Down Under Down Under: collecting in the dark zone

Video | Updated 3 months ago

Authored by Dr Bill Humphreys
Presented by Dr Mark Harvey

Presented as part of the In the Wild West Lecture Series in 2012.

Beneath our feet lies a hotspot of subterranean biodiversity. Hear about the lengths our curators go to - from fishing down boreholes in the desert to abseiling, crawling, hammering, digging and cave diving - to collect specimens for the State’s collection.

Transcript

Thank you Felina and good evening everyone.

I'm terribly apologetic if you really thought you were going to get a great talk from Bill. You're going to have to put up with what I'm able to cobble together.

As Felina said, Bill's unwell and I did get the thumb drive with his presentation from his family at 11 o'clock last night, and I managed to print it out this morning and take a look at it. I haven't had a chance to practice it, so we're just going to have to see how we go. So, bear with me.

Bill's title, as Felina said, is 'Down Under, Down Under - Collecting in the Dark Zone'. Bill is an international authority on the ecology and biology and taxonomy of subterranean organisms here in Australia, and he's really done a remarkable job in discovering this fauna. Huge numbers of new species, communities of subterranean organisms that we didn't know existed 15-20 years ago, and popularising that information and summarising it in a scientific way.

So, I've crossed out his name there. It's actually being presented by me. So I'm going to see how we go here.

Now, the core of all museums around the world are collections. Without collections, museums are virtually nothing. There are all sorts of questions that you can ask of collections, and how you input into making collections in museums. What sorts of things should you be out there getting representatives of to include inside museum collections?

Once you have those collections, it feeds off into a number of different areas. One of those can be research - which I'm going to talk a little bit about today. This is an example of some research. This is a phylogenetic tree of different organisms and how they're related to each other. These can feed off to collections and their research can feed off into displays that you'll see in museums. Information that can be provided to government agencies, industry, and to the public, because a lot of what we find during our research is of intense interest to other government agencies - DEC, Environment and Conservation, the Environmental Protection Agency, and of course industry, who intersect with some of these habitats where subterranean organisms occur. Also, they can feed off into publications, and here's some examples here of some monographs and scientific papers that we've published.

Now, this is an example of display settings. These are more modern dioramas you might see in something like the Field Museum in Chicago, and nice little dioramas like this. This is the more old fashioned type that some of you might have seen as kids, and if you'd visit some of the European museums, you can actually still see some of these sorts of cabinets today, which I must confess, I absolutely love these sorts of things. They really tickle me.

So what we're going to be talking about for a while here is the research side of things. Now, in studying subterranean organisms, one of the things that Bill's been able to discover over the years is, as I said before, the vast numbers of new species, and these subterranean animals often look quite different to their relatives that might be living in the surface environments. So this is an example of a small freshwater crustacean, an isopod - a slater, as I call them when they're in my back yard. I come from Melbourne. So we used to call them butcher boys as kids. I have no idea why. I've got no idea what a butcher boys and nobody elsewhere in the country seems to know what a butcher boy is, so may be it was a Melbourne thing.

This is a standard sort of shape that you would get in this genus, but this is an example of one of these animals that's become modified for subterranean life. You can see it's longer and thinner in comparison to the one that lives on the surface. It has no eyes. The legs, the antennae and the other appendages have become quite long, and this is a very standard adaptation to living underground, and we'll see some of those later on in the talk. This is what a description of one of these would look like if you're doing a scientific research publication, to actually describe it as a new species. So you can't just think up a name for a new species, take a photograph of it, chuck it up on the internet and hope everything goes well.

You actually need to do a huge amount of research and write a taxonomic paper of which these rules and regulations that Felina just mentioned before, this rule book that I'm involved in, the Commission that regulates those rules, one of the things is you need to document the morphology carefully. So these are drawings by our colleague Stefano Taiti who works in Italy, who works on these animals. This is the top drawing of it, this is the face, these are some of the appendages here, and in most cases, different species will have different shapes to all of these appendages, and this is how we define them. So it's a very long, time consuming task.

