This article is the first in a series on biodiversity. A United Nations meeting on biological diversity began virtually this month and will conclude in person next year in Kunming, the capital of Yunnan province. View the entire series here.

HUNAN, Central China — While Jiang Wansheng swiftly unearths a hat and fishing nets from the trunk of his SUV, he urges his students to hurry up. “We have to get everything out before any tourists arrive,” he says.

It’s a humid summer morning, so early the sun has just begun lighting up the sky, and the vast parking lot of Zhangjiajie National Forest Park, famous for its pillar-like rock formations, is still empty. But visitors are sure to come. If they see what Jiang’s team is up to, they might mistake them for poachers and call the police.

Together with six of his students, Jiang, a biologist at Jishou University’s Zhangjiajie campus, has spent the past two months skulking through the mountainous areas around the city in the hopes of finding any sign of a critically endangered animal: the Chinese giant salamander.

The water-dwelling predators are the world’s biggest amphibian — up to 1.8 meters long — and tens of thousands of them once thrived throughout all of China’s major river systems. But they’ve been hunted to near extinction, and extensive reintroduction campaigns have been hampered by a lack of research and little monitoring. Meanwhile, a recent discovery that the salamander is genetically much more diverse than was previously believed has raised the question of whether repopulation efforts are doing more harm than good.

One thing conservationists all agree on is that the number of giant salamanders in the wild remains perilously low. The precise figure, and which way it is trending, is unknown. Jiang and his students have trudged through mud while dodging cattle dung to set traps, and they have made nighttime treks, wading through streams in hip-high rubber boots to inspect small caves between rocks — the nocturnal animal’s favorite hiding spot. Despite these efforts, they have yet to see one.

But Jiang is confident that they will finally find what they’re looking for in the Gold Whip River, which flows through the national park. Patrolled by rangers to keep people at a distance, the river is a safe haven for giant salamanders, Jiang told Sixth Tone the night before, when the team set up a dozen traps filled with pig organ meat.

While retracing their steps in the early morning light, however, the team encounters another string of failures. Two cages have trapped nothing but some curious crabs. Others were tossed into the trash by oblivious park cleaning staff. But then, finally, they have a catch. “I’m glad we won’t go back empty-handed,” Jiang says, visibly elated. Inside a trap, strategically placed under a pile of river boulders, sits a decidedly unappealing animal, its body an elongated blob the color of feces that ends in a big and flat face with barely noticeable eyes. Unmistakably, they’ve caught a Chinese giant salamander.

Yet, at the same time, Jiang has no idea exactly what animal he’s looking at. In 2018, Chinese and British biologists concluded that the Chinese giant salamander is not one, but at least five different species, each native to separate parts of China. A year later, another team of researchers reached a similar conclusion, identifying at least seven distinct lineages. But by then, the government’s so-called enhancement efforts to increase the giant salamander’s wild population by releasing farmed animals had unknowingly redistributed individuals of the various species all over China.

This messy state of affairs has made the question of how best to preserve wild giant salamanders a divisive topic among the small number of scientists who study them. With the different species now living in each other’s habitats, they could possibly interbreed and end up creating offspring genetically similar enough to actually become one species — as if stirring together different paints until they turn into one color. While some argue mixing the genomes will produce stronger individuals, others decry the potential loss of biological diversity and say artificial breeding and reintroduction campaigns should be suspended until the animals are better understood.

Jiang’s research focuses on mapping which lineages of giant salamanders can now be found in Zhangjiajie. As his catch oozes a slimy mucus, a sign it is distressed, Jiang puts on a pair of latex gloves and, careful not to get bitten, gently moves the roughly meter-long brown creature from the trap and into a fishing net. Having forgotten to bring the cotton swabs from the car in the morning scramble, he had to improvise and instead take a little bit of tail skin, which the team will use to study its genetic make-up. Then they release their sole catch of the summer back into the water. “It’s a good sign that some giant salamanders are thriving, at least in this well-protected region,” Jiang says. “It’s either a wild individual, or it must have been living in the wild for a long time — enhancement projects don’t release animals this big.”

Giant salamanders are unorthodox in many ways. “They have so many secrets for us to unlock,” Jiang says. They are, for one, much larger than other amphibians. They are apex predators but lazy hunters, preferring to stay hidden and grab food as it swims past. Living mostly underwater, the animals only surface to breathe, which they do through their skin. They can regenerate tissue when wounded. It’s a formula that has withstood the test of time. Chinese salamanders have existed for 170 million years — since before the age of the Tyrannosaurus rex — and have remained largely unchanged.

