Out of my depth …


I was about to start writing up an account of my latest visit to Castle Eden Dene, when I realised that I had forgotten to describe my previous visit, back in March.   I’ve already described a visit in January, when the stream was dry (see “Castle Eden Dene in January” and “Tales from a dry river bed”) and promised regular updates through the year.   It seems that, amidst all the travel that filled my life over the last three months, I overlooked the post that I should have written about the visit that I made in early March.

Whereas the river was dry in January, rain during February meant that, when I returned to the Dene on 11 March, some rather turbid water was flowing down the channel on its short journey to the North Sea.   There is, finally, something more like a stream habitat from which I can collect some diatoms.

Many of the diatoms that I found in March belonged to taxa that I had also seen in January; however, the proportions were quite different.   In some cases, species that were common in January were less common now (e.g. Humidophila contenta*) but there was a small Nitzschia species with a slightly sigmoid outline that was very sparse in the January sample but which was the most abundant species in the March sample.  I’ve called this “Nitzschia clausii” but the Castle Eden Dene population does not fit the description of this perfectly.   A lot can change in a couple of months, especially when dealing with fast-growing organism such as these, as my posts on the River Wear showed (see “A year in the life of the River Wear”).  Castle Eden Burn’s highly variable discharge just adds another layer of complication to this.


Diatoms from Castle Eden Dene, March 2019:   a. – e.: Nitzschia cf clausii; f. Tabularia fasiculata; g. Tryblionella debilis; h. Luticola ventricosa; i. Luticola mutica; j. Ctenophora pulchella.  Scale bar: 10 micrometres (= 1/100thof a millimetre).   The picture at the top of the post shows Castle Eden Burn at the time that the sample was collected.   

Nitzschia clausii is described as being “frequent in brackish freshwater habitats of the coastal area and in river estuaries, as well as in inland waters with strongly increased electrolyte content”.   A couple of the other species from this sample – Ctenophora pulchella and Tabularia fasiculata (both illustrated in the diagram above) – have similar preferences.    My experience is that we do often find a smattering of individuals belonging to “brackish” species in very hard water, as we have in Castle Eden Burn.  Average conductivity (based on Environment Agency records) is 884 µS cm-1; however, values as high as 1561 µS cm-1.   The fluctuating discharge plays a role here, as any evaporation will serve to concentrate those salts that are naturally present in hard freshwater.   This should probably not be a big surprise: life in brackish waters involves adapting to fluctuating osmotic regimes so species that can cope with those conditions are also likely to be able to handle some of the consequences of desiccation.

Average values of other chemical parameters from 2011 to present, based on Environment Agency monitoring are: pH: 8.3; alkalinity: 189 mg L-1 CaCO3; reactive phosphorus: 0.082 mg L-1; nitrate-nitrogen: 1.79 mg L-1; ammonium-nitrogen: 0.044 mg L-1.   There is some farmland in the upper catchment, and the burn also drains an industrial estate on the edge of Peterlee but, overall, nutrient concentrations in this stream are not a major concern.   The Environment Agency classifies Castle Eden Burn as “moderate status” due to the condition of the invertebrates but does not offer any specific reason for this. I suspect that the naturally-challenging habitat of Castle Eden Burn may confound assessment results.

I’ve also been given some data on discharge by the Environment Agency which shows how patterns vary throughout the year.  The two sampling locations are a couple of kilometres above and below the location from which I collect my samples and both have more regular flow.  However, we can see a long period between April and September when discharge is usually very low.   The slightly higher values recorded in July are a little surprising, but are spread across a number of years.   It is also, paradoxically, most common for the burn to be dry in July too: clearly, a month of extremes.  As my own visits have shown, it is possible for the burn to be dry at almost any time of the year, depending on rainfall in the preceding period   The dots on the graph (representing ‘outliers’ – records that exceed 1.5 x interquartile range) show that it is also possible to record high discharges at almost any time during the year too.  I should also add that, as I am not a hydrologist, I am rather outside my comfort zone when trying to explain these patterns.  I would have said ‘out of my depth’ though that’s not the most appropriate phrase to use in this particular situation.