In terms of collections and how we put them on displays - so museums routinely have large research collections which are housed away from generally the public eye. People don't get to see them. They are literally research collections. They're not particularly displayable. They don't look all that fantastic, especially when they're only one or two millimetres long inside a glass vial. But you can see examples here of modern museum collection storage areas like this. These are some drawers of some insects. These are compactus systems where all the jars are sitting in an alcohol store. But nowadays, there are moves to start putting some of these on public display, without much interpretation, but people can just wander around and take a look and see what a museum collection might look like, if you were behind the scenes.

Now this is where once the collections are made and they come back into the museum, this is where they're sorted in a laboratory situation using a microscope. Jars and jars and jars of the things might be collected on an individual field trip. So the question that we can pose from these collections is all sorts of interesting aspects - How many species are there? Where do they occur? What are their evolutionary relationships? Who did they evolve from? And then at the final end, once we know where they are and what they are, we can then start ask questions, questions about their ecology and also how they intersect with things like the mining industry who may wish to dig up that area where something might occur.

Now, subterranean environments come in many different shapes and sizes. The most familiar one you might be aware of are caves, where you can walk into the area. It's big enough for a human to crawl into or walk into. Some caves are enormous. Some of the show caves are spectacular. But caves are basically voids - underground voids - and can be formed - they're mostly formed through water travelling through a soluble sort of landscape. So limestone is a very, very good example where water slowly erodes the limestone away to cause these spaces. Now these spaces are often habitable by small animals and big animals. You get bats that might be able to fly in there and roost, but you also find lots of other things living in the voids that have moved down from the surface.

This is an example of a limestone cast. Cast is just a word for an area that might form sort of cave type systems. This is a cast system in the Kimberley, and you can see that this really strong weathering process where the limestone just dissolves away, in this case from rainfall, and in the past this was originally a Devonian reef system. This is actually made up of limestones of lots and lots of tiny little marine organisms that died 350 million years ago, fell on the reef. When they all died, they compacted and now they've formed this solid rock matrix, which has been uplifted and is no longer under water, and forms this cast where there are lots of gaps and holes where animals might survive.

Now this is a cross section - a hypothetical cross section of a bit of a mountain where you can see all sorts of different things going on. I guess the take home message is you get large holes in the ground where things can fall in, including debris and animals. Sometimes at the bottom of these steep ones you might find things like dead kangaroos and pigs and things. They can form lateral voids in the ground like this, but also most interestingly - and I'll get back to that later in the presentation - there are these very small caves or sorry, voids in the ground where we can't get into, but where there are lots of interesting things happening in terms of new species of animals, and we'll talk about that a bit later in the presentation. You can also see here that there's a big division between the voids that are filled with air. So you have air breathing animals which are called Troglofauna when they live underground. They still breathe air. So most of the insects, arachnids like spiders and scorpions and their relatives, cockroaches, will all live in this area.

There's also the aquatic environment, the aquatic underground environment, and animals that live in these sort of systems here are called Stygofauna, and they include mostly crustaceans - so amphipods and isopods - I'll show you some later on - but we also get things like diving beetles that live in here as well. So Troglofauna breathe air. Stygofauna live in the water at the bottom of these systems.

Now in Australia, there are all sorts of different cast areas, so called hard rock casts, soft rock casts, volcano castic areas and calcrete aquifers. You can see that there are different types of cast systems around the country, and Western Australia has got a relatively large area of casts. The most obvious one if you've ever taken the trip across the Nullarbor and looked at some of the caves through there, is the Nullarbor Plain region which forms some very large caves. We also get these calcrete aquifers that form along these paleodrainage river basins in the inland.

Now most of these rivers actually drain inland, they don't drain out to the sea, and they're very, very old. Limestones are deposited in the floors of these large rivers. They've been there for millions of years and we're finding a lot of fauna that's actually adapted to living in that limestone, in that cast area, which we didn't know about 10 years ago basically. You also get a little bit of cast along the coastal area here. There are caves down in limestone areas - places like Margaret River and Augusta region, the Leeuwin Naturaliste Ridge, Yanchep has some lovely caves - some of you have probably been into them - all the way up to Exmouth here, and different sorts of casts in the Kimberley region of Western Australia.

I'm going to focus a little bit on some work, the pioneering work that Bill started doing more than 20 years ago in the Cape Range region of Western Australia which was a really unexplored area when it came to cast animals. But there are various interested amateurs I guess, but specialists in their own ways in being able to get into these deep caves - you often have to abseil to get into them - and starting to bring back reports to Bill and us at the museum, of all sorts of odd fauna that was living in the cave.

