Hilda Canter-Lund competition 2017 winners

The winner of the 2017 Hilda Canter-Lund photography competition is Chris Carter for his image of the desmid Pleurotaenium coronatum var. robustum.   This is the second time that Chris has won the competition and his fifth time on the shortlist, confirming an already impressive reputation as a photographer of the algal world.   This particular image is of a specimen that was collected whilst on holiday in Newfoundland, Canada, and preserved in formalin.  This led to the loss of chloroplast colour but which, in turn, made the pore field at the end of the cell more obvious.

The technical skill behind this image is not immediately obvious unless you know the genus Pleuotaenium typically consists of cylindrical cells several times longer than wide.  This particular specimen is 45 micrometres (about 1/20th of a millimetre) in diameter but is almost half a millimetre long.  The challenge was increased because the 100x magnification oil-immersion objective which he used has a very shallow depth of field.  Chris had to suspend the cell in dilute jelly in a cavity tank not much deeper than its length.  Having done this, he agitated the cell with a length of fine wire and once it was no longer horizontal he could manipulate it by gently sliding the coverslip relative to the cell.  The photograph which won the competition is one of many attempts and, even so, Chris commented that the cell is probably a degree or so away from vertical even here but, he went on: “I thought the lighting was actually quite attractive with the bronze hue of the preserved wall contrasting with a blue tinge from the light source; even the very slight tilt perhaps suggests a monster (or a something) rising out of the deep.”

Pleurotaenium coronatum var. robustum.  The top left image is an apical view, showing the pores and the radial ring of tubercules (knobbly projections).  The lower image shows the cell in plane view.   All images by Chris Carter.

Chris Carter, Hilda Canter-Lund prize winner, 2013 and 2017.

The second prize this year was also awarded to a former winner.  Tiff Stephens won the competition last year with her photograph of Durvillaea antarctica in the intertidal zone of the sub-Antarctic Snares Islands.  This year, it was her photograph of the red alga Bonnemaisonia clavata that caught the judge’s eye.   This is a very different style of photograph to her winning entry from last year, taken using an Olympus DP20 camera on a dissecting microscope.   The row of spheres along the secondary axis (“stem”) contain female reproductive cells and the prominent branchlet in the centre right is 1.5 mm long.

“Cystocarp Central”: Tiffany Stephen’s winning entry for the 2017 Hilda Canter-Lund photography competition. 

Though the style of the picture is very different to last year’s entry, it shares with that image an encapsulation of the “decisive moment” (see “How to win the Hilda Canter-Lund competition”). Tiff comments that many of her images are “opportunistically taken while sprinting around doing fieldwork”.  In this particular case, she was on a fun dive outside of Victoria, British Columbia (Canada), collecting seaweeds to look at later, with a view to possibly making herbarium pressings.   She saw dense lumps of Bonnemaisonia clavata, a species with which she was not familiar, at depths between 5 and 10 metres on semi-exposed reefs and collected some to have a closer look later.

The two images represent the two extremes of photographing the microscopic world: Chris applied a great deal of technical skill and ingenuity to create an aesthetically-pleasing image from difficult subject matter whilst Tiff saw an elegant composition drift into view as she scanned around recently-collected field material.  Both photographers have an “eye” for a good composition and the patience and technical skill needed to capture a fine image when the occasion final presented itself.   They are also – and this is important – keen field scientists, grabbing samples out of sheer curiosity and then marvelling as new and fantastical worlds open up to them under the microscope.  Both worthy winners and, with John Huisman (winner in 2014, shortlisted five times), now form algal photography’s “superleague”: the people to beat in 2018!

Tiff Stephens surrounded by Macrocystis in Alaska earlier this year.  Follow Tiff on Twitter at @tiffanybot to see more examples of her photography.

Hilda Canter-Lund competition shortlist 2017

The shortlist for the annual Hilda Canter-Lund competition to find the best algal photograph has just been uploaded to the British Phycological Society website and here is a quick guide to the images.  No less than three previous winners have made it to the shortlist again, along with three newcomers, so it looks like being a particularly intriguing year.