Discharge in Castle Eden Burn, as measured by the Environment Agency between 2007 and present.   Measurements are from NZ 4136 2885 (‘upstream’) and NZ 45174039 (‘downstream’).  

* Note on Humidophila contenta:it is almost impossible to identify this species conclusively with the light microscope as some key diagnostic characters can only be seen with the scanning electron microscope.   However, all members of this complex of species share a preference for intermittently wet habitats so these identification issues are unlikely to lead to an erroneous ecological interpretation.  It is probably best to refer to this complex as “Humidophila contenta sensu lato” rather than “Humidophilasp.” order to distinguish them from those species within the genus that can be recognised with light microscopy.


Lange-Bertalot, H., Hofmann, G., Werum, M. & Cantonati, M. (2017).  Freshwater Benthic Diatoms of Central Europe: over 800 Common Species Used in Ecological Assessment. English edition with updated taxonomy and added species.  Edited by M. Cantonati, M.G. Kelly & H. Lange-Bertalot.  Koeltz Botanical books, Schmitten-Oberreifenberg.


When is an icon not an icon?


Yet another change in location, this time to Florence for a wedding, but with some time set aside to gorge myself on early Renaissance painting.   That means traipsing around a lot of churches (because much of the best Italian art remains in situ) and a long queue to get into the Ufizzi gallery (because some of it doesn’t), emerging at the end footsore and with more questions than answers.

Having immersed myself in Eastern Orthodox imagery earlier this year (see “Secular icons?”) my first response on looking at the earliest works by Giotto and Cimabue was “those are icons”.  Stylistically and in subject matter, there is nothing to distinguish them from contemporary Eastern Orthodox icons: the flat, gilded backgrounds, the poses of the Madonna and child, and the saints, are all identical.  That made me wonder if the Medieval believers had approached these images in the same way that an Orthodox Christian would have done, in which case we need to think of the Renaissance not just in the conventional art-historical terms (epitomised by Kenneth Clark’s Civilisation) but also in terms of a change in belief.    This is important because, in most cases the artists would have been working to strict instructions from their clerical paymasters and would not have had much latitude to experiment with new designs.

A case in point is Giotto’s Madonna and Child with four saints, which looks very much like a row of icons on an Orthodox iconostasis. Except that this was originally altarpiece and that, itself, tells a story.   The Orthodox iconostasis stands between the priest who conducts the eucharist and the congregation whereas a Catholic altarpiece sits behind the altar, so that the congregation (that part beyond the rood screen at least) can see the ceremony and, in particular, the part when the priest elevates the host.   Theological developments in the 13thcentury, therefore, drove changes in the arrangement of church furniture and, in turn, led to some of the changes that we see in art during this period.


Giotto: Madonna and Child with St Nicholas, St John the Evangelist, St Peter and St Benedict the Redeemer.  Tempera on wood, 1337.   Ufizzi Gallery, Florence.

It is not just the position of the image that changed in Catholic churches during Medieval times: subject matter also changes from schematic images painted to prescribed formulae to styles that demanded more mental engagement by the viewer.  Look at Gentile da Fabriano’s altarpiece depicting the Adoration of the Magi, painted about a century after Giotto’s Madonna and Child.   The Madonna and child are still present but are now set in a context that would allow the viewers to imagine that they were participants at the original event.   Note, too, how the subjects in the picture are dressed in contemporary attire and original audiences might also have recognised the patron and members of his family painted into the front of the crowd.   At one level, these altarpieces function as a “poor man’s bible”, bringing elements of the Gospel to the largely illiterate congregations but, at the same time, they are also drawing the viewers into the story, ensuring that they are not just passive observers and, in turn, demanding a response.


Gentile da Fabriano’s Adoration of the Magi.  Tempera on wood, 1420. Ufizzi Gallery, Florence.

