‘Plane Tales From The Hills

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I usually write a post and then struggle to find a suitable title. This time, reading Rudyard Kipling on a flight to India, the title came first and all I need to do was find words to fit it. The honest truth is that an event-free flight is the best kind of flight, and BA257 was just that. My highlight on long-haul flights is usually catching up on films that I have missed; this time I whetted the appetite for travel with Werner Herzog’s Queen of the Desert, a biopic about Gertrude Bell. I should claim her as a local hero (the Bell family once owned the pit in my village) except that her contribution to dividing up the Middle East in the aftermath of the First World War unwittingly helped to precipitate the current mess. But, hey, who needs historical accuracy when you have Nicole Kidman looking ice-cool and elegant amidst the desert heat? (Tony Blair is a local lad, too, so there must be something about the north east that makes its children completely unsuited to  Middle Eastern geopolitics …)

That’s “Plane Tales” explained. Sort of. Now for “From The Hills”. I’m writing this from Clarke’s Hotel, a venerable relic of the Raj in the former hill station of Shimla. I first visited Shimla (or “Simla”, as it was known in Kipling’s day) over 30 years ago. This time, I am back, meeting up with Heather as she reconnoiters another route for Indus Experience. She’s been here for three weeks already and whilst I soak up the exotic ambience, she marvels at such modern contrivances as the hot bath and cold beer.

Half a day in the heat of Delhi’s strength-sapping heat is enough to make you realise why the colonial administration decamped to the foothills of the Himalayas during the hottest period of the year. We (myself and Helen, a fellow “plus one”) followed in their footsteps, catching a train from Delhi to Kalka, and then transferring to a narrow gauge train for the final five hours to Shimla. I first read about this in Paul Theroux’s The Great Railway Bazaar, which inspired me to add this to my itinerary on my first trip to India. Kalka is just at the edge of the Indian plain, and the train starts a long, slow climb almost as soon as it leaves the station, negotiating tight curves and over a hundred tunnels as it makes its way to Shimla. In the early stages it moves through dense broad-leaved woodland, but these gradually give way to pine forests as the train climbs and, as it approaches Shimla, the pines are interspersed with Deodar cedar trees too. An ironic whoop of delight greeted our first sight of Himalayan Balsam in its natural habitat.

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The “toy train” making its way from Kalka to Shimla, August 2016. The top photograph shows a view of the Himalayan foothills from the train.

Shimla is a glorious, if slightly rundown, anachronism, with buildings evoking the Home Counties side-by-side with modern India. It is not difficult to imagine the mock-Tudor architecture as a backdrop to the shenanigans between colonial service wives and dashing subalterns that Kipling wrote about in Plain Tales From The Hills. The short walk between the Gothic Revival-style Christ Church, at one end of The Mall, the central thoroughfare, and Jakhu Temple, dedicated to the Hindu god Hanuman sets this contrast into perspective. “East is East”, wrote Kipling, “and West is West, and never the twain shall meet.” Shimla, in his time, would have encapsulated that, and some of his short stories touch on the complications that arose when love crossed the cultural and racial divides. In modern Shimla, the East has gradually reasserted itself. We are looking at the reciprocal of “Orientalism”: a mock Tudor building here having the same jolting effect as, maybe, Brighton Pavillon has to a British observer.

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Christ Church and the town library in the centre of Shimla. The statue of Hanuman can be seen just to the left of the church tower.

Life is, of course, rarely that simple. The day before we travelled to Shimla we had visited the tomb of Humayun, the second Moghul emperor, in Delhi. To western eyes, this elegant building, a precursor of the Taj Mahal, fits all of our preconceptions of what an Indian building should look like. But the Moghuls, too, were interlopers, bringing Persian ideas and culture into the sub-continent a couple of centuries before the British arrived. In my travels around the Hindu heartlands of northern India I have seen almost no vernacular architecture that resembled, in any way, these Moghul edifices.  Despite being the quintessence of what we think of as “Indian”, they are no more or less “authentic” than Shimla’s mock Tudor architecture. The difference is that we have enough cues to make the connections at Shimla, but not for the earlier waves of invaders.