2013 winner Chris Carter has made it to the shortlist for the fifth time with an apical view of the desmid Pleurotaenium coronatum var. robustum with an image that combines aesthetics and technical ability in his own inimitable manner (above left).   The desmid genus Pleurotaenium typically has cylindrical cells several times longer than wide, so getting a good image of one end of a cylinder that is about 1/20th of a millimetre in diameter is quite an achievement.   He is joined on the shortlist by 2016 winner Tiff Stephens, who switches style this year to offer a macroscopic view of female reproductive cells of the subtidal red seaweed Bonnemaisonia clavata, collected off the coast of Vancouver Island in Canada (above right).   The prominent branchlet in the centre-right with its own side branches is 1.5 mm long.

John Huisman shares with Chris Carter the honour of being the most shortlisted photographer in the competition, with five nominations including the winning entry in 2014.   His image this year shows the green alga Ulva stenophylloides, at the centre of a diverse assemblage (above left), photographed whilst snorkelling off the coast of Western Australia.   Heather Spalding, by contrast, makes her first appearance on the shortlist, with a view of Chara zylanica beds in a brackish lagoon in Hawaïi (above right).  Note the small snail making its way across the plants in the foreground, reminding us of the important role that macroalgae play in structuring ecosystems.

We go back to Australia – the D’Entrecasteaux Channel in Tasmania actually – for the next entry: Luis Henriquez’s image of a young plant of the brown alga Carpoglossum confluens emerging from a bed of Caulerpa trifaria (above left). As well as providing a striking image, Luis’ image also tells a story of marine eutrophication as the slow growing brown algae such as Carpoglossum are struggling to compete with the fast growing green algae such as Caulerpa.   Finally, Alizée Mauffrey brings a completely different style to the competition, with a collage of images of seaweeds exhibiting different functional traits (above right).   As well as telling a story about how different morphological, phenological and physiological traits combine to equip each species to inhabit a particular niche, Alizée also creates a pleasantly abstract composition.   She is also the first person to submit an image produced using a flatbed scanner rather than a camera (for more examples of this technique, see An Ocean Garden by Josie Iselin).

This shortlist is unusual in that there is only a single true micrograph and a single freshwater alga (both represented by Chris Carter’s image).   A number – using both the light microscope and scanning electron microscope – were submitted but the judges who selected the shortlist felt that most did not quite make the grade.  It was a close call in a couple of instances (and, in at least one case, some minor adjustments to contrast might have persuaded us) but that is the sad truth.  It may simply be that taking a really good image using a high power microscope is a more technically demanding task than photographing macroalgae in situ?   If nothing else, this does show just how good a photographer Hilda Canter-Lund was.

The final step in the competition is for the council of the British Phycological Society to vote for the winning entry.  After that, a second (but equal) prize will be awarded for the best of the shortlisted entries in a contrasting style (i.e. a micrograph is a photo of a macroalga wins and vice versa).   Both winners should be announced within the next couple of weeks so keep an eye on www.brphycsoc.org for the announcements.  And, while you are there, browse through the archives of pictures that we’ve accumulated since the competition started in 2009 and enjoy some of the remarkable and beautiful organisms that they portray.

How to win the Hilda Canter-Lund competition (3)

My two previous posts on the qualities that make a great image of an alga focussed on the ascetics of the image itself, and also identified major technical problems that confront those of us who want to take images of the microscopic world.   At this point, my own ability to write authoritatively on the subject peters out, so I have asked Chris Carter, who won the competition in 2013 and was shortlisted in 2010, 2011 and 2015, to write a guest post in which he shares his own extensive experience.

“Everything in optics is against the microscope photographer”: a guest post by Chris Carter

Chris-Carter

Everything in optics is against the photographer of the microscopic world, and the algal photographer in particular. Without cheating, there is limited scope to choose what is (or is not); in the field of view; the depth of focus is usually tight; the object size rarely matches the available field; no microscope objective can match the usable pixel count of a modern camera lens in conventional photography, and colours are, to say the least, difficult. Transmitted light photography has the additional problem of Beer’s law (remember!): make an object three times thicker and it will let through a ninth of the light, creating problems with the dynamic range.