As the fifteenth century progresses, we see the influence of the Renaissance in the images growing. In particular, a better understanding of linear perspective allowed artists to place the characters in their paintings in more plausible settings, drawing the viewer into the pictorial space.   Fra. Angelico’s Annunciation is painted onto a wall at the top of a staircase leading to monk’s cells in the Convent of San Marco, so the engagement with the viewer would be brief: no more than a short pause and a prayer before moving on.   The quiet scene depicted here is, perhaps, better suited to a monastery’s cloisters than the busy-ness that we saw in the Adoration of the Magi but, by focussing on just two people, pictures of the Annunciation create spaces that need to be filled if the illusion of pictorial depth is to be maintained.   And so we see, in the background of both Fra. Angelico’s and Leonardo’s Annunciations, the first tentative steps at depicting landscapes.


Fra. Angelico’s Annunciation at the Convent of San Marco, Florence.  Fresco, 1437-1446.


Leonardo da Vinci’s Annunciation. Oil and tempera on wood, 1472-1474.  Ufizzi Gallery, Florence.

The painting style may have developed through the early Renaissance but one feature that all these pictures still share with their Gothic predecessors, and with Byzantine icons, is that they are still “applied art”: each was painted with a particular purpose in mind, whether for a church or a monastery, and 21stcentury notions of aesthetics have to bear this in mind.   On our trip to Florence this aspect was exemplified by Ghirlandaio’s The Last Supper, also at the Convent of San Marco.  This is in rather better condition than Leonardo’s depiction of the same scene in Milan (which is about a decade younger) but is similar in other ways (some think that Leonardo may have been inspired by Ghirlandaio’s treatment of the subject) and, significantly, was also painted life-size onto the wall of a refectory.   Once again, we can see clever use of linear perspective to create an illusion of depth and, in the background, trees that suggest that, instead of looking at a flat wall we are, in fact, looking into an extension of the room that we are in which, in turn, has windows that look out onto a garden.   That gives us an important clue to unlocking the meaning of the image.

The Refectory where we find The Last Supper is now the gift shop for the San Marco museum, but there are wooden benches along two of the walls where you can sit down and try and put yourself into the place of the monks and their visitors who would have eaten their meals here.   The painting creates the illusion that they were eating in a room that seemed bigger than it really is, and where there were a dozen or so extra guests whose presence was a constant reminder of one of the most important events in the Gospels.  This is the acme of Renaissance thinking: scientific and mathematical principles being utilised to create a work of art that, in turn, synergised man’s relationship with God.   C.P. Snow described what he saw as a profound gulf between arts and sciences in the Two Cultures, written in 1959.  Even then he could conceivably have extended this observation to three cultures by including religion too.  That would have been an anathema in the fifteenth century, when the boundaries between art, science and spirituality were much more fluid.  We’ve learned a lot in the intervening five hundred years but, at the same time, there is much that we have forgotten to remember.


Domenico Ghirlandaio’s The Last Supper in the Small Refectory at the Convent of San Marco, Florence.  Fresco, 1486.


The church of Santa Croce rising above the rooftops of central Florence in May 2019.    The photograph at the top of the post shows a view of Florence from Fiesole.

More algae from Shetland lochs …


I’m taking you back in the Shetland Islands for this post, and onto the remote moorlands of northern Mainland.   When I visited this particular loch in 2016, I noticed a lot of slippery filaments of Batrachospermum attached to the sides of the cobbles in the littoral zone (see “Lucky heather …”).   This time around, I explored further around the edge of the loch and, in the south-west corner noticed prolific growths of algae in the shallow peaty water.  Closer inspection showed that these, too, were the red alga Batrachospermum and, though they were not fertile, Dave John suggests that they are likely to be B. turfosum Bory.


Tufts of Batrachospermum turfosumin the littoral zone of Lamba Water, north Mainland, Shetland Islands, May 2019.   The picture frame is about 15 centimetres across. 

