The Hiroshima Hanzaki

By Rob Davis

I’ll admit it up front, I love amphibians! My foray into the world of professional ecology and conservation biology, was driven by a youthful passion to save the world’s declining frogs. It just so happened that I was an undergraduate student in the mid-1990’s when news was first breaking of the decline and extinction of amphibians world-wide. I remember reading articles about these declines, unprecedented in scale and was staggered by the fact that nobody knew why they were happening. The problem was so big that it threatened (and still threatens) the entire order of amphibians, and yet nobody I knew was working on frogs. I resolved that I would play my part and dedicate my studies to amphibians. I was lucky enough to undertake my PhD on frogs in south-western Australia and got to work on some  enigmatic and threatened frogs including the Sunset Frog, discovered in only 1994.


Sunset Frog Spicospina flammocaerulea (Pic: R.Davis)

Given my love of all things amphibian, I naturally have one on my wildlife bucket list. Topping this list, right there alongside tigers and polar bears, is the Japanese Giant Salamander Andrias japonicus. The Japanese affectionally bestow this species with the much easier name of Hanzaki. A member of the ancient family Cryptobranchidae, the Hanzaki has only two close relatives, the larger but much more threatened Chinese Giant Salamander (presumed extinct in the wild) and the near-threatened Hellbender of North America. Mysterious beasts, that have spawned many myths and legends, all members of this family are neotenic meaning that they retain juvenile features as adults, including gills and the ability to regenerate limbs.

I first heard about Japan’s surprisingly sizeable salamander on TV where I marvelled at pictures of the giant crocodile-like amphibian lurking in a remote mountain stream where it terrorised local fisherman and swimmers. I hoped then that one day I would be able to see this incredible creature in the wild. In 2014, I finally had the chance to make this dream a reality. When I was accepted to present at a conference in Tokyo, I carefully hatched a plan to add this amazing beast to my bucket list. My sleuthing tracked down a young researcher Yuki Taguchi in Hiroshima who kindly invited me to visit the captive breeding program that he runs at Asa Zoo. The zoo is a global pioneer and leader in breeding Hanzaki and breakthrough success in their captive program came through the use of enclosed tanks that simulate the holes in the river banks that Hanzaki excavate for breeding. Yuki’s studies have also highlighted the importance of understanding the social system of this species which lead him to give the dominant male (called the master) access to several females. This dramatically improved breeding success rates.


Yuki and the breeding tanks at Asa Zoo (Pic: R.Davis)

On my arrival at the zoo, I was very excited to see my first small Hanzaki inside the captive breeding tanks and to see a preserved specimen of the largest (documented) Hanzaki in the world, weighing in at 27.6 kg and measuring over 1.5 m!


The largest known Hanzaki specimen (Pic: Y. Taguchi)

The best news was yet to come, with the zoo extending me an invitation to join their monitoring program for wild Hanzaki in the Hiroshima countryside. Later that evening as Yuki and I drove through a verdant green landscape of rice paddies and lush native forest, he explained to me that most of the original streams in the region had been channelised and concreted for flood protection. This had created a big problem for Hanzaki as they could no longer burrow into the banks to breed. It also makes it harder for them to find cover and food. A further disruptive influence has been the construction of weirs to assist with flood regulation. This means that Hanzaki populations are now often isolated from one another especially as they are often unable to climb the large dam walls. Consequently, Hanzaki are often found with feet cut to pieces from trying to climb these concrete walls. One mitigation measure that Yuki and his team have undertaken is to install artificial breeding burrows at regular intervals in the concrete stream banks as well as alternative Hanzaki ladders to allow them to bypass large dams and move upstream. The Asa Zoo team also actively monitor population recruitment and move individuals if necessary.


A channelised and controlled Hanzaki stream near Hiroshima (Pic: R.Davis)

By the time we arrived at the first monitoring site, a small stream winding through open rice paddies and under a busy road, night had fallen and the air temperature had dropped. We met with two other vehicles and a small team of Hanzaki hunters emerged from the darkness, kitted up with head torches, nets and long poles for support in the fast-running mountain streams.