Arriving at Persia via Delhi and Shimla does, at least, bring us to the land where Gertrude Bell, feisty north east lass, whatever Werner Herzog and Nicole Kidman would have us believe, made her first explorations. That closes the circle and, as much by luck than judgement, justifies the title of my blog. Which was, you have to admit, too good to waste …

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Humayun’s tomb in Delhi, August 2016.

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Abstracting from reality …

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In a recent post, I mused on the blurred boundaries between “representation” and “abstraction” when applied to the microscopic world (see “How to win the Hilda Canter-Lund competition (2)”.  These reflections sent me back to one of our earliest winners, Mario Sironi’s image of a Southern Right Whale swimming through an algal bloom (see “How to win the Hilda Canter-Lund competition”), to test these thoughts.  My reflections were mostly concerned with the microscopic world; that Mario’s image deals with one of the largest organisms on earth just helps to make the point.  At the heart of representational art lies the ability of an independent viewer to relate a two dimensional image to a “sense impression” (or “schemata”) lodged in their mind.   That means that if the viewer does not have the same schemata as the artist, then an image that was intended by the artist as representational will not be recognised as such.  The artist usually assumes that viewers will possess a catalogue of such schemata that are broadly similar to his or her own.

Most people who depict the natural world – whether by photographs or other media – confine themselves to the macroscopic and the obvious.  This means that there is a strong chance that the viewer will possess the appropriate schemata and both “recognise” the image and make appropriate mental connections that allow viewers to add layers of context in order to interpret a picture.   A picture of a lamb, for example, should be recognisable as a juvenile stage of Ovis aries.  This, in turn, may be used by the artist to suggest an interpretation.  To a 16th or 17th century viewer, a lamb included in a portrait of a child suggests youthful innocence: an interpretation that may be lost on a modern viewer who sees, simply, a child with a lamb, but lacks the mental connections to read more deeply into the image.

When the microscopic world is used as subject matter, the distinctions begin to blur yet further – the images themselves might be “realistic” but still not be recognisable by the lay viewer, and the reduced number of mental connections will limit the ways in which the picture is interpreted yet further.   One person’s “representation” can become someone else’s “abstract” image.   The idea in the painting above is to take an image that is representational – most people would recognise that two whales formed the focal point – and then to “nudge” it over the border into abstraction.   The interplay between the greens and the blues of the water brought to mind some of Mark Rothko’s juxtapositions of colour.   The whales and their attendant foam could, in turn, be reduced to a few lines of black and white paint, providing a focal point for the canvas that sets it apart from Rothko’s signature style.   In retrospect, I could probably push the image a little further towards abstraction than this experiment …

I see antecedents for this work in Piet Mondrian’s explorations of the boundary between realism and abstraction around 1912.  He painted a whole series of images of trees that gradually, over time, were stripped back from recognisable Post-Impressionistic landscapes to a point where form was asserted over content, the palette was reduced and, eventually, the schemata of a “tree” disappeared altogether.

My point is that the boundary between “realism” and “abstraction” is not a fixed point, but depends upon our own sensory experiences.   Those of us who portray the world of microscopic algae need to remember this.  Perhaps the same argument can be posited for the boundary between “representation” and the “other worlds” theme that I mentioned in my earlier posts?   Again, we need to consider our audience: my aim in my paintings and in these posts is to convey some of the wonders of the natural world that most people overlook.   The question we need to ask is whether we are fulfilling this role as ambassadors for the hidden world of algae if most of our audiences are just seeing shapes and patterns?

Reference

Gombrich, E.H. (1960).  Art and Illusion.   A Study in the Psychology of Pictorial Representation.   Phaidon Press, London.

How to make an ecologist #10

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My occasional series of posts looking back over my career had reached Italy just in time for me to ruminate on the problems that would face Britain were it to leave the single market (see “How to make an ecologist #9”).   I did not get so far, in that post, to talk about why we had dragged so much equipment across Europe in the first place.

The project was a European Community (as it then was)-funded project to look at the vegetation history in the period following the last ice age; the standard way to do this is to collect a long core of sediment from the middle of a lake or bog, then to take samples from different depths along this core and examine the types of pollen grains that are present.  Because sediments are laid down sequentially over time, changes in the composition of the pollen as you move from the bottom to the top of the core provides a record of how the plants that were producing pollen in the area had changed over that time.