This is the satellite image of North West Cape sticking out of the west coast of Western Australia, and at the bottom of these caves are all sorts of wonderfully adapted subterranean animals. This is an endemic genus of millipedes called Stygiochiropus which only lives in the bottom of these caves. Compared to regular millipedes up on the surface. They're very, very pale and have got very, very long legs, very long antennae, and they also are completely blind.

There are also blind and cave adapted crickets that live in these caves. This is an example of one here. There are very, very unusual cockroaches. You might not recognise this as a cockroach, but a very specialised group of cockroaches that live in subterranean environments in the western half of the country. Once again, long legs, long antennae. These are one of my favourite animals. These are a type of arachnid called a Schizomid. These small things scuttle around. They look like a cross between like a cricket and a spider, but they're actually arachnids. They've got a long pair of first legs that they don't use to walk on. They actually use them as antennae. A big pair of pedipalps that they use to help grasp their prey. They're wandering around in the bottom of these caves as well. Small plant feeding insects - plant hoppers which feed on - they've got sucking mouth parts like all Hemiptera, like all bugs do, and they feed on the sap that's in the root systems of plants that might come down through into the cave environment. You need to go through and look at the fibrous matting of the roots on the plants to be able to find these little blind plant hoppers.

There are also really unusual crustaceans. This is an example of a really unusual isopod that was found up in the Kimberley some time ago. Once again, very, very long legs. Very, very pale. Great big raptorial or grasping front legs used to catch their prey, swimming underground.

Probably one of the most exciting discoveries that's been made by Bill and his team over the years, has been a huge suite of different species of diving beetles in the arid zone in Australia, in Western Australia in particular, or also going over into parts of Northern Territory and South Australia.

These are all photographed at the same scale, and these are all different species. So far, Bill's group has uncovered about 100 new species of these blind diving beetles, and each calcrete aquifer that we were talking about before - because these are discontinuous aquifers that are spatially sort of distributed across the landscape - each different aquifer's got its own species, or sometimes more than one species of these diving beetles. And sometimes when you do get more than one species in a single aquifer, you'll get a big one, a medium sized one, and a small one. So they might be petitioning themselves to take different sized prey. We're not sure. But this discovery is truly remarkable and totally unprecedented anywhere in the world, with this large diversity of these really bizarre diving beetles.

There are also several blind fish. In fact, the only blind fish in Australia occur in Western Australia. This is the blind gudgeon that occurs up at Cape Range and other areas. You can see here it's a pretty unusual looking fish. You can start to see some of the internal organs inside. There are no eyes for example. And there are also blind eels living in some of these habitats as well. These are terribly rare. We don't see them very often, and they're only found in still a few locations. These have likely evolved from eels that occur in regular surface environments or in coastal areas of the Indo-Pacific region along our coastline.

Here's a close-up shot of the head. You can see it's not particularly attractive, okay. It's not something you want to take home and show mum. No eyes. It's got this pink pale colouration. Really odd looking animals.

Now, it's not easy going out looking for some of these animals and the whole theme of this 'In the Wild West' lecture series this time round has been collections, and you can't get collections without going out and collecting.

Bill does a large amount of field work every year, going to remote places, and it all starts with a four wheel drive, and the museum's trailer with all of the camping equipment and gear that Bill might need to get out there and sample some of these environments. So that's actually out the front of his house, all laden up, ready to go. And that's the view as Bill drives along these long, dusty roads, getting out to the landscapes.

It's hard to believe that these flat, wonderfully flat, wonderfully interesting landscapes in Western Australia, have got this teaming subterranean biodiversity underneath them. But that's what Bill's found so far.

There are some hazards on the way - kangaroos, emus on the road, cars broken down. Occasionally, he can't get through because there's been flooding. This is one of the big bridges crossing the Fortescue River up in the Pilbara. That stopped him in his tracks for a little while until the river levels went down.