If you have a hand lens you can just about make out a bead-like structure when observing Batrachospermum in the field; however this becomes much clearer with higher magnification.   I think it looks like a bottle-brush when seen under the microscope at low magnification, with whorls of side-branches arising from the central filament.  At higher magnification, these filaments can be seen to have a bead-like structure, with cell size gradually reducing with distance from the centre.

What you cannot do in the field is separate Batrachospermumfrom the closely-related genus Sheathia(see “News about Batrachospermum… hot off the press”).   I usually tell people that, for a general overview of the condition of a stream or lake (for example, as part of the UK macrophyte survey technique), then simply recognising that you have “Batrachospermum” (meaning Batrachospermum or Sheathia) should be enough.   In my experience, the presence of Batrachospermumis usually a good indication that the water body is in a healthy condition.  However, I have been told that Batrachospermumis often found growing prolifically in very enriched conditions in southern chalk streams, which would challenge this assumption.   This may be because the species that are found in southern chalk streams are different to those that I encounter in my more usual haunts in northern England and Scotland.  But it is also possible that the factors I described in “The exception that proves the rule …” pertain in those cases too.


Filaments of Batrachospermum turfosum from Lamba Water, north Mainland, Shetland Islands, May 2019.   The upper photograph shows a low magnification view of a filament (about 350 micrometres, or 0.35 millimetres, wide) whilst the lower image shows a whorl of side branches arising from the main stem.  Scale bar: 20 micrometres (= 1/50thof a millimetre).  

We often run into this dilemma with filamentous freshwater algae: it is reasonably straightforward to identify the genus but we need reproductive organs to determine the species.  As they seem to survive quite happily in the vegetative state our understanding of the ecology of individual species (rather than the genus as a whole) is scant so it is hard to tell whether there is value in that missing information or not.   In a few cases – this is one – better taxonomic understanding has revealed that we may not even be dealing with a single genus but the lists used for applied ecological surveys still persist with the old concepts.

This creates a toxic spiral of consequences: it is hard to split into species so most people don’t bother. Because we don’t bother, our interpretations are based on generalisations drawn from the behaviour of the genus.  This means we don’t generate the data needed to demonstrate the value (or otherwise) of the effort required to go from genus- to species-level identifications.   So we carry on lumping all records to genus (or, in this case, a pair of genera) and accept a few records that our out of line with our expectations as “noise”.  The situation is probably worse in the UK than in many places because there are very few people in universities specialising in these organisms and, as a result, no-one is producing the data that might break us out of this spiral.

We found Batrachospermum turfosum in a few other locations during our visit, but nowhere, even in nearby lochs, was it in such quantity as we saw in Lamba Water.   Chance might play a part in determining its distribution on a local scale but that ought to be the explanation of last resort rather than the go-to answer when we are worryingly short of hard evidence.



Notes from Windermere


Just before the trip to the Shetland Islands I wrote about in the previous post, I spent two days in the Lake District teaching a course on identifying macroalgae for the Freshwater Biological Association.  It coincided with a period of gorgeous weather, showing Windermere at its absolute best (as the photo at top of the post shows).  Only a month ago my wheels were spinning in the snow on Whinlatter Pass (see “How to make an ecosystem (2)”).

Looking up Windermere towards the high peaks of the Lake District’s volcanic centre, I find myself reflecting on how geology creates the diversity in landscapes and aquatic features that, in turn, creates variety in the microscopic flora and fauna (see “The Power of Rock”).   A nuanced understanding of the aquatic world requires one to view the grand panorama at the same time as focussing on organisms that are scarcely visible with the naked eye.

One of the locations that we visited during the course was Cunsey Beck, which flows out from Esthwaite Water and, a few kilometres later, into Windermere.   Esthwaite is one of the more productive of the lakes in this region and we usually find a healthy crop of algae in the beck.   This year was no exception and, amongst the different forms we collected were some long straggly growths that had a slighty gelatinous feel.  Back at the laboratory we put part of one of these growths under the microscope and saw a large number of individual cells set in a jelly matrix.   This identified the alga as Tetraspora gelatinosa, a green alga that I have written about before (see “More from the Atma River …”) although not for some time.


