose Japanese population disappeared in the early 2000s and was brought back from the brink of local extinction: “If you reach that point, the amount of effort and money you have to put into conservation is ridiculous, and we can’t do that with every species. Now is the chance not to lose the Japanese giant salamander.” 

A Japanese giant salamander protecting its eggs © TopOutImages/Yukihiro Fukuda

Another point is the effect that social changes might have on the survival of Japan’s largest salamander. The JGS is a resilient species, as its long history shows, so as rural depopulation continues and entire swathes of the countryside are abandoned, “salamander numbers could recover,” says Taguchi. The researcher explains that in some cases in which weirs have naturally fallen into disrepair and have been destroyed, for example in Hyogo, salamander populations have been preserved. This is a small but real case of what Matanle calls the “depopulation dividend,” namely the achievement of positive gains, including environmental sustainability, from human depopulation.

Environmental dividends might include reductions in resource consumption, ecosystem and biodiversity restoration, and reduced waste and pollution.

Peter Matanle, Depopulation Dividend for a Shrinking Japan, Asia Global Online (2018)

However, Matanle points out that biodiversity restoration hasn’t occurred on a significant scale in Japan so far, even though over half of its land area has been depopulating since at least the 1980s. This is because the depopulation dividend doesn’t materialise spontaneously, but “needs to be harnessed, planned and implemented deliberately.” Depopulation is happening randomly, rather than systematically, and a lot of resources would be needed to remove infrastructure on a large scale. Therefore, this would require redirecting funds spent on construction towards deconstruction and “thinking carefully about what needs to happen,” once towns and villages empty out.

While better past coexistence between humans and Japanese giant salamanders shows that neither of the two species needs to be taken out of the equation for the other to survive, the complexity in obtaining environmental benefits from depopulation sheds light on the need to tackle environmental and social challenges as part of the same strategy. “If we really want to save this creature, we’re going to have to fix other broken parts of the countryside,” Richard Pearce says.

Japanese giant salamander_C_TopOutImages Yukihiro Fukuda
A Japanese giant salamander in a natural, free-flowing river © TopOutImages/Yukihiro Fukuda

How to help

There are many good reasons for conserving Japanese giant salamanders. These animals can be important boons for ecotourism dollars to flow into depressed rural areas and, as predators at the top of the food chain, losing them would have a cascade effect on the rest of the ecosystem. However, the most compelling reason, and perhaps the only one that can withstand the forces working against it, is that “losing the Japanese giant salamander would be a devastating indictment of human beings,” Angulo says. Takahashi agrees. “Knowingly letting them go extinct would really speak of our lack of humanity.”

The salamander’s future depends on enough passionate people generating enough momentum to trigger the widespread conservation action that has been lacking so far. In this sense, anyone can contribute by spreading the word about this animal little known outside of Japan, or supporting conservation organisations.

Richard Pearce, founder of Sustainable Daisen

“Could they die out? Definitely,” says Richard Pearce. “But I believe there’s hope because we’ve made giant steps in a relatively short time.” Looking to the future, he pauses to think about Sustainable Daisen’s goals for this year, which are crucial because each breeding season is key for stemming the flow of JGS decline. Having succeeded in constructing four temporary salamander ramps in a Daisen river, the next step is building permanent ones. “It’s a case of pricing them, getting official permission to have them installed, and providing the funding to do that.”

Sitting in the living room of their guesthouse, a traditional Japanese home near Daisen’s fishing port, Richard looks to Kazumi to gauge her reaction. “It’s difficult,” she sighs.

Richard is undeterred. “It’s difficult, but that’s the goal.”

This story was produced with support from Internews’ Earth Journalism Network.