And this is an example of the dissected landscape that you might see in somewhere like Cape Range, where the millions of years of rainfall and rivers and streams and things running through this limestone, which is relatively soft, gets eroded away so that it forms these big valleys. It makes it very, very hard to get through and find all of the caves in these areas. It means that the cavers who have discovered a lot of these caves have to do a huge amount of walking in terribly rough terrain. It looks to me like it's a job for a helicopter, but they're a little bit too expensive for the museum's budget.

So this is a typical campsite out on one of these field trips. The trailer pops out into a tent for cooking and a little makeshift laboratory. This looks like early one morning when people are just waking up after a freezing cold night in the Yilgarn or the Pilbara somewhere, and yes, mornings are very cold for those of you who've been out there. It can get pretty brisk.

But of course, some of the most interesting environments that we have in Western Australia, certainly in terms of show - well not show caves, but caves that are really pretty to look at, include these sorts of ones where you get lots of stalactites and stalagmites. You can walk or crawl into a lot of them, and the way we find the animals is just to look around under the rocks on the edges of these caves and see what's walking around.

Sometimes these entrances are quite small and difficult to get into and out of. Sometimes they have quite moist entrances with lots of moisture around. The previous one looks like a pretty dry, dusty cave. This one here has got a lot of moisture associated with it - ferns growing at the entrance which is evidence of certainly a lot of moisture.

Safety gear is required all the time. So, helmets and lights, and as I said before, if it wasn't for the efforts of a lot of the caving fraternity, people out there, amateurs out there in their own spare time, getting out finding these caves, then these wonderful environments, might never have been found. These are some colleagues that Bill's been out with, I guess, in the past. I don't exactly know who these people are, but I'm sure they've helped him out on his field trips.

This is someone getting out of a really tight cave entrance up at Cape Range. I actually did that myself on that same trip. I was on that trip. That was well over 20 years ago. I remember crawling out of a hole about that size. It was probably a little bit thinner because it was so tight that I was actually - the limestone's quite sharp and I was actually scratching my chest on the way out and my arms, and I was sort of doing this, and somebody was standing at the top sort of watching me. He'd already come out, and I managed to get myself out and I got all these scratches down my chest and my legs. I got out and said "Whoa, gee, that was a bit tight," and he said "Yeah, yeah. Everybody else came out of that hole which is a lot bigger actually." So I thought "Great. Thanks for that." I've actually never forgotten that.

As I mentioned before, this is how we find a lot of the animals. Even though down in the cave it's pitch black. I mean you literally, if you turn the lights off, you can't see a finger in front of your nose, but using a head torch and looking underneath the rocks, you can find these little animals. Sometimes when we went down into some of the caves in Cape Range when I was there a while ago, abseiled down into a cave, I turned the lights on, all of these things are just walking around on the mud and on the sides of the walls of the cave. After about 15/20 minutes, half an hour, they start to work out that something's wrong. There's light which they've never, ever seen before in their lives, and they just scurry away into crevices or under rocks, and that's where we find them again. So these are more examples of some of these vertical caves that Bill's sampled in. Abseiling into some of these vertical caves is necessary and something that's a little bit dangerous. Certainly the trip I went on, we had to rely on our caving colleagues to get us in and get us out or else we would have been stuck there forever.

And some of the drops into the caves are really spectacular. I actually remember one where it was a tiny little hole at the surface, and we came down, and my headlamp actually wasn't strong enough to illuminate the walls of the cavern. It was just so big. It was like dropping down into a cathedral. Absolutely beautiful.

But, what you found at the bottom of these caves was just remarkable. We found a new genus of quite large spiders. These spiders don't really have a common name. It's once again one of these new species of Troglobites - long legs, no eyes. The surface relatives of these spiders have got eyes at the front of the carapace here, and it was named a few years ago by a colleague of ours who specialised in this particular group of spiders. It was named Bengalla bertmaini, and it was named after the late Bert Main, for his pioneering efforts in promoting the study and conservation of Australian - in particular, Western Australian animals including invertebrates. So it was great that it was named for Bert, which he really enjoyed.

There are other ways of sampling these subterranean environments. So we've just talked about situations where you can abseil or walk or crawl into a cave space. And I mentioned before about these spaces that seem to be very abundant, and in many different parts of, not just Western Australia, but other parts of Australia as well. These seem to be very, very small voids, sometimes may be hairline fractures, sometimes as big as a basketball, or sometimes even bigger. But they don't have openings to the surface. And the way this fauna has been discovered over the last 15 or so years by Bill and his colleagues, has been through examining boreholes that have been drilled by exploration mining companies.