This was the period when global climate change was beginning to be recognised as a serious problem.   People had worked out that looking at the insights into vegetation in the past that pollen analysis offered could give many clues about climate at the time.   This, in turn, could be used to check the models that were being developed to predict climate change: in effect, if the models can “hindcast” climates that support vegetation known to exist at points in the past, then maybe we will also be able to “forecast” with greater confidence.  The problem was that most of the people doing this work were in the moist temperate parts of Europe and North America, where there are plenty of lakes and bogs from which to core.   Drier parts of the world, such as the Mediterranean Basin, had fewer lakes, a consequence of which was that there were fewer scientists with an interest in these techniques.   This also meant that there were fewer historical benchmarks in this region against which climate models could be tested, and our project set out to fill this gap.

One feature of peninsula Italy is that there are a number of lakes associated with the cones of extinct volcanoes, and this was had already raised the prospect of opportunities to collect cores that would help us understand how vegetation and climate had changed in this reagion.   We travelled first to Monte Vulture (photographed above), in the Basilicata region around the “ankle” of Italy, to collect cores from Lago Grande di Monticchio, one of the two lakes inside the crater of the volcano.   I included a photograph of us coring in the marsh area beside the lake in my previous post on this subject; the 33 m long core that we collected was passed on to Bill Watts at Trinity College Dublin to continue a study of the lake that started a few years earlier.   Subsequent visits by the Durham team and collaborators (after I had moved on) extended this glimpse into the past back to over 100,000 years ago.

The second location that we visited was a small crater lake, Lago di Martignano, just to the north of Rome.  We collected this with help from geologists from Edinburgh University who had a “Mackereth” corer.   This is a contraption that uses compressed air pumped from a boat to first push the corer into the soft sediments and then to slowly extract the core and bring it to the surface. The final stage, when the core is free from the sediment and filled with compressed air, results in a dramatic emergence of the core, cables, floats and other paraphernalia, which leap into the air above the lake surface before crashing back down.   Needless to say, capturing the event on camera is not easy, but everyone tries …

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Using a Mackerth-type corer in Lago di Martignano, Lazio, Italy, September 1988.  The left hand picture shows the buoy marking the spot where the corer has been lowered, and the cables through which compressed air is pumped; the right hand image shows the corer breaking the surface of the lake once the core has been collected.

That core, from Lago di Martignano, was the one that I worked on for the next year, extracting the pollen with a cocktail of strong chemicals.  Our house was burgled during this time and the scene of crime investigator who was investigating to my fingerprints in order to eliminate these from his investigations.  He tried several times before telling me to take up a life of crime as I had no fingerprints and was, therefore, undetectable.  I attributed this to conditions in the rather basic laboratory that we were using at the time to prepare our samples.

Very roughly, the balance between pollen from trees associated with temperate climates, such as deciduous oak and beech, and pollen from the shrubs typical of the hot dry Mediterranean climate (see pictures below) allowed some insights into the climate that prevailed at the time that the sediment was laid down.   In the upper levels of the core, however, we also had to account for the effects of humans, removing trees and planting cereals and, in the process, upsetting the pure climate-driven signal that we were looking for. Unravelling this mix of influences made for an intriguing challenge, and also led to my first serious forays into statistical analyses, performed, in those days, on slow mainframe computers.

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Characteristic “maquis” plants, photographed during fieldwork in Italy during 1988.  Top left: Erica arborea (tree heather); top right: Pistachia lentiscus (pistachio); bottom left: Rosmarinus officinalis (rosemary); bottom right: Paliurus spina-christi (Jerusalem thorn / crown of thorns).

