Thursday, September 24, 2020

The freedom of the press still furnishes that check upon government which no constitution has ever been able to provide – Chicago Tribune.

Home Issue 32 A touch of light: deep water, dry river

A touch of light: deep water, dry river

By MIKE GILLAM

All images © Mike Gillam

I arrived in the predawn, a crescent moon and Venus standing brightly to the north, above and beyond the ramparts of the gorge. I made out the silhouettes of small bats, returning to their roosts in rocky clefts and red gum hollows, the most numerous mammals in this landscape.

I was in Udepata (‘oo-DEP-pa-tuh’) in the language of the Western Aranda, referred to as Ellery Creek Big Hole or Ellery Gorge by white settlers, a much-visited site in the Tjoritja/West MacDonnell Ranges National Park.

The strongly defined negative space framed by opposing walls looked vaguely familiar, the outline of a geographical landmass I should know. A map of the Lake Eyre Basin? Day dreaming is a necessary part of wildlife photography.

This is my modus operandi for excursions to permanent pools in Centralia. Sit well out of the way, as silent as a rock and enjoy the natural ebb and flow of the place. Use the telephoto lens to spy out the terrain. Watch and learn, be patient, prepared and above all anticipate. Wait for something to happen, all day if necessary and then the next.

My upbringing dictates that I always go bush with an informed plan, a solid, deeply considered reason for making the effort. More than often the subject of interest fails to comply with my plan and I return with nothing or something completely different, maybe even better than I could have imagined.

The day before I’d sat for several hours overlooking a pool in the Hugh River. Restless dragonflies in red, blue and green patrolled the shallows testing my reflexes. A group of perhaps twenty spangled perch, the most successful of Larapinta (Finke River) fish, were visible in the deep central channel, also waiting.

Then a grasshopper for reasons unknown took a crazy misjudged jump and landed in the shallows below my position. I moved quickly down the embankment, focussed a tele lens on the stationary grasshopper and waited. It took the fish a minute to find the wayward insect which quickly discovered how to walk on water and leapt to safety. The fish looked disgruntled, their normal demeanour, but I got an interesting image for my patience.

Propped against a tree at Udepata, my eyes drifted firstly around the ramparts and then looped back following the lower margins of the deep pool. Viewed through the brevity of human experience, the rocks are resolute and timeless, but I noticed some changes to the waterhole since my last visit in the height of summer.

Then the place had been packed with clusters of people sitting/lying on beach towels or standing neck deep in the dark water doing I’m not sure what, maybe just cooling down. Some of the young ones were promenading on the narrow sand spit, admiring one another’s selfies.

On the eastern bank the exposed roots of Eucalypts were extended in reflection, a palisade of ceremonial poles, plunging to drink deeply in the shadowy depths. These were joined by meandering Ficus roots that stretched down from a glossy green fig clinging to a damp crevice.

Close by a group of young men, unashamedly distracted by the sand-spit catwalk, were attempting to navigate around the treacherous rocks that form a barrier to the northern shore. I could tell them from experience that swimming, while dangerous in the cold pool reputedly 27 metres deep when full, is easier. A flotation aid is highly recommended especially in winter and mandatory if you’re carrying a camera.

 Now it was a sanctuary, devoid of chattering humans and I was held in the thrall of birdsong. The finger of sand that creates a popular peninsular for birds (before and after its occupation by sun-worshipping humans) had grown substantially in bulk, a testimony of many months without rain. As Venus glided from view, the restless wind waited to make its entrance.

Faint south-easterly gusts disturbed the slumbering waterhole as I watched. The breeze was low angled and not strong or constant enough to set up the rhythmic flow of ripples to crash against the downwind shore. More a frenzied play of wind and light, of photon scintillas coming in bursts, sparks and showers.

As the sun rose higher the dynamic streaks and catch-lights increased in intensity; water sprites were everywhere skating and playing across the dark satin sheet. The effect in that early light was starkly monochromatic, black water with bright highlights slowly acquiring more and more colour as the sun climbed.