But their numbers have cratered in recent decades. When Zhangjiajie native Chen Gongming was young, he often played in the Lishui River that flows through his hometown, Wudaoshui, located northwest of the national park. They would sometimes catch salamanders to eat or sell. “I remember seeing at least three giant salamanders every time I went to the river for a swim,” the 64-year-old tells Sixth Tone. Those days are long gone. “It may have been nearly 10 years since I last saw one in the wild,” he says.

In the late 1980s, as the Chinese economy began its decades-long run of rapid growth, people began to view giant salamanders not just as a supplement to meager rural diets but as a delicacy. Chen decided to quit his construction work and use his savings to build breeding facilities in Wudaoshui. In 1987, he captured 28 wild animals from the river where he used to play and became the third licensed giant salamander farmer of Hunan province. Then, as now, salamander farms are little more than barely lit concrete basins. The animals are low-maintenance and aren’t picky eaters. Chen feeds them frozen fish and chicks.

In Chen’s cavernous office, located above one of his eight breeding facilities, one wall traces his rise. A yellowing photo in which a much younger Chen holds a giant salamander hangs next to a collection of gold-colored plaques from the local government praising his farm. In a picture from 2013, a neatly dressed Chen poses proudly next to a local government official. Back then, the animals’ price reached high after new high, at one point topping 4,000 yuan ($620 by today’s exchange rates) per kilogram. Scientists now say that is one reason why the animal remains understudied. For a long time, they couldn’t afford to buy salamanders for observation. But Chen was having a glorious time, making a million yuan every month selling salamanders to restaurants and hatchlings to other farms, he recalls.

Sales shot up, but farmers’ concrete basins weren’t conducive to reproduction. To maintain stocks, many turned to poachers. Hunting the animal had required official permission since 1988, when China placed giant salamanders on its protective species list. But enforcement was weak. As a result, the Chinese giant salamander population crashed. Since 2004, the animal has been considered critically endangered because of a “drastic population decline, estimated to be more than 80% over the last three generations,” according to the International Union for the Conservation of Nature (IUCN). “That’s in line with the fate of many other amphibians,” says Amaël Borzée, a biology professor at Nanjing Forestry University in eastern China and the deputy chair of the IUCN Species Survival Commission Amphibian Specialist Group. “Amphibians are not very sexy obviously, so not a lot of people care about them,” he tells Sixth Tone.

More recently, the price of giant salamanders has plummeted. Better breeding methods have increased supply. But demand has also dropped. When the COVID-19 outbreak was linked to the wildlife trade, the government began to reconsider the farming of all kinds of animals. Though aquatic animals were exempted from a later ban, consumer attitudes had shifted, Jiang says. Zhangjiajie, in February 2020, did institute a local ban, wiping out a third of Chen’s sales. He feels aggrieved and confused. The city’s government had earlier promoted the industry as a poverty alleviation tool. His salamanders are now priced at around 100 yuan per kilogram and cheaper still when bought in bulk — a far cry from what he was making twenty years ago. “I have invested 50 million yuan in my farms, but I’m losing money every day now,” he says.

To some, farms like Chen’s are part of the problem. The dual status of the Chinese giant salamander — wild populations are protected while farmed animals are legally traded — makes conservation work challenging, researchers say. “It’s hard to talk about protection when business interests are involved,” Che Jing, a biologist at the Chinese Academy of Sciences’ Kunming Institute of Zoology, tells Sixth Tone. Chen, the farmer, argues that, without hatcheries, giant salamanders would rise in value enough for poaching to once more become worth the risk. Also, because farms supply the government reintroduction efforts that, since the early 2000s, have attempted to keep wild giant salamander populations from collapsing, the animal would truly be in trouble if Chen and his competitors quit, he says.

But these programs are not without controversy. The discovery of the genetic differences meant that, for years, farms had unwittingly been running interbreeding experiments by making giant salamanders of different lineages produce offspring. “We should suspend all release programs until we can answer some of the questions about these animals,” says Che, who is one of the 2018 paper’s lead authors.

That includes agreeing on whether the differences between the lineages are big enough to call them different species. In biology, such delineations are never clear-cut. Conventionally, two animals are classified as different species if they cannot mate, or if they produce infertile offspring — such as mules, the progeny of a horse and a donkey. But some biologists, using modern technologies, argue that animals should be classified as different species if their genes are divergent enough, which, Che says, is the case for giant salamanders. “Some groups split off from the others as early as 10 million years ago,” she says, adding that this is about when humans and chimpanzees went their separate ways. “In fact, my current study has found signs that some lineages can’t interbreed. But regardless of whether they can be defined as separate species, each independent lineage should be protected independently.”