Tetraspora gelatinosafrom Cunsey Beck, Cumbria, May 2019.   The picture frame is about five centimetres wide.

The genus Tetraspora gets its name from a mode of division that leaves many of the daughter cells in groups of four (visible in the lower illustration).  These, in turn, are embedded in mucilage, and repeated divisions can lead to growths becoming visible with the naked eye.   Three species have been recorded from Britain and Ireland, of which the Cunsey Beck population is most likely to belong to T. gelatinosa.   In the past, it might have been called Tetraspoa lubrica, which has a more tubular thallus; however, this is now thought to just be a growth form of T. gelatinosa that is associated particularly with fast-flowing rivers.  As far as I can tell, no-one has performed any detailed molecular genetic studies on this genus to better understand the relationships between these different growth forms so we will have to go with current convention for now.


Tetraspora gelatinosaunder the microscope.   Cells in the foreground are about ten micrometres in diameter.   Photograph by Hannah Kemp.

I’ve seen Tetraspora in a wide range of habitats – on stones in fast-flowing, relatively soft water rivers in Norway and growing on plant stems in the littoral zone of hard water ponds in Ireland.   Most of my records are from the spring, though I should add that spotting some of the smaller gelatinous colonies (barely more than near-transparent dots on the stone surface) does take some practice and I suspect that I have missed it on a few occasions too.

The microscopic image of Tetrasporawas taken during the course using a Carson Hookupz, a neat device which allows a smartphone to be attached to a microscope (or any other optical device).   It takes a little fiddling to get the set-up right but, once this has been achieved, the quality of pictures we obtained was excellent.   My microscope engineer tells me that he is selling large numbers of these to schools and colleges as it means that students can capture images during practical classes that they can subsequently use in reports or just (as was the case during our course) as an aide mémoire.


The Carson Hookupz 2.0 as it comes out of the box (left) and (right) in action during the Identifying Macroalgae course at the Freshwater Biological Association.


Looking north from Miller Ground towards the central Lake District peaks as the sun sets.  The photograph at the top of the post was taken from nearby but shows the view in early morning.  


Hyperepiphytes in the Shetland Islands


I was lucky enough to spend a couple of days in the Shetland Islands during last week’s spell of warm weather and spent one of my mornings there hiking in shirtsleeves across moorland to a remote loch.   Good infrastructure is a legacy of the Shetland Islands’ association with the oil industry, and this includes a strong mobile network, meaning that I managed to find this particular loch using the Ordnance Survey maps on my smartphone. I would not normally rely upon a mobile signal to navigate across such remote terrain but in Shetland it is often possible.  I would, nonetheless, recommend keeping a paper map and a GPS in your kit just in case, as I did lose the signal on a few occasions during my stay.

Most of the lochs in the northern part of mainland Shetland are shallow, peaty water bodies, with soft water and relatively sparse assemblages of aquatic plants.   Parts of the littoral zone of this particular loch, however, had extensive growths of submerged mosses.  It is a long time since I was proficient at identifying aquatic mosses but these clumps look likeWarnstofia fluitans to me, though I am willing to be proved wrong.  I did try to remove some leaves and have a proper look but that task was complicated by tufts of attached filamentous algae.   In their submerged state, these formed distinct clusters at intervals along the straggly stems of the moss but, once removed, the filaments collapsed to smother the leaves and confound my attempts to run a scalpel blade along the stem.


Submerged colonies ofWarnstorfia fluitans(?) smothered byOedogoniumfilaments in Gossa Water, north Mainland, Shetland (HU 4354 6047). Gossa Water (one of five that share this name in the Shetland Islands!) is illustrated in the photograph at the top of this post.