At midmorning dramatic reflections of the lower cliffs and river bank vegetation appeared in lively reds and muted greens. A pair of Australasian grebes paddle-glided effortlessly across the waterhole enjoying the sun and painting as they went (see at top). In their wake angled planes of water reflected the impossible blue of a desert sky. Now the wind rendered the surface of the waterhole with the texture of a palette knife painting and then it was gone.

A curious crow caught my attention in the Eucalypt above my head. He’d found a python, Morelia bredli, its 1.5 metre length casually folded over a platform of branches, the red, black and yellow patterned tail anchored more firmly in a knot. The snake was enjoying the dappled light and hoping for a curious honeyeater to come too close but crow was definitely not on the menu. The snake is far too big for this perpetually hungry crow and the bird is too big for the snake to swallow so it was a stalemate and the crow, his gimlet-eyed prowess confirmed, moved on.

Distracted by the snake I missed a spectacular flyover of eight pacific herons but they returned later and settled on the west wall of the gorge, their presence in this dry year a clear sign of Udepata’s productivity.

This body of water, protected by buttresses of terraced rock, oxide hues varnished by the resins of plants, does not suit all waterbirds. Most are discouraged by the close proximity of humans who don’t understand the basic rules of sharing and are inclined to assert their inalienable rights to have fun and remain comfortably ignorant of the costs. I suspect they cause more stress to wildlife than the peregrine falcons. Less claustrophobic, the open lagoons of water along the Finke River, such as Two Mile and Boggy Hole, are the preferred habitat for cormorants, pelicans and spoonbills.

I wonder how the resident herons manage disturbance and predation at Udepata. They are a family group of course and the young will probably disperse in due course.

Later as they sunned themselves on the western side of the gorge I managed to take an image with seven of the eight in the frame (above). I suppose if life gets intolerable the herons can always fly to Boggy Hole about 30 kms downstream and try their luck.

South of Boggy Hole, (I really need to find the Western Aranda name which will likely prove more poetic than ‘hole’), I once watched a peregrine falcon swoop low over a boomerang shaped lagoon, sending a mixed flock of panicked cormorants and ducks into the air. The falcon casually wheeled about, selected its target and hit a cormorant, a blow too fast to describe. The cormorant fell like a stone and I’m certain it was dead before it hit the ground. I ran, rolled and crawled over a low sand bar and there was the falcon standing astride the cormorant in deep and photographically unworkable shade.

Enough day dreaming. At Udepata the first tourists arrived after a leisurely breakfast, coffee cups still in hand. By midmorning the best sitting spots on the banks of the pool had been claimed. Most had eyes only for each other and wouldn’t see the snake in the canopy above. Stories of four wheel driving adventures were shared, road conditions and equipment were compared, free campgrounds and helpful mechanics reported in loving detail. They were mostly city folk and I realised with a jolt how lonely they seemed, how much they craved the company of strangers. I was approached by numerous people who wanted to chat about the length of my lens, others who asked for photographic tips or help driving their cameras.

There are a great many images online that speak to Udepata’s popularity with tourists, overwhelmingly of people looking for a spa pool. I just wish swimmers could avoid sunscreens. If the latest swimsuit fashion and courtship promenading is the aim, perhaps they could accept some collateral skin damage in the interests of frog health. Better still wear a long sleeved shirt and hat to avoid the surface slick that I once observed on the surface of the main pool. 

The lens of surface water at Udepata is finite, rarely refreshed by inflows, and critical to the wildlife that inhabits this special place. Protecting this valuable resource and sacred landscape needs lifting beyond the apologetics of fine print and the imperatives of mass tourism. What is the ‘sustainable’ carrying capacity of this place? Everyone’s looking for peace and tranquility, unfortunately everyone is often too many, a great impediment to this ideal.

With appropriate action and care, a bright future for the freshwater ecology of Centralia  actually seems possible. According to Davis (1997) “…The lack of large numbers of introduced species of fish in central Australian water bodies suggests that the composition of fish communities in this region may be largely unchanged since European settlement…”

In her paper Davis also highlights the serious impacts of nutrient enrichment at natural water points caused by the watering of livestock, the over-pumping of local aquifers, for example to support tourism infrastructure, and the translocation of the introduced yabby, Cherax destructor, as serious and potential threats to our fragile and fascinating aquatic realm.