Asa Zoo Hanzaki hunter all ready to go! (Pic: R.Davis)

We headed off into the night along a short path through the rice field, and I quickly found myself on a riverbank. Clambering down the muddy, steep-sided bank, I took my first careful step into the icy cold, swift-running waters. It was quite an experience being chest-deep in water at night, carefully picking my way among uneven boulders, logs and other obstructions with my feet. My Japanese Hanzaki veteran and guide for the night was both faster and more agile than me, surging ahead and occasionally politely waiting for me to catch up, masking his wry amusement at my blundering progress. The main objective of our monitoring was to thoroughly search the stream as we travelled up it, using our head torches to try and spot Hanzaki below in the swirling waters. After perhaps an hour as my extremities were numbing from the cold and the gurgling water was soothing me into a sleepy stupor, I was beckoned excitedly by my assigned Hanzaki mentor (a lovely retired gentleman who has volunteered with surveys for the past 20 years). He pointed into a patch of water and said triumphantly “There, Hanzaki!”. Straining to make anything out in the swirling currents that refracted my light, I finally noticed that the large reddish log I was looking at was actually a Hanzaki!


Spot the Hanzaki (Pic: R.Davis)

I couldn’t believe the size of this magnificent animal, and how it managed to sit motionless so effortlessly in a current that was trying its best to sweep me off my feet. With an accomplished flick of his wrist, the Hanzaki wrangler placed his catch net in front of the ancient amphibian and ever so gently tickled its tail with his walking stick. The Hanzaki burst forward, but the Hanzaki master deftly twisted the net and hauled his prize catch to the shallower water near the bank. We readied all the measuring equipment and finally before my eyes, the wild Hanzaki of Hiroshima, my bucket list amphibian, emerged from he net for me to see of the first time. We measured it in a specially designed Hanzaki holding device (a PVC pipe cut in half!) before letting it go on it’s way. This one was about 80 cm.


The first captured Hanzaki ready for measuring (Pic: R.Davis).

I was thrilled with my first bucket list Hanzaki, but the night was young and to my great fortune I got to see and help measure a juvenile Hanzaki next. These are very rarely recorded and it is a sad reflection of the lack of recruitment in this population. No one knows for sure, but these denizens of the deep are thought to live for up to 100 years and are certainly known to live 30-50 years in captivity (the only verified record is 52 years). This doubtless means a slow generation time and combined with modern threats like changes to their stream habitat and introduced fish predators, there is concern that the viability of the Hanzaki population is declining. The IUCN accordingly lists Hanzaki as declining and estimates the population at 30-50 000 with an area of about 2000 sq. km of stream habitat occupied.


A juvenile Hanzaki (Pic: R.Davis)

As the night grew later and colder, we arrived at one final site, deep water at the base of a large dam wall, where Yuki had previously captured some larger adults. Although he told me that it was extremely rare to find many animals close to 1.5 m and that most are around 80 cm, he said we had a chance of seeing a Hanzaki over 1 m if we were lucky. After only ten minutes of surveying at this site, an excited call went up and we all rushed over to help one of the team net a larger animal. We readied the measuring equipment and as Yuki pulled the Hanzaki from the catch net, I gasped in excitement as the largest Hanzaki I was ever likely to see emerged from the water. This was the animal of legend that I had heard about; and it really did take two people to handle it!


A 1.2 m Hanzaki!! (Pic: R.Davis)

We measured this amazing animal and as we did, I couldn’t help but notice it’s tiny white eyes fixing me with an unblinking stare, and its incredible skin with gravel-like protrusions that helped it blend in perfectly with the rocky streambed. This gargantuan Hanzaki measured in at a little over 1.2m!


The eye of the Hanzaki! (Pic: R.Davis)

I was given the great honour of releasing this big old Hanzaki back into the water. As I gently placed it into the stream with the summer stars shining brightly above, it gently flicked it’s tail and disappeared into the dark swirling waters.


Rob living his bucket list dream, about to release a Hanzaki (Pic. Y. Taguchi).

I hoped that this wasn’t the last I would see of the Hanzaki and that it would be there for my young son and future generations to see. There is strong cause for optimism, with community support and village-based Adopt-a-Hanzaki schemes proving successful in raising awareness of this species. Hanzaki are protected by Japanese law and faring considerably better than their Chinese cousin which has been virtually exterminated from the wild for serving as a restaurant delicacy.  There is still much to be done, but the Japanese consider the Hanzaki a lucky charm and are engaged in its conservation. As I flew out of Hiroshima the next day, I gazed down at the streams running across the forested landscape and felt positive about the future of the Hanzaki and extremely lucky to have had an encounter with one of the world’s most amazing amphibians.