The bottom line is that “adjustments” and some degree of image manipulation are necessary but these, in turn, place an onus on the photographer not to be dishonest with either the viewer or the organism.  The extent to which image manipulation is acceptable will depend upon whether the image is for a respected scientific journal, a competition, or for a Christmas Card. We cannot be too purist: the camera always lies and a modern digital camera works wonders in the background; what is colour anyway but an illusion derived from the eye and brain? For the holiday snapshot you are allowed to move the glass of beer out of the field of view first but you are not allowed to paste in a missing family member (or vice versa!) later. For the microscope image I suggest it is acceptable to remove objects that are spurious (e.g. floating limescale) and to use software tools to fuse images of the same object tastefully and honestly in the horizontal and vertical planes. In contrast, it is all too easy to add objects to an image to give a nice montage (e.g. of sparsely distributed planktonic forms) or to use false colours in an area that can be defined exactly by some other method. Similarly, other ‘composite’ images ( e.g. two views of the same object) have a place but may be difficult to make visually pleasing.

So, how do we go about this? The first necessity is to use a good image processing software package: there are lots of them and it isn’t easy to choose. I use Adobe Photoshop CS6. The first steps in processing a single image are to get the colours about right (there are separate sliders for each of the primary colours and filters for warming and cooling); for an image in transmitted light there will be overly dark and overly bright areas which the ‘shadow-highlight’ tool may fix easily. In more difficult cases adjustment the parameter ‘gamma’ can help: this tries to scale the dynamic range in the image to what is seen by the eye and to what comes over in a print or on a monitor: it is merely overcoming the limitations of the electronic and optical gadgets in use. Similar actions are performed by the ‘curves’ and ‘levels’ control: each allows the user to choose which colours and in which intensity to best convey information about the object in an aesthetic way whilst not wrecking its essential nature. At each pixel and in each primary colour the data will be stored as a (usually) 8 bit number giving 255 levels in total.  These levels need not be evenly spaced; ‘gamma’ for example can give more emphasis to the dark or the light areas whilst the other settings control which levels are used. Most digital cameras will be doing this in the background (even on a ‘raw’ setting) but my own camera does no pre-processing at all, which has advantages and disadvantages.

So much for colour: but there are still issues associated with depth of focus and field of view that need to be sorted out; these are both relatively easy to overcome technically but can create a considerable amount of work and have the potential to create taxonomic and artistic mayhem. I use two methods for producing images with an extended depth of focus both using separate images taken over the range of focus that is needed. The first is to use a ‘stacking’ software package such as ‘Helicon Focus’ (but there are others) and the second is to make use of ‘layers’ in Photoshop: each of these methods has its pros and cons but both need honesty and good sense as well as an eye on the “why am I doing this?” question.

Stacking with Helicon Focus tends to work better at lower magnifications: with a x100 oil objective curvature changes rapidly with focus and great care is needed; the software is easily confused and I did once introduce an extra row of punctae into a diatom! Good results at low magnification can be obtained with macroalgae such as the stoneworts, but even here taxonomic information can be lost in the process (e.g. the height difference between the primary and secondary cortex rows and the location of the spine cells). As I hinted above, there is always an ongoing and unresolved tension between the artist, the microscopist and the taxonomist!  At intermediate magnifications an image produced using Helicon Focus can look overly flat and artificial, despite being sharp. My own approach is to use a gentle touch to produce pictures that are primarily useful but very occasionally develop into an artistic masterpiece! By contrast, using “layers” in Photoshop requires human intervention to ‘paint in’ the wanted parts of different images.  For example, the desmid Micrasterias will rarely present in a sufficiently flat plane for a good image at high magnification; however, it is easy to judge what is closest to reality and to blend this in. Even here there are pitfalls: the end of the polar lobe in some species is normally out of plane or twisted….so again, what is the image for? A similar comment applies to the colonial green alga Pediastrum in which the peripheral cells have horns that are alternately up and down and the central cells often have surface granules.

micrasterias-crux-melitensi

The desmid Micrasterias crux-melintensis has many named forms and is fairly easily recognised.  It will never sit flat enough for a x100 oil lens but in this case nothing is lost by tasteful flattening with Helicon Focus  and layers. Or is it? How many people have seen the somewhat surprising apical and side views? (No wonder it does not sit flat!). These extra views show the need for gamma adjustment and colour correction since light beams will be modified after passing through such an object. Is this composite image of artistic or of taxonomic value only? The face view is made of 17 sub-images processed as two semi-cells that were stitched using Photoshop layers; some correction to colours and levels was also necessary.

thumbnail_pediastrum-boryan

There are many forms of Pediastrum boryanum but this is a particularly pretty one from Ulva growing on a wet cliff face; the red walls are real (perhaps manganese as suggested by Brian Whitton). This image borders on “cheating”: it was entered (no success) for a national wildlife contest but not for Hilda Canter-Lund competition (I don’t think she would have approved!). Should the horns have been flattened or left as obviously alternating?