So if you've travelled in the outback, especially in the Yilgarn and the Pilbara around about now, you'll find these funny little clumps of soil that have been laid out by geologists. These are the remnants of the plug that comes out when they drill the hole. They actually pull stuff up and they take samples of it, and the idea is to work out whether it's got heaps of goodies in it like iron ore or gold or whatever they're looking for, and they lay them out like this. If you then get access to the bore hole, you can actually do some sampling and find some subterranean animals.

So this is an example of a bore hole that Bill has got access to. So he found out where it was located. Sometimes they've been covered up again. So you've got to dig them out. Sometimes they're standing proud of the soil and you can just go straight up to them. They've got caps on them to stop things inadvertently falling down them. They actually come up, high like this out of the ground, also to stop things falling ground. So if they're not capped or they don't have this sleeve on them, then you often find that small things like lizards and small mammals and insects and spiders and things, drop down and die down there. But often they're capped nowadays and they're pretty easy to find when they look like that.

What Bill has here, he's developed a little technique where you drop a small container of sterilised dry leaf litter, so from the surface - eucalypt litter or something - which is in a little mesh bag inside one of these sleeves. You tie it on a piece of fishing line and drop it down, right down into the hole, leave it for several months, come back, pick it up later, and you find that it's colonised by the things that are living underground. So the little spiders and the cockroaches and things will all move in to this wonderful habitat because especially for the animals that are feeding on - like to feed on leaf litter, they think it's absolutely wonderful. So they move in. The predators follow them. You can go back a few months later, pick up the sample, place it in a plastic bag, keep it cool, bring it back to the museum and then pop it in these contraptions called Tullgren funnels. So this is a light source up here. The litter is placed in a sleeve in here, with a little funnel down the bottom, and there's a collecting tray down the bottom full of alcohol. So the light actually forces the little animals down through the litter, the light and the heat, down through the funnel. They drop into the alcohol and then you've got your sample. It's a lot more - it's a lot easier than sitting there and picking through the leaf litter trying to pick the little animals out. So once you have those samples, then we can start doing some research on them.

So these are some examples of different sorts of organisms that have been found using some of these techniques. This is a Pseudoscorpion. This is one of the groups of animals that I actually specialise in and this in fact, turns out - this is a species that I named a few years ago called Indohya damocles. I called it damocles because it was only found in one cave that seemed to be threatened by the expansion of the ex-Perth mine site and for those of you who might recall the tail of Damocles, he had a sword hanging over his neck and as it dropped lower and lower, he was at risk of being killed by this sword. So, a little bit of poetic licence you can run with if you can find a new species and you're allowed to think up a name for it.

So also there's large numbers of these slaters - we talked about them before - living in underground environments. This is a good example of a really subterranean adapted slater with no eyes, once again very, very pale colouration.

We seem to be back to accessing - that's right. This is a technique where we talked before about collecting leaf litter and you're finding Troglofauna. So the air breathing component of the subterranean environment. These techniques here are very, very similar. But here it's sampling the things that are living in the groundwater, so the Stygofauna. The way that can be done is finding these boreholes once again, or finding and getting access to wells that have been sunk all over the pastoral zone and elsewhere. There's another one there and it looks as though they're taking measurements of water chemistry, so taking pH and things like that so get an understanding - and salinity - getting an understanding of what the environment is that these animals are living in.

What do we have here? Here's another one here. It's a big bore hole. I'm not sure what that is. That's on Barrow Island. That's one of the oil heads on Barrow Island, the donkey things that go up and down, I think. You must be able to get access to the subterranean environment down there. And in fact, there are a whole series of these bores all over the suburban zone as well. So the Water Corporation actually use these to monitor groundwater which gives us a lot of our drinking water here in Perth, and this is an example of one that's been tapped and the Water Corporation are doing studies on the water that come out of them.

Now Bill's designed these sampling nets which have long mesh gauzes on them and a collecting tube down the bottom, and they, once again, are tied to fishing line and dropping down the holes with weighted sinkers on them, so they drop right down to the water table. You just lift them up and down through the water once you know that you're in it, and pull it back up, and this is the catch you can find. So this particular sample here has got a lot of these little diving beetles swimming around in it. This is an example of one of the ones that came out of that. You can take that tube off, put them into a collecting preservative, and bring them back to the museum for further study.