Battling ignorance in the media

The views expressed herein are those of the author and do not represent the opinions of any other party

A critique of Paul Murray “Green Tape Fails Public Test” The West Australian 21/8/2016.

By Rob Davis

Sometimes something comes along that is so ludicrous and ill-informed that in the interests of battling ignorance, it requires a response. This article by Paul Murray in The West Australian is one such occasion. Although it is very disappointing that such a non-informed beat-up was published, it is passed off as an opinion piece which therefore precludes the need to be factually accurate. Scientists don’t have that luxury in our formal writings and although anyone can have an opinion, it can be contended that it’s not worth listening to if it isn’t based on evidence. Unfortunately many people in society form views based on the uneducated opinions of people who are given a populist platform, and not from scientists who can present rational and evidenced arguments. Scientists have to take some blame for this as we are often reticent to appear in the popular media.

What follows is a critique of the aforementioned article by Murray. My only objective in critiquing it is both to redress the mis-information presented therein and to hopefully also draw attention to the need to ask for the evidence when reading these sorts of opinionated articles in future. I hope it also leaves the reader asking why newspapers are giving any space to this sort of thing.

Murray starts off his piece in an assault against ground-water dwelling invertebrates and makes the following key points about them:

  • Stygofauna and Troglofauna have no beneficial human use and are only of academic interest
  • Do we know that the existence of a certain type of invisible fauna would be threatened with extinction by mining if we haven’t looked for its presence everywhere else?
  • And if we didn’t look for them, would they exist at all in our consciousness?
  • While greenies are happy to use the technicalities of the Environmental Protection Act to stop a uranium mine, others might question whether the law has become ridiculous in terms of overriding the public good.
  • Where’s the real social benefit in preserving an isolated colony of stygofauna which may well exist everywhere under unexplored desert areas?

Murray sets up a philosophical standpoint that he perceives these stygofauna species to be of no benefit to humans and therefore they should not exist or be interfering with the approval of a proposed uranium mine. This ancient resource-focussed rhetoric is unfortunately exactly what got us in to the biodiversity crisis in the first place. Ironically, it is also often native species most beneficial to humans that are the most threatened. Murray presumably has no experience in stygofauanal ecology and in writing this piece, has apparently not undertaken even a lazy google scholar search about his topic of choice. I did so (having no stygofaunal expertise) and my very first hit was no less than this Australian paper exploring the ecosystem benefits of stygofauna including their likely role in purifying the water that we drink, assisting its infiltration and in bioremediation from the exact sort of mining Murray is so in favour of. In fact Boulton et al. (2008) go as far as to state that the loss of these stygofaunal communities through human disturbance may lead to a collapse of the ecosystem services they provide and could actually lead to the loss of the entire aquifer for human use. Can we justify the loss of a perpetual resource for millions of people and industry for the short-term monetary gain of a single mining company? The fact that I so quickly found a counter to Murray’s argument further suggests why we should place so little value on opinion pieces when the authors spend no time at all researching their topic and are therefore speaking from a personal conviction rather than fact.

Ignoring the obvious technically incorrect use of the word “invisible”, Murray’s second argument is that old chestnut used by developers the world over – losing this stygofaunal population probably won’t be an issue as they are likely to be found elsewhere. There is a fundamental concept in ecology taught to first year undergraduates, called “the precautionary principle”. It surmises that until we can be sure that the outcomes of our actions will not have a negative impact, we should not undertake them. Would Murray have us lose these species and this potentially unique community on the off-chance that they may one day be found elsewhere? The argument also ignores the existing science around the extensive surveys that have been done throughout much of the Pilbara and Mid-west in recent years both as part of bio-regional surveys and by private consultants.

The most preposterous argument of all is next. If we don’t know about or look for stygofuana do they really exist? Murray holds this up as a trump card to further his argument on this perceived ludicrous situation of invertebrates stopping a mining development. The very argument advocates ignorance, imploring us to simply not explore the natural world for fear of discovering things that might one day interfere with a development or negatively affect our lives in some way. Fortunately, science is based on curious exploration and has subsequently allowed us to discover many things we can’t see but know are important including oxygen, understanding the emergence and existence of life on earth and the very nature of gravity and time to name a few.