The method only worked, however, if we could “calibrate” our historical records against modern situations where the climate was already known.  The quest for pollen samples from a wide range of climates spilled over into holidays, with a memorable sampling trip during a trip to Jordan in 1989.   We drove into the Syrian desert on a dull, overcast day in search of Azraq Oasis, as sediment from the ponds here would have given us an insight into the pollen we might expect in semi-desert conditions.   There were more than just scientific reasons for wanting to make this trip: there is a 13th century castle at Azraq, built on the site of an earlier Roman fort.  We live close to Hadrian’s Wall and here, at Azraq, we were 4000 kilometres away at the opposite corner of the Roman Empire.  The castle is still largely intact and was, in fact, the headquarters for T.E. Lawrence’s operations against the Ottomans during the First World War, and little had changed since he wrote Seven Pillars of Wisdom.   I seem to recall that another Lawrence – D.H. this time – was cited in an early draft of the paper that arose from this study.   His travel memoir Etruscan Places had some references to the densely-forested landscape that had inhibited Roman soldiers in their forays against the Etrurians.  I thought that this corroborated our results; however, it had disappeared from the manuscript before it was submitted, probably for the best.   By that stage I was in Nigeria and too far away to fight my corner.  But that is jumping ahead …

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Qasr Azraq in the Syrian Desert in Jordan, photographed during our visit in spring 1989; the right hand image shows the Bedu custodian demonstrating the stone doors.

Reference

Kelly M.G. & Huntley B. (1991).   An 11,000-year record of vegetation and environment from Lago di Martignano, Latium, Italy.   Journal of Quaternary Science 6: 209-224.

 

A bigger splash …

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This post continues my occasional series on insignificant black or dark brown spots on submerged stones (see “Both sides now …” for another recent episode).  I found these particular specimens on a cobble in Croasdale Beck in Cumbria, close to my regular haunts around the River Ehen and Ennerdale Water and thought that, with algae grabbing headlines for the wrong reasons yet again, I should write something positive about them.   What kind of weird world do we live in when people think it strange that algae thrive in a warm, well-lit swimming pool, whilst simultaneously lauding other people who devote four years of their lives to practising jumping into that same pool?

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Colonies of Chamaesiphon cf fuscus (mostly 2-3 mm in diameter) growing on a submerged cobble in Croasdale Beck, Cumbria, August 2016. 

There was something about the regularity of the outlines of the dark brown / black spots on some of the more stable stones in this flashy beck that attracted my attention.   I’ve scraped a lot of dark smears and smudges off rocks in the past and often been disappointed when all I find are inorganic iron or manganese deposits.  Over time, one gets an eye for what is and is not an algal growth (or, for that matter, a submerged lichen) and even, in some cases, for the type of alga that formed the growth.   In this case, I had a good idea, straight away, that I was looking at a member of the genus Chamaesiphon, a cyanobacterium (blue-green alga).

Members of this genus are unicellular and form dense mats of cells that can be difficult to photograph.   I could not get a really clear view of individuals within this particular colony so, instead, have included some of Chris Carter’s photographs of another member of the genus.   You can see the short, club-shaped cells, each in a sheath and many topped by small “exospores” which bud off from the mother cell to propagate the colony.   The sheath has a brown tinge, presumably to the “sun-screen” compounds that we have met before in cyanobacteria.   Most of the members of the genus live on submerged rocks, but a few live on other algae (see “More from the River Ehen”).   Most of the rock-dwelling species indicate at least good conditions in rivers, but one species, C. polymorphus, is tolerant of more enriched conditions, which complicates use of a straight genus-level identification for rapid assessments.

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Chamaesiphon polonicus from Caldbeck, Cumbria, photographed by Chris Carter.  Top left: looking down on colony; other images: side views showing cells in their sheaths and, in a few instances, with exospores. 

Oddly (to me at least) press coverage of the Olympic diving pool story has only used the word “algae”, never telling us what sort of alga is responsible for the problem.   This is equivalent to the commentators saying that “animals” have just made a perfect leap off the 3 metre springboard, leaving the audience to work out whether the subsequent splash was made by a slug or a human.

But I should end on a positive note: better, perhaps to compare the algae not with the divers but with the judges who assign the final scores.   That’s because a few minutes mooching around a stream or beside a lake can usually reveal enough from the types of algae that live there to give some insights into the health of the stream.   My visits to Croasdale Beck over the past year or so have shown me enough to suggest that this little Cumbrian stream probably deserves the algal equivalent of an Olympic medal.  But I doubt that we’ll get much press coverage for saying that…

There will be blood …

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Friends from the local Environment Agency office got in touch this week with a query about a red colouration in the water in a pond in a park in North Shields, which they suspected to be an algal growth of some kind.   Their preliminary observations were sufficiently intriguing that I downed tools on Friday afternoon and headed out to take a closer look.