After the issue of focus, there is still the problem of field-of view but it is really fairly easy to stitch together a matrix of images in the same plane, at least in simple cases. Photoshop has an option to do this and there are other similar packages; this is also another job that ‘layers’ in Photoshop cope with very well: adjacent overlapping images can be blended manually. It is more difficult of course if these adjacent images are themselves blends at different focus points……it just takes a long time to get right. The image of Tolypella glomerata that was a runner-up in the 2015 Hilda Canter-Lund competition was made of 75 sub-images (17×5 approx) and took two days to process! Each of the 17 in the xy plane was shot as a stereo pair, so there is also a matching anaglyph (3D image) made of 150 sub-images!

chris_carter_tolypella_hcl_

“Out of the pit”: Chris Carter’s image of Tolypella glomerata, shortlisted for the 2013 Hilda Canter-Lund prize.

thumbnail_chara-fragifera-a

This dark-field image showing the antheridia of Chara fragifera is made up of 28 sub-images: 4 horizontally and 7 for the vertical stacking; a protruding green filament has been removed (actually a rare Bulbochaete, but that is another story).

One final point, unresolved in my view and perhaps the most difficult of all is the issue of dynamic range. In transmitted light photography the intensity of difference between bright and dark can be nearly impossible to capture: well beyond the capability of the 8 bits of a normal camera and marginal even for an expensive cooled CCD instrument. Photoshop and other packages claim HDR ability (High Dynamic Range) using several images of different exposure: I have not personally had much success with this but have regularly used Photoshop layers to blend such images manually and regard this as acceptable in all cases (see the Rivularia cross-section below).

All the algae are amazing but even a retired physical scientist has to narrow things down a bit: I am trying to use photography to bring out the three dimensional aspects for identification and appreciation: diatom auxospores, desmids from unusual angles and macroalgae as 3D recreations such as anaglyphs and stereograms….but that is another story.

thumbnail_rivularia-xsect3

The cyanobacterium Rivularia presents many photographic challenges. This is a section of a nodule in transmitted light done for taxonomic purposes: in-focus bits of the calcification have been discretely blended in and the outermost part showing hairs is at a very different exposure to the core; colours are distorted by passing through the nodule and have been corrected. Three or four overlapping sections have been accurately joined to produce the final image.

Chris Carter, Nothampton August 2016.

Abstracting from reality …

Abstract_based_on_Sironi_Au

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 win the Hilda Canter-Lund competition (2)

My previous post on this subject (see “How to win the Hilda Canter-Lund competition”) considered the dichotomy between the “decisive moment” – the spontaneous recognition of the potential of a view to become a great image – and the painstaking preparation – and post-production work – that is often necessary to produce a really stunning image of the microscopic world.   In this post, I am going to take a step backwards, then approach the topic of photographing algae from a different angle.

Let’s take as a starting point a desire to simply provide a good representation of an alga in order to convey some essential information that allows someone else to recognise or name that organism.   You might try to simplify the background to throw the subject into sharper definition, and you will aim to get as much of the organism in sharp focus.   You will also try to offer the viewer an indication of scale, particularly important when dealing with the microscopic world.  A good example of such an image which made the shortlist in 2010 is Chris Rieken’s image of the desmid Micrasterias radiata.   You would be very pleased to open a guide to desmids and find an image as clear as this to help you identify your own specimens.

Rieken_Znafor_HCL_images

Left: Chris Rieken: Micrasterias radiata Prox (2010 shortlisted image); right: Petr Znafor: Freshwater phytoplankton dominated by desmids (2016, co-winner).

Compare Chris’ image with Petr Znachor’s image which won a prize in 2016.   Both are of desmids, but they are very different.  Chris has focussed on representation of the organism and has produced a beautifully crisp image whilst Petr has used the fact that some of the desmids in his image are not in sharp focus to create an aesthetically-pleasing pattern.   It is still, recognisably, of desmids, and you may be able to name the genera, yet it is harder to say exactly what species are present.   The two images, in other words, illustrate a tension between representation and abstraction that runs through many of the winning and short-listed entries of the microscopic world (Lira Gaysina’s image of Trichormus variabilis, shown in my earlier post, also demonstrates this tension.