The filamentous alga proved easier to unmask: the unbranched filaments, reticulate (net-like) chloroplasts and distinctive ‘cap cells’ all identifying it as the green alga Oedogonium.  As is often the case, however, the populations lacked any sexual organs so it was impossible to know which species (see “The perplexing case of the celibate alga“ and, for a rare case of a sexually-mature filament, “Love and sex in a tufa-forming stream”).   Abundant epiphytes can be another feature of Oedogonium: unlike several other filamentous green algae it produces little mucilage which makes it easier for diatoms, in particular, to colonise.  As well as colonies of needle-shaped cells of Fragilaria gracilis there were also several Achnanthidium cells and, entangled around the filaments and the moss, chains of Tabellaria flocculosa.   Given that the Oedogonium was, itself, an epiphyte, these diatoms are ‘hyperepiphytes’, a term that attracts remarkably few Google hits, almost all associated with lower plants.

The ‘cap cells’ are one of the most distinctive features of Oedogonium and results from a distinctive mode of cell division that leaves rings of scar tissue at the point where the two cells split.   That we see four or more of these scars on a few cells whilst the great majority have none suggests that we are looking at a primitive form of specialisation, with a few cells in a filament being responsible for all the cell division.  What is more, these cap cells are also often the ones that form oogonia (see “Love and sex in a tufa-forming stream” for an illustration of this) and asexual zoospores, so there must be something slightly different in the biochemistry within these cells that drives these processes.   However, at this point the formal scientific literature goes strangely silent apart from a single paper published in 1962.  Curiously, the evolution of multicellularity is one of those big questions that attract a lot of top academics (see the reference to a recent paper in Nature Scientific Reports below)  whilst a genus of algae that seem to show some faltering first steps towards specialisation of some cells are largely ignored.  Another case of the “trailing edge” of science?


Oedogonium filaments growing on Warnstofia fluitans in the littoral zone of Gossa Water, north Mainland, Shetland, May 2019.   The arrow on the top image shows the “cap cells”.   Note also the cluster of Fragilaria gracilis(plus a few cells of Achnanthidium) on the lowermost filament and, in the middle image, two of the many cells of Tabellaria flocculosa that were entangled with the Oedogonium filaments and moss stems.  Scale bar: 20 micrometres (= 1/50thof a millimetre). 


A zoospore being released from a filament of Oedogonium.  This series of photographs was taken by me in about 1993 and I have no details of the location from which it came.  The filament is about 40 micrometres (= 1/25thof a millimetre) in diameter.


Herron, M.D., Borin, J.M., Boswell, J.C., Walker, J., Chen, I-C. K., Knows, C.A., Boyd, M., Rosenzweig, F. & Ratcliff, W.C. (2019).  De novo origins of multicellularity in response to predation.  Nature Scientific Reports 9, Article number: 2328

Rawitscher-Kunkel, E. & Machlis, L. (1962).  The hormonal integration of sexual reproduction in Oedogonium.   American Journal of Botany 49: 177-183.


Sightseeing in Shetland: the tombolo (sandy isthmus) linking St Ninian’s Isle with Mainland in the Shetland Islands, May 2019.

Beyond the Tower of Babel …


A week after I return from China, I was off on my travels again; this time to Vienna for a workshop between molecular ecology specialists and ECOSTAT, the committee of Member State representatives who oversee ecological aspects of Water Framework Directive implementation.   As ever, I found some time to visit some art galleries around the meeting and, as Vienna has one of the most impressive collections of paintings by Pieter Brueghel, I could not resist spending some time in front of his “Tower of Babel”.  A few years ago I cheerfully included this picture in a talk on EU ecological assessment methods, as we tried to make sense of the myriad national approaches.   Three years after the Brexit vote, however, it seems to better reflect UK domestic politics where, ironically, language is one of the few things that all protagonists do have in common.