Some of the really unusual things that have turned up, apart from all the blind animals we've just been talking about, has also been a new species of blind fish. A blind gudgeon that was found on Barrow Island. It was actually very, very small. Not much could be done about it in terms of morphology because that's often how we tell different species apart. But you can use techniques like computer X-ray tomography where you can take scans of these things. This is a scan that was done with Peter Austin at the CSIRO here in Perth, looking at the skeleton of these things. You can do things like then counting the number of vertebrae for example, and finding out whether that's significant in the evolution of these groups.

Occasionally, these blind eels I was talking about before, might come up. This is an example of a blind eel that came out of a groundwater ecosystem on Barrow Island a few years ago. It was actually blasted out when they were doing some blasting to drill a new well. The guys on the island, the blaster didn't know what it was, took a photograph of it, popped it back down the hole even though it was dead, and we're all kind of silently weeping because it's the first record of blind eels from Barrow Island, and it would have scientifically phenomenally interesting, but we didn't get the specimen, so they're down there somewhere. We just haven't seen them again yet.

But there's also another habitat and another technique that is used to sample this subterranean environment, and this is sampling what's known as the hyporheic zone. So hyporheic zones are quite common around the world and mostly you find them in gravels next to rivers and stream beds. This is sampling next to that, that same bridge on the Fortescue River that was in flood that we showed you earlier in this presentation.

What you can do with this type of sampling - there's the flooding that we mentioned before. So this is a gravel bank of a dry river system where you also find this hyporheic fauna. What you can do is actually drive a pipe down into the gravels and the rocky substrate of a dry gravel stream or next to it like the Fortescue River before, until you get down to the groundwater. Sometimes that doesn't take very much. It might only be tens of centimetres underneath the surface, sometimes metres. Drive it down. Attach a pump, a little hand pump to this system, pump the water out into a bucket and a sieve, and then after a little while if there are fauna down there, you can start to pump out into a sieve, different sorts of animals that can be studied. We're finding different types of animals here that you would find in something like a calcrete system which would be in these paleo river drainage basins.

So often down here there's much smaller animals like water mites and ostracods and copepods, but a very interesting fauna, and often very modified to live in these small, what we call 'interstitial spaces' in between, underneath, and next to river banks. So wonderful, very specialised fauna.

So this is an example of Bill and his crew out sampling in the outback. Often you can set up a field laboratory and actually sort these things while you're sitting there. So this is a microscope on top of an alley bin set up that's a bit all rough and ready, but it works. And these are the examples of some of the things that might come out. So these are some subterranean arthropod crustaceans. Once again, you can see very, very pale in colouration, absolutely no eyes whatsoever.

This is an unusual group of crustaceans where, this is an example of a female that actually broods her eggs and possibly the young in sort of a pouchy area on the underside of her body. But this is a totally different groups of crustaceans altogether. So these are called Halosbaena is the genus. The Thermosbaenacea - I can't say this word very well - and they're only found in a few places in the world. The Caribbean and the Canary Islands are two of them, and here up in the Pilbara and North West Cape area of Western Australia. They're evidence of a very, very old fauna that's persisted in a couple of parts of the world for a very long time, and this region in Western Australia is very special because of that.

So Bill also sometimes tries to get funding or get mining companies to actually put in bores, getting drillers to actually put them in. It's a pretty expensive operation to get some of these guys out for a couple of days to drill one of these things, but Bill's been able to get funding to drill boreholes up at Bunderra Well which is a very odd ecological system up near Cape Range and North West Cape, and in fact he told me this morning that this image here is less than a couple of weeks old, comes from Bunderra Well up near Cape Range as I mentioned, and it's a totally new type of crustacean that hasn't been seen in that area of Western Australia before. He's not sure what it is, but he's pretty excited and looking forward to starting to study it and see what it might be.