After dismissing that anybody with a passing interest in the natural world is clearly a “greenie” including presumably all highly qualified ecologists, Murray sees the discovery of this rich, diverse and endemic stygofaunal community and it’s triggering of the relevant legislation (which ultimately resulted in advice to not proceed with the development) as a frivolous technicality. He also clearly feels that the extinction of this community would be in the public good and that society would much rather be mining and exporting uranium (which I’m sure if he researched he would find the weight of public opinion to not be on his side).

In response to his point “where’s the real social benefit in preserving an isolated colony of stygofauna which may well exist everywhere under unexplored desert areas?”, I have already addressed this. There would appear to be enormous social benefit in preserving this stygofaunal community, both for its ecosystem services in maintaining a usable water supply, for its uniqueness and evolutionary significance and because unlike a short-term mining windfall, it is gone for the rest of time once eliminated. Murray again uses his extensive ecological knowledge to suggest to us that the stygofauna likely exist elsewhere anyway. It’s interesting that Murray feels there must be a social benefit for something to be relevant or allowed to exist in this case.

Murray’s ramblings on land-clearing are equally if not more illogical and factually flawed. Murray contends that regulators are over-zealous in wanting to reduce or prevent land-clearing on farms. Murray again failed to do even the most basic of journalistic research in which he would have discovered the recent declaration by 500 scientists calling for an end to the out of control land-clearing by farmers and developers in Australia. Our recent zeal for habitat destruction has earned us the unenviable title of the only developed country amongst the world’s 11 largest deforestation offenders. We already hold the world record for mammal extinction with 30 species lost since European settlement. Although predation is a leading cause of mammal extinction in Australia, for all animal groups worldwide, research has shown unequivocally that habitat loss from logging, farming and urban development is still the major driver of extinction.

The saddest injustice in all of this is that most farmers that I have worked with, couldn’t be further from the view that Murray puts forward, with so many of them deeply engaged in revegetation and restoring species. The most staggering oversight of all is that Murray fails to understand that we are arguably the worst place affected by cropland salinity on earth. Again this is a very well documented and studied topic. Even aside from the biodiversity consequences, it is having a large impact on rural productivity and livelihoods. The primary cause of this problem – land-clearing! That is the precise answer to why farmers are denied the right to clear vegetation on their properties – because it’s an absolutely terrible and archaic idea that is thoroughly evidenced by science.

Murray invokes a third person narrative about a farmer who could not clear his land due to the presence of the endangered Carnaby’s Black-Cockatoo. Murray fails to outline that this species is endangered and its listing under the federal EPBC Act automatically protects its critical feeding habitat and that this is assessed by expert ecologists and undergoes a rigorous review process. He also seems shocked that the cockatoos seem to have rights when farmers apparently do not. There is little point in further arguing this one as Murray clearly also is against endangered species or their habitat being protected and has no faith in the scientists who asses the feeding habitat. It seems that anything not supporting a development outcome is given short shrift. An unnamed “reliable witness” is invoked to put this point forward. The comment about 50% of the shire remaining uncleared is also not substantiated by evidence and the quick search I undertook revealed that only 13% of native vegetation remains on private properties in the shire.

In closing Murray quotes a pearler “The DER should not be able to deny property owners the right to clear native vegetation unless it can be shown, with substantive evidence, that specific environmental damage would result from such action,” Mr Blumann says.”. As we have comprehensively outlined, it would appear very well known to mostly every ecologist and environmental managers in the world that vegetation clearing has catastrophic effects. It is arguably the most documented single fact in modern ecology.

Lastly, Murray contends that the decision to halt the uranium mine is a “perverse mis-use of science”. An interesting argument when his whole article has been a perverse mis-use of logic and a failure to cite or consult any science! I am pleased that people like Murray are not involved in important decision-making and only regret that there is a soapbox provided to such ignorance and blustering opinion. I hope that next time, Murray will consider either consulting some actual scientists, researching the primary literature or best of all, stick to topics that he has some sort of expertise in.