The River Danube seems to encapsulate the reasons why Europe needs collaborative thinking on the state of the environment.  It is the second longest river in Europe, after the Volga, and flows through ten countries, with tributaries extending into nine more.   Eight of the nine countries through which the river flows are members of the EU (the ninth, Serbia, is in the process of joining) so the river represents a case study, of sorts, on whether EU environmental policies actually work.   This is not just an academic question: ecologists are generally in favour of integrated management of entire catchments whilst the EU operates on a principle of “subsidiarity”, which means that decision-making is devolved to the lowest competent authority (individual Member States in the case of the environment).   Finding the right balance between these principles takes a lot of patient discussion and is one reason why EU decision-making can appear to be agonisingly slow.


Pieter Bruegel’s “Tower of Babel” in the Kunsthistorisches Museum in Vienna.

And there are more problems: the Water Framework Directive evaluates the sustainability of water bodies by their naturalness yet very large rivers such as the Danube have been very heavily modified by human use for centuries.   The river has been broadened, deepened and impounded, and its banks have been straightened and strengthened in order to make it navigable, and there is a huge human population, with associated industry, living on its banks.  The stretch of the Danube along which I walked on my last morning in Vienna was also lined with embankments to protect the surrounding land from flooding but these, at the same time, cut the river off from the ecological benefits of the floodplain.

What hope for a large river such as the Danube in the face of all these challenges?   First of all, when dealing with rivers such as these we need to adjust our expectations, recognising that they are so central to the economic life of the regions through which they flow that there are limits to their capacity to ever resemble truly natural rivers.   Once we have done this, we can start to unpick the challenges that can be addressed by individual Member States.  In the case of water quality, in particular, the story for the Danube is encouraging and European environmental legislation has played its role in this process.  By the time the Danube reaches the borders with Romania, for example, nutrient concentrations are low enough for many of the benthic algal-communities to meet criteria for “good ecological status”.

You can see this in the graph below, from a paper that we’ve published recently.   The Romanian sites are largely clustered at the top left hand side of the graph, relative to data from other countries – indicating low phosphorus concentrations and good ecology (expressed as “ecological quality ratios”, EQRs).   Thanks to an extensive exercise that took place a few years before I started grappling with the Romanian data, we already had a consensus view of the EQR boundaries for high and good status, and most of the Romanian data fits into the band representing “good status”.  That’s encouraging and whilst these communities are just one element of a much more complex ecosystem, but it is a clear step in the right direction.


The relationship between dissolved phosphorus and ecological status of the phytobenthos (expressed as the Ecological Quality Ratio, EQR, based on the intercalibration common metric (which gives a harmonised view of status between Member States).   Horizontal lines show the average position of “high” (blue) and “good” (green) status boundaries.   RO = Romanian data; XGIG = data from other Member States.   See Kelly et al. (2018) for more details.  

Romania is, of course, a long way downstream from where I was standing in Vienna.  Before the Danube gets there it has to cross Slovakia, Hungary and Serbia.  The river also forms the boundary between Romania and Bulgaria for about 300 kilometres, so it is important that there is joined-up thinking between those responsible for water quality on the two opposite banks.  That’s why the EU is so important for the environment on a pan-European scale.  It is easy for those of us crammed onto our insignificant archipelago in the north-west corner of the continent to overlook this, but the Danube is really a great success stories for European environmental collaboration and, indeed, a reason for staying with this ambitious project into the future.   Too late, I know, but it needs to be said.


Kelly, M.G., Chiriac, G., Soare-Minea, A., Hamchevici, C. & Birk, S. (2018).  Defining ecological status of phytobenthos in very large rivers: a case study of practical implementation of the Water Framework Directive in Romania.  Hydrobiologia 828: 353-367.


Sightseeing in Vienna: Stefansdom, the historic cathedral in the city centre and the Ferris wheel at the Prater amusement park, which played a starring role in Graham Greene’s The Third Man.