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Two views of the red bloom in Chirton Pond, August 2016 (photos: Tina Flinn)

The photographs show just why passers-by were concerned: large blood-red areas of water, clearly visible from the banks.  There were also, apparently, records of dead fish and ducks although there were ducks and moorhens swimming and feeding, apparently unaffected, by the time of my visit.   A single droplet of this water, viewed under the microscope, was teeming with tiny fast-moving red cells.  However, naming the organism responsible proved to be more problematic.   I started with a short-list of algae that live suspended in lakes and ponds, with one of the most likely candidates being Euglena sanguinea.   I wrote about Euglena last year (see “A visit to Loughrigg Fell”): E. sanguinea has, as the name suggests, a blood-red, rather than green colour, and is very widespread in ponds and other standing water bodies.  However, a very quick look down the microscope ruled this out on two counts: the cells in my sample were too small (rarely longer than 12 micrometres, except cells close to division, as in the illustration below) and they also lacked the characteristic shape-changing cell wall (“pellicle”) of this genus.   Close observation also suggested that these cells were prokaryotic (i.e. lacking any differentiation into internal organelles) rather than eukaryotes.  So it was back to the drawing board …

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Chromatium cf okenii  from Chirton Pond, North Shields, August 2016.   Left: a sample of water from one of the blooms; right: two individual cells.   The arrow points to a flagellum on the upper cell, but note that there is also a very thin Cyanobacterium filament alongside the cell.  Scale bar: 10 micrometres (= 1/100th of a millimetre).

Most of the cells were moving too quickly to allow their details to be seen or photographed clearly, and my photographs were of the small number of sessile cells, each of which had a purplish-red interior, along with a number of refractive inclusions.  I was, in fact, looking not at an alga at all, but at a purple sulphur bacterium, probably of the genus Chromatium.   The purple colour arises from a mixture of bacterial chlorophyll and carotenoids and, despite the similarity in appearance, they do not contain the phycobilin pigments that are characteristic of Cyanobacteria (blue-green algae).  We are, in other words, looking at a completely different evolutionary lineage than anything I’ve written about in this blog previously.

Whereas photosynthesis, as practised by the green plants all around us, uses carbon dioxide and water and produces sugar and oxygen, the purple sulphur bacteria use carbon dioxide and hydrogen sulphide, and they do not produce oxygen.   Instead, they produce sulphur as a waste product and, as this is a potentially-toxic compound, it is “wrapped up” in a protein layer to create the refractive inclusions that I could see inside the cells.  Another feature of the photosynthesis practised by purple sulphur bacteria is that it can only take place in anaerobic conditions and this offers one possible clue to the reports of dead ducks and fish.

I did not take time to look at the sediments at the bottom of Chirton Pond but can take a guess that they are a dark oozy mass, largely composed of the decaying remains of the submerged plants that filled the pond.   The bugs that are slowly digesting this submerged “compost” will suck the oxygen from the sediment faster than replacement oxygen can diffuse in from the overlying water.  This, in turn, will encourage the formation of the hydrogen sulphide that Chromatium needs as its feedstock.   The warm weather we are enjoying will encourage the water plants to photosynthesise and produce oxygen by day but, by night, these plants, along with all the other organisms in the pond, will be using all of this oxygen for respiration.   Even during daylight, there will be areas of the pond where the demand for oxygen will exceed the supply that the plants can pump out and which can diffuse in from the air above the pond.  Together, this will create the anerobic, sulphide-rich conditions that Chromatium needs.