Gunter_Forsterra_octopus_ga

Günter Forsterra: Octopus’ Garden (2015 winner)

Günter Forsterra’s winning image from 2015 illustrates another direction that images of algae can take.  He photographed marine macroalgae – several orders of magnitude larger than the microalgae discussed in the previous paragraph –but, like Petr Znachor and Lira Gaysina, he was not aiming to create a technically-perfect image that would allow a viewer to name the organisms present.  Instead, he takes us into another world, one that is hidden to all but a small number of initiates.   The temptation is to refer to the underwater landscape portrayed by Günter as “surreal”, but this term has a precise meaning in cultural studies (relating to the interface between dreams and reality) should not really be applied haphazardly.  I prefer to the term “other worlds”, recognising that his image conveys an impression of a different, altogether stranger, world than most of us have ever experienced.

Algae_&_art_overview

Conceptual diagram of the tensions inherent in algal photography.  Scientific illustrations, designed primarily to inform, sit at the top of the pyramid; moving away from straight representation towards either of the other corners creates images with greater aesthetic value but, perhaps, at the cost of information.

There are, in other words, at least two tensions that can work on an image of an alga to create an aesthetically-pleasing image; I’ve summarised these in the diagram above.   Chris Rieken’s image would lie close to the apex of the triangle, with “representation” predominant; Petr Znachor’s image would lie closer to the “abstraction” corner, whilst Günter Forsterra’s is in the opposite corner, “other worlds”.   All of the images that are submitted can fit onto this triangle somewhere; the question is how these tensions are balanced to raise a straightforward representation of an alga into an image that combines informative, technical and aesthetic properties and creates a work of art.

Neither “abstraction” nor “other worlds” are unambiguous concepts; both require an interaction with the viewer.   To someone familiar with freshwater algae, Petr Znachor’s image is clearly of desmids, and many will be able to identify the two genera that are present (Cosmarium and Staurastrum).   However, someone who knows little of algae will just see a collection of colours and shapes.  The boundary between representation and abstraction, in other words, is fluid; the viewer is never neutral and, for this reason, the legend becomes very important, providing a bridge between the image and the viewer.  In a similar way, Günter Forsterra’s image could appear, to the uninformed, to be something from a science fiction movie.  Again, the legend acts to locate the image firmly on Planet Earth and, hopefully, to raise awareness of the importance of algae to healthy marine ecosystems.

Bresnan_Chaetoceros_chaos

Eileen Bresnan: Chaetoceros chaos (2010 shortlist).  An example of a very abstract depiction of an alga.

Depiction of “other worlds” is harder for those of us who study the microscopic world, due to the problems associated with shallow depths of field (see “How to win the Hilda Canter-Lund competition”); microscopic images, as a result, tend towards “abstraction”.  However, it is not just the shallow depth of field that is an issue here: we also have to consider the disruption caused to a microscopic ecosystem caused by the sampling process, and then as it is teased apart, squashed onto a microscope slide and viewed at unnaturally high light intensities.   That is why I prefer to use paints to recreate the microscopic world in situ.  The results are, I know, partially the result of my imagination but, then again, everything that we view down a microscope is, to some extent, manipulated and artificial.

This post, and the previous one, have focussed less on how to take a great photograph than on what makes a great image.   I hope that it inspires you to go out and have a go.   We’ll come back to some of the technical issues in microphotography in a future post.

More about the Hilda Canter-Lund competition can be found here

Hilda Canter-Lund competition 2016 second prize winner

Petr_Znachor_compressed

A short while ago I wrote about Tiffany Stephens winning entry for the 2016 Hilda Canter-Lund prize.   Following that, the Council of the British Phycological Society agreed that a second prize, of equal value, would also be awarded, starting this year, which means that I am very pleased to announce that Petr Znachor’s image of summer phytoplankton from the Řìmov Rservoir in the Czech Republic will also be honoured by the society.

The rationale for the decision is that Hilda Canter-Lund was primarily a photographer of the microscopic world, yet five of the seven winners of the competition to date have either been of images of macroalgae or (in the case of the 2009 winner) a seascape in which an algal bloom is prominent.  I suspect that there are a number of reasons for this, but the greater technical challenges facing anyone who wishes to photograph the microscopic world plays a key role.  The first prize is awarded based on a vote by members of the BPS Council; the second prize, by contrast, will be awarded at the judge’s discretion, but for an image in a contrasting style.   This year, as Tiffany Stephens won with an image of the macroalga Durvillaea antarctica, the award goes to Petr Znachor but there is no reason why, in future years, a microalgal image may get the most votes, in which case a macroalgal image will get the other prize.