In a low rainfall region with high rates of evaporation, a knowledge of water, how it flows across the landscape, where it settles and where it persists is essential. The deepest and most permanent pools are usually located on drainages such as Larapinta (Finke River), the Hugh and Ellery, frequently where rivers and creeks cut through rocky ranges.

Upland catchments in the MacDonnell and Chewings Ranges harvest and direct rainfall into gullies, crevices and minor creeks that flow downstream into larger creeks and rivers. Along the way small (often tiny) lenses of water are held in rock-holes situated in deep crevices where low rates of evaporation and a degree of permanence creates rich micro habitats. High above the major rivers these special places support unusual aquatic communities quite unlike those inhabiting the major riverine environments.

During significant rainfall events these upland rock-holes and rare relictual stream environments overflow and water enters the dry bed of major creeks and rivers. Here large volumes of floodwater may abruptly vanish as a depleted water-table slowly refills. Only when the thirsty sand is quenched, will the desert river flow in ways that satisfies human expectations of what makes a true river.

Where underlying geology is favourable the downstream flow of water is trapped in localised aquifers, frequently situated between rocky benches in shady gorges that help to mitigate high rates of summer evaporation. These larger waterholes are a key resource for mobile species such as birds and bats but even more critical for resident aquatic vertebrate and invertebrate species which in turn sustain a suite of predators and detritivores.

Large permanent pools are important refugia for fish; a surprisingly rich community of nine native species occurs in Larapinta (Finke River) alone. In times of flood, the waters of Kartatuma (Ormiston Gorge) and Udepata (Ellery Bighole) meet in the major desert drainage that is Larapinta (Finke River) and the core populations of fish are finally free to mingle, breed prolifically and disperse widely.

Many years ago I photographed the mountain catchment following a fast moving storm. The rain had cleaned much of the dust haze from the air and the ground was beautifully saturated. I hired a helicopter and photographed the catchment looking north with the broad sandy sweep of Larapinta passing through the range at Glen Helen Gorge (above). The low cumulous parted and moved through just in time.

From an average elevation of 750 metres in the catchment, the ancestral Larapinta once flowed south east to the Macumba and ultimately Kati Thanda (Lake Eyre) which lies 15 metres below sea level, the lowest point in Australia. At its vague terminus on the western edge of the Simpson Desert, a drier climate and evaporation now claims Centralia’s greatest river in a variegated landscape of coolabah floodouts and ephemeral wetlands.

In a similar palaeo environment I watched botanist Peter Latz excavate sediment surrounding a coolabah tree to a depth of over a metre to demonstrate the significance of upstream erosion in the past century.

So too the final sections of Larapinta have been gradually altered, a combination of silt deposition, shifting sands and the lack of epic flows to keep channels open. Unheralded flooding and inundation across this landscape that now lacks an organised drainage would be required to re-connect Larapinta across a distance of 640 kms, with Kati Thanda. 

Notes: “…Sunscreen ingredients have been shown to damage coral, accumulate in fish and the environment, and disrupt hormones in fish and amphibians…” (Buser 2006, Danovaro 2008, Giokas 2007, Kunz 2004, Kunz 2006, Weisbrod 2007).

“…The Fleay’s Barred Frog are one example of a frog species threatened almost to extinction attributed to sunscreen and insect repellent…” https://www.bushwalkingnsw.org.au/frogs-and-sunscreen/

3 COMMENTS

  1. Wonderful, words cannot express what I feel. No need to leave the Territory to go on holidays anywhere else.

  2. OK Mike, I eventually found the neck and head of the sixth heron on the far left, but I can’t find the seventh. Or are you just keeping us on our toes?
    Also I recall research dating flows of Lhere Pirnte to Kati Thanda 700 and 1200 years ago.
    Just the blink of an eye really. The next one could be this summer.

  3. You’re right Charlie, in the rush to post the essay I cropped the 7th bird off the bottom of the image.
    I admit it was tempting to exchange the images on line and mess with your head but the corrections policy of the Alice Sprigs News is very strict!

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