Bearing in mind the shortage of oxygen in the pond and remembering that sulphide is, itself, toxic, the anecdotal deaths of ducks and fish is likely to be due to the same set of factors that led to the Chromatium bloom, rather than a consequence of the bloom itself.   I did find a few reports of toxins produced by species Chromatium but not enough to make me think that this is a widespread problem.  There are easier explanations for the problems at hand and, probably, fairly easy solutions were the problem to persist.   Some judicious weeding and, possibly, dredging would reduce the amount of organic matter in the bottom of a pond and a nice ornamental fountain would keep the water well oxygenated.  Then, of course, we could always wish for a cool damp August which would stop those pesky plants and bugs using up all that oxygen with their reckless respiration …

Note and references

Thanks to Dave John for pointing me in the direction of Chromatium when I was first trying to name this organism

Hurlbert, R.E. & Hurlbert, I.M. (1977).  Biological and physicochemical properties of the lipopolysaccharide of Chromatium vinosum.  Infection and Immunity 16: 983-994.

Nicholson, G.L. & Schmidt, G.L. (1971).  Structure of the Chromatium sulfur particle and its protein membrane.  Journal of Bacteriology 105: 1142-1148.

 

 

More pleasures in my own backyard

Back in early July I wrote about a visit to a pond in a local nature reserve (see “Pleasures in my own backyard”) and ended with the hint that there was one other abundant alga there that I was unable to name at the time.  I was reticent about naming it, as it seemed to be a rare alga and the habitat where I had found it did not match the locations where it had been found to live.

I’ve now shown it to Brian Whitton and he has joined me on another excursion to the same pond, and I can confirm that it is, in fact, Chroothece richteriana, a freshwater red alga.   We’ve met (and even eaten) red algae several times over the lifetime of this blog (see “More from the Lemanea cookbook …”), but Chroothece is different in that it does not form filaments or thalli, but lives in mucilaginous masses.   The individual cells, each of which are ovoid, with a single star-shaped chloroplast, live embedded within this mass.

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A colony of Chroothece richteriana growing on marl-encrusted rocks from Crowtrees Pond, County Durham, July 2016.  Scale bar: 10 micrometres (= 1/100th of a millimetre).

This is a species that was, until recently, known only from two very old records. However, searches over the past few years have found it growing at a number of different locations.  There are now half a dozen locations in the UK, plus one in the Isle of Man.   Interestingly, the population at Crowtrees matches these other records in respect to the underlying geology – limestone – which yields very hard water, but differs in being permanently submerged.  The other records are from seepages and other semi-aerial habitats.   The population at Crowtrees formed a thin film that was firm to the touch due to the deposition of calcite crystals within the matrix.   There were also some cyanobacterial filaments mixed in amongst the Chroothece, as well as the diatoms that I mentioned in the previous post.  I suspect that the snails that I observed on my earlier visit were scraping up a mixture of all these species from the thin surface layer that had not yet had time to become hardened by calcite crystals.

One theory for the success of Chroothece here is that habitats such as this are naturally low in phosphorus, an essential nutrient that is naturally scarce but which is relatively insoluble and consequently is precipitated out of the water along with the calcite.   Studies in Spain (in a river, rather than a seepage or pond) showed that Chroothece shares the characteristic of several other algae from this type of habitat, of producing enzymes that can scavenge phosphorus from tiny particles that are suspended in the water.  The enzymes are thought to be concentrated in the mass of mucilage (which is actually formed from the organism’s stalks)

Ironically, our excursions to Crowtrees Nature Reserve have become more frequent over the past year or so as our usual running and walking beats in the countryside around Bowburn have been changed as a local quarry expands its activity (seen in the gouge in the skyline in the picture below).  The pond, itself, looks natural, but local drainage is strongly influenced by mining and quarrying.  The area around here, especially associated with the Permian limestone, abounds in nature.   But whether or not this nature is natural is a topic for another day …

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The view from Crowtrees Nature Reserve towards the Tarmac quarry, July 2016.

References

Aboal, M., García-Fernández, M.E., Roldán, M. & Whitton, B.A. (2014).  Ecology, morphology and physiology of Chroothece richteriana (Rhodophyta, Stylonematophyceae) in the highly calcareous Río Chícamo, south-east Spain.  European Journal of Phycology 49: 83-96.

Pentecost, A., Whitton, B.A. & Carter, C.F. (2013).  Ecology and morphology of the freshwater red alga Chroothece in the British Isles.  Algological Studies 143: 51-63.