Petr’s image shows summer phytoplankton in the eutrophic Řìmov Rservoir dominated by the desmids Cosmarium and Staurastrum. It was taken during examination of a sample that was collected as part of a long-term monitoring program and concentrated with 20 µm plankton net.  He used an Olympus BX51 microscope with Nomarski contrast lighting and an Olympus DP70 camera.

znachy

Petr Znachor received his Ph.D. from the University of South Bohemia (Czech Republic) in 2003. He is currently a research associate at the Institute of Hydrobiology where his research focuses on phytoplankton ecology and, in particular, the ecology of reservoirs and analyses of long-term time series of data. Ever since he first looked through a microscope he was astonished by the myriad beautiful shapes and colours of phytoplankton existing in a single drop of water. He hopes that his pictures raise awareness of the importance of these tiny organisms.

As do we.

Hilda Canter-Lund competition 2016 winner

swell_life_Tiffany_Stephens

The winner of the 2016 Hilda Canter-Lund photography award is Tiffany Stephens, for her photograph “Swell Life”, showing algae in the intertidal zone of Snares Island, a small sub-Antarctic island, 200 kilometres south of New Zealand.  Tiffany took this photograph whilst studying for her PhD at the University of Otago with Chris Hepburn.

The picture’s genesis is in the spirit of Henri Cartier-Bresson’s “decisive moment”: Tiffany was on R.V. Polaris II, trying to collect data on the amount of particulate organic matter that was being released into the water by macroalgae, and the role that this played in food webs.    One day, when the sea was especially calm and the swell small, the skipper was able to bring the boat closer to the steep rock wall smothered with algae so that she could lower a probe into the water to collect a sample.   It was during this manoeuvre that Tiffany was able to snap the picture.   Closely cropped, the algae of the intertidal zone and the surging water create a semi-abstract composition that also tells a story of the functioning of near-shore communities in an inhospitable environment.

The dominant alga in the photograph is Durvillaea antarctica, “southern bull kelp”, a brown alga that is only found on exposed shores of the cooler regions of the southern hemisphere.   Above the Durvillaea there is a resilient band of mixed red and encrusting coralline algae.

Tiffany_Stephens

Tiffany Stephens, 2016 Hilda Canter-Lund award winner.

Unlike the fucoids, common on north temperate coasts, Durvillaea antarctica does not have air bladders in its fronds.  Instead, the interior tissues of the leathery blades have an unusual honeycomb structure which confer strength and buoyancy.   This also means that if the holdfast fails, the kelp is able to float, and to be transported around by oceanic currents.  This may help to explain why Durvillaea is so widespread in the southern hemisphere.  However, it is not just the kelp that benefits: these “rafts” of Durvillaea have been suggested as one means by which the sub-antarctic islands were recolonised by invertebrates following the last ice age.

Durvillaea is also eaten by coastal communities in some parts of the southern hemisphere and, bizarrely, used by Maori communities in New Zealand to preserve “mutton bird”, the sooty shearwater (Ardenna griseus).  If the honeycomb structure of Durvillaea is to function as a buoyancy aid for the living plant, the exterior tissues of the blades needs to be air-tight.  The Maori exploit this property, removing the inner honeycomb tissues to create air-tight bags.  They then preserve the young shearwater inside these bags, covered by their own fat (a sort of shearwater confit, I guess?).

One final fact about Durvillaea is that it forms part of a rather rude expression for sexual intercourse in Chile (remojar el cochayuyo – literally “soaking the seaweed”).  Don’t ever say that reading my blog doesn’t broaden your horizons …

Durvillaea_antarctica

Left: an underwater view of a “forest” of Durvillaea antarctica; right: the “honeycomb” tissues inside a frond of D. antarctica.  Photographs: Chris Hepburn, University of Otago.

References

Fraser, C.I., Nikula, R. & Waters, J.M. (2011).  Oceanic rafting by a coastal community.  Proceedings of the Royal Society Series B 278: 649-655.

Stephens T.A. & Hepburn C.H. (2014). Mass-transfer gradients across kelp beds influence Macrocystis pyrifera growth over small spatial scales. Marine Ecology Progress Series 515: 97–109.