The limits of science …


Back in a rather smoggy Chengdu I find it easier to describe the environmental problems that China faces than it is to propose solutions but perhaps that is the nature of my calling. Coming from a scientific background, I tend to think primarily in terms of technological ‘fixes’.  I help to define ecological and chemical targets in order that a motley band of regulators and engineers can restore a lake or river to good ecological status.  But these targets, as is the case with most legislation, really define the lower limits of acceptable behaviour, setting a threshold for the point at which the state should intervene to limit bad behaviour.  Achieving ecological targets does not, necessarily, equate to morally good behaviour.

This brings to mind a quotation from the US environmental lawyer Gus Speth: ‘I used to think the top environmental problems were biodiversity loss, ecosystem collapse and climate change. I thought that with 30 years of good science we could address those problems.  But I was wrong.  The top environmental problems are selfishness, greed and apathy … to deal with these we need a spiritual and cultural transformation – and we scientists don’t know how to do that.’

The only part of that statement with which I disagree is the need for 30 years of good science. In the case of aquatic ecosystem health, I think we already know what needs to be done in broad terms.  Reconciling the investment required with the ‘willingness to pay’ is as big a challenge in China just as much as in Europe.   Willingness to pay recognises that environmental improvements come with an ‘opportunity cost’ – a pleasure that has to be foregone.   And by focussing attention on selfishness, greed and apathy, Gus Speth is spot on, for China just as for the West.

The irony of the situation in China is that two of its most prominent religions – Buddhism and Daoism – have a philosophy that should, in theory, provide a justification for a less materialistic lifestyle but which, somehow, exist in an uneasy equilibrium with modern China’s capitalism.  This is amply summed up by the photograph at the top of this post: showing the Daci Bhuddhist temple close to the centre of Chengdu overlooked by the gleaming skyscrapers that encapsulate modern Chinese capitalism.   The monks and continue their devotions just a few metres from an upmarket shopping mall that has been built around this temple complex, complete with Western brands such as Gucci, Dior, Louis Vuitton and Cartier (see “Reflections from the banks of the Yangtze” for another of these paradoxes).


The shrine to Guanyin, goddess of mercy and compassion, at the Yuántōng Temple in Kūnmíng. 

It maybe that we in the West see Buddhism, in particular, through rose-tinted spectacles.  The reality is that most Chinese are only nominally Buddhist (often with a seasoning of Daoism and Confucianism too) rather than strict in their adherence.   Somehow, these eastern religions co-exist with materialism, just as Christianity does in the West.   The infrastructure of all religions depends upon individuals producing more than they need for basic sustenance and being prepared to donate part of the surplus as ‘alms’ or ‘tithes’ in return for the benefits that the religion confers.  This is exemplified by the prominent shrines to Guanyin, the goddess of compassion and mercy (roughly equivalent to the Virgin Mary in Catholicism) and a mediator between worshippers and the divine.   The temple becomes a focus for transactions, rather than for reflection and transformation.  In this way, Buddhism can be one more part of a system that indirectly encourages wants and desires even if the religion, in theory, is about transcending these.

I would encourage you to read Kate Raworth’s Doughnut Economics, for an inspirational look at how modern economic theory has resulted in an unsustainable situation.  She also proposes solutions yet, for these to work, each of us will have to accept that creating a sustainable world will carry a considerable opportunity cost.  That will mean an adjustment in expectations, and a need to find a source of contentment that is independent of materialism.   The environment, to be blunt, cannot be considered without also thinking about economics.  At the same time, radical thinking about economics will need to be accompanied by a deeper shift in behaviour and attitudes if it is to succeed.  That pushes us to the very edges of rationalism, and into the realms of mysticism.

And, yes, this whole post was written in China so I have to admit to an element of hypocrisy if I am to write about a more sustainable world whilst still indulging in long-distance air travel.  More about that in a future post.


Pagodas at the Chongsheng temple complex at Dàlī, with Ērhāi Hú in the background.


The Chongsheng temple complex at Dàlī, against the backdrop of the Cāng Shān mountains.