This is Bunderra Well - Bunderra sinkhole itself. It's what we call an anchialine system. It occasionally becomes eutrophic on the surface; you can see all this algae and stuff floating on the top. But once again, Bill has great assistance from volunteers in the study of this system because the only way you can really study it is to dive inside the sinkhole. It's quite deep. So this is one of the volunteer specialist cave divers. It's not something I'd like to do. It's dark and pretty spooky down there. This is the guys going in. Very specialised apparatus, rebreathing apparatus so they don't form those bubbles that come out of a regular aqualung system, because the bubbles would upset the chemically-stratified layers which I'll show you in a couple of slides.

So it's quite murky when you get down there. These are the guys heading off down into one of the areas here to take samples for Bill, and at the interface of freshish water at the top and saline water at the bottom, you get this milky film which is very sulphur laden, and that helps drive the whole system of Bunderra Sinkhole. I'm sure Bill could explain that a lot better than I've just done, but it's a pretty unique ecosystem, one of, I think the only place in Australia that's actually like this.

This is a photograph taken by one of these cave divers - Stefan Eberhard - of one of these blind gudgeons we mentioned before, in Bunderra Sinkhole. You can see the photograph taken of this tiny little fish.

This is the rebreathing apparatus that the guys use to make sure that those bubbles don't upset the chemical balance inside, and the sinkhole itself is full of all sorts of really unusual crustaceans. So this is a really weird animal called a thermosbaenacean - no, that's not true. Hang on. It's a remiped. Yeah, thanks. I nearly got something wrong. Actually, I've got a lot wrong, but that was the only one that's obviously wrong, right? So, so far. So this a remiped, a really primitive crustacean, possibly something like the ancestor to a lot of other crustaceans that lives there. It's the only species in Australia. The others are all found in disparate parts of the world - Canary Islands once again, and in the Caribbean. And there's also these funny little ostracods called Danielopolina which also are found in Central America, the Caribbean and in the Canary Islands, and on Christmas Island, and at Bunderra Sinkhole. And it looks as though the species - this is a molecular tree that Bill and his colleagues have managed to develop which is overlain on their distribution, and you can see looking at the phylogeny of this group of animals, that the Australian and Christmas Island ones are very archaic, and not unlike - and totally dissimilar in fact, to the ones found off the coast of Africa and North America. In fact, I'm pretty certain that there are fossils of these things dating back a long time in the fossil record as well. So these are truly unusual ostracods and only occurring in one place on mainland Australia.

Bill tried to explain to me the significance of this image this morning over the telephone. He did an admirable job, but I'm not quite up to it. I think what he was trying to tell me is that this is a technique where you can actually take a sample of water out of something like Bunderra Sinkhole - this is from Bunderra - you can actually run really specialised genetic methodologies through. IT's called 'Next Generation Sequencing'. You can dump the results of that into a computer program which will then generate a phylogenetic tree telling you how distinctive these animals are. And, the significance of it is that apart from regular things coming out there, like there's remains of mammals, you don't need much to get a genetic signal out of this water. Even something that's peed in the water is enough to be able to work out that something was there. There's all sorts of things in there including crustaceans and insects and mammals, goats and things that have dropped in. But there's lots of what we call these extremophile lineages of sulphurous bacteria. So, Bill suggested that these are like living laboratories for habitats that are difficult to access, including such as under the deep sea and under ice. In fact, there's a lot of work that's going on in Antarctica studying these extremophile organisms in places like Antarctica, seeing what life might have been like when life first evolved 4 billion years ago. So these organisms are still alive today. People troop off to odd parts of the world to try and study them, but we've got a living habitat, a natural laboratory up at Bunderra Sinkhole that might serve to be a really good example of how you can study these types of evolutionary processes.

This is one of the vent systems where the continental plates collide with each other - the deep sea vents - where you also find lots of these different types of extremophile bacteria and other organisms, so things living at the edge of existence and relying on sulphur, rather than carbon, for their primary energy source. There's a lot of research going onto what's happening coming out of these deep sea vents. And that's an image of, I guess the moon, or the earth may be, when it was formed many millions years ago. This is Bill's final slide. Why travel to the planets and the moon when we've got wonderful living ecosystems here on Earth, especially in Western Australia, we can study and we need to study right now to understand what's going on. That's my final slide. I'm really happy to answer questions as best I can. Thank you very much for your patience and I'm really sorry that Bill's not here to give this presentation.

Thank you.

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