Further study into the different lineages is complicated. “The most pressing issue is that even though we find there are separated groups of giant salamanders, we’re yet to be able to determine the exact geological range of each species,” Che says. It’s also unknown whether giant salamanders of different lineages are mating outside captivity. A mixed-heritage individual in the wild may have been born on a farm. The worst-case scenario, to some, is that the various lineages do breed on their own initiative. Eventually, this will reduce their genetic diversity, and they will potentially produce offspring that is infertile, as many hybrid animals are. It could spell the beginning of the end for the giant salamanders.

But Diao Kunpeng, the founder of nonprofit Qingye Ecology, which helps manage nature reserves, says academics tend to overrate the importance of genetic purity. “I think the focus of conservation should be to make sure the giant salamander exists in water to play its role in the ecosystem,” he tells Sixth Tone. Besides working with giant salamanders, Diao has years of experience protecting giant pandas. He says conservationists in that field are also split on whether China’s two panda lineages — one home to northern China’s Qinling mountains and the other hailing from the southwestern Sichuan province — should interbreed. “Genetic purity is certainly something we should pay attention to and be aware of,” he says. “But now there are places that would rather leave their rivers empty rather than try to restore the ecosystem. Personally, I think it’s being penny-wise and pound-foolish.”

Jiang, the Zhangjiajie researcher, also thinks the survival of giant salamanders as a group should be the priority. By definition, genetic homogenization reduces biodiversity, but, Jiang explains, breeding between lineages may introduce hybrid vigor, a biological phenomenon that occurs when genetically diverse parents produce offspring with improved performance. “Is it really that scary? We have no data to say either way,” Jiang says. “Mixing already happened, and it wouldn’t be rational or ethical to clean out all the non-native animals. So I think the most pressing issue is to figure out whether there is actually a threat or maybe an unintentional benefit.”

Finding these answers is a slow process. Scientists like Jiang, whose work is funded by the Zhilan foundation, a private organization aiming to protect endangered species, need to trap animals to gather their genetic information. Research could be sped up if giant salamanders released into the wild were fitted with devices that relay their movements and whether they are alive, as commonly happens with other large animals. But technological difficulties and lack of funding mean this rarely happens, according to Chen Jiafa, the head of the Zhangjiajie Giant Salamander National Nature Reserve Management Bureau.

The bureau oversees most giant salamander conservation and release activities in the reserve, which covers an area of 140 square kilometers and includes the national park. Chen Jiafa, who isn’t related to Chen Gongming, tells Sixth Tone that salamanders like to squeeze into cracks between rocks, so external trackers — such as the collars put on bears — aren’t an option. The bureau has been trialing chip implants, but recording the activities of the salamanders this way requires installing thousands of signal sensing stations along the reserve’s rivers. “It’s an expensive project, and we’re not in a position to make such investments for now,” Chen says.

The lack of tracking also makes it difficult to evaluate protection efforts. Chen Jiafa has been trying to improve how giant salamanders are reintroduced into the wild. After scientists argued the animals should be trained before they are released from their concrete farm basins, he built an outdoor pond that mimics the natural environment. There, the salamanders are fed only live fish and shrimp which they have to catch themselves. They are reintroduced into the wild after six months to a year of such training — and after a genetic analysis to make sure they are native to the area. But without proper monitoring, there’s no way of knowing whether this translates into a higher chance of survival.

In general, it’s an open question whether releasing giant salamanders into the wild is effective. Jiang Jianping, an amphibian researcher at Chinese Academy of Sciences’ Chengdu Institute of Biology, estimates that, by 2019, the number of individuals released into rivers and streams across the country totaled over 270,000. But wild giant salamanders are rarely spotted, making it a mystery where the released animals have gone. “I’ve been doing field research at many places for many years, but never really see a wild salamander,” Jiang Jianping, who isn’t related to Jiang Wansheng, tells Sixth Tone. After two decades of repopulation programs for Chinese giant salamanders, authorities and scientists alike are uncertain about what they have achieved.

Frequently, giant salamanders are released to make construction projects environmentally neutral. In 2019, for example, a billion-dollar high-speed railway line opened that connects the southwestern metropolis Chongqing with Changde, a city in Hunan. The line cut through forested mountains and necessitated the construction of several concrete pillars in the waters of Zhangjiajie’s giant salamander nature reserve. To compensate, the builders contracted Chen Jiafa to release some 900 Chinese giant salamanders into the reserve.

Over the past decade, the bureau has undertaken over 50 such compensation projects, each time releasing dozens and sometimes hundreds of giant salamanders into the reserve. How the animals are faring, or where they are, nobody knows for sure.

Correction: A previous version of this article said Diao Kunpeng works at Shanshui Conservation Center. He has taken up a new position at Qingye Ecology.

Contributions: Nie Yiming.

(Header image: A Chinese giant salamander inside a hatchery operated by the Zhangjiajie Giant Salamander National Nature Reserve Management Bureau, Hunan province, September 2021. Wu Huiyuan/Sixth Tone)