Atlas of Life
Occasional Paper

Series 1, Number 1

A love affair with Martensia –
and some DNA for your diet?

by Roy Francis, Atlas contributor

April, 2018

 

This story spans nearly two years, but I'll try to keep it brief. In a way, it’s a satisfying blend of art and science, taking this hobby photographer from exquisite underwater discoveries into the rapidly emerging world of DNA analysis and its growing implications for citizen science. And it was virtually a love affair from the start, or at least an infatuation.
I'm sure you know the feeling.

In a shallow channel near Depot Beach in Murramarang National Park, I spotted a tiny, eerily beautiful marine plant. My wife, Jenny, and I were on our annual pilgrimage from Melbourne to the NSW south coast. The delicate shape, its striking iridescence and textured “leaves” (or thallus) of mesh struck me as something I had not seen the like of before. After taking a macro photo or two, a particular obsession of mine, I gave it little more thought.

Figure 1. Martensia sp., Batemans Marine Park, near Depot Beach. NSW

Figure 2. Martensia sp., Bittangabee Bay, Ben Boyd National Park. NSW

But some time later, I was snorkelling in an inter-tidal channel next to Bittangabee Bay when another tiny plant came floating by. It was similar to my first sighting, yet its multi-hued and gorgeous colours of purple and blue and yellow and red and green, all with that fabric-like texture, had me hooked. It was here I dubbed it: “the rainbow plant”. It looked a little bedraggled, so I decided it had probably been attached to rock at some stage, as had my first encounter, but was now being battered by the tides.

 A third meeting with a still more wondrous specimen a short time later near Pretty Beach also in Murramarang, convinced me I could contain my excitement no longer. What on earth was I looking at here? A major problem was that despite some background in science and bush regeneration, I knew next to nothing of marine botany.

Where to start?

Figure 3. Martensia sp., Batemans Marine Park, near Pretty Beach. NSW

So Parks NSW put me in touch with Libby of the Atlas of Life, who suggested Phycologist and Ecological Consultant with Elgin Associates, Nick Yee, might help with an ID. Nick suggested that based on my photo, a marine macro red algae, possibly Martensia australis (Division: Rhodophyta; Family Delesseriaceae), was a good candidate. However he recommended that I look further for confirmation. I confess I became pretty confused browsing some major references of this field as suggested by Libby and Nick.

Exchanges with Bob Baldock, a Phycologist with the State Herbarium of South Australia, then suggested - with cautions - that Martensia fragilis may be a better fit. The Herbarium’s resources here are second to none, based as they are on the inspirational “Marine Benthic Flora of Southern Australia” by the late Bryan Womersley and Bob’s Identification Factsheets. The taxonomic key that Bob offered did look compelling to my amateur’s eyes, and the Herbarium’s photos of microscopic structure were truly fascinating.

Figure 4. M. australis - sl 17251 dk fld (from SA Herbarium)

Bob’s cautions were twofold. Firstly, the genus has had a rocky history over the past 30 years, particularly with debate over the provenance of M. fragilis, and another possible candidate, M. elegans. Then, he suggested a dried specimen would be needed for microscopic examination of its reproductive features. I learned that southern Australia is home to some 800 species of red algae, and that identification can be very difficult without this. Fair enough, except that I assumed that specimens in a Marine Park would be protected, and therefore had kept nothing but my photos.

Bob thought that John Huisman, Curator of the WA Herbarium, could be the next logical step in my quest. John is Australia's foremost authority on marine algae, with over 35 years’ experience and 7 books to his credit. As luck would have it, we were about to visit Perth, and John agreed to a meet-up. He was most encouraging, but his views were as startling as they were informative. He believed M. australis may still be a candidate for my specimen. However, based on current international research (you can see an example here), and confirmed by his own recent personal experience, he thought nothing less than a full DNA analysis of a specimen would be needed for species determination. But, and this is where this story got really interesting, even this would not have settled things (assuming I had been able to produce a dried and pressed sample). The final stumbling block is that John says there is no DNA reference, no “type specimen” (also known as a barcode) of M. australis with which mine might have been compared. Was this game, set and match? Well, not quite, as it turned out.

I learned that W. H. Harvey discovered and named M. australis in King George Sound near Albany, around 150 years ago, so defining its “type location”. And we would be visiting Albany in a few weeks. So would we be interested in looking for a candidate type specimen? Well, yes actually! John seemed pretty chuffed, and equipped us with the necessary drying and pressing gear, and assured us any permits could be arranged.

On arriving in Albany, a local Ranger advised us on several likely coastal spots where we might look: snorkelling and simply exploring rocky intertidal areas were both possibilities. We spent a week exploring this convoluted yet really beautiful stretch of coastline, sadly, with no Martensia to show for it. So we reluctantly had to agree with John that we needed to settle on labelling our rainbow plant as simply: “Martensia sp.”, and leave it at that.

Your last visit to the local pharmacy might have reminded you how rapidly the science of DNA profiling has become commoditized as DNA Testing Kits, and is now a fascinating part of shaking the branches of your family tree. But what about its impact on botany?

According to John Huisman, my little story is indicative of a fast growing global challenge, and not just with algal taxonomy. Following a history of taxonomic confusion, DNA analysis must now become more entrenched as a taxonomist’s tool to help come to the rescue. Many more species will possibly come to light as a result. And reclassification will likely become much more prevalent in the world’s collections of voucher specimens.

What does all this mean for you as a citizen scientist or field naturalist? With what level of confidence can you now approach your favourite texts or websites with their images, descriptions and taxonomic keys? Must every identification now depend on DNA sequencing for comparison with a barcode? To the last question, I suggest no, and certainly not yet. Traditional methods should continue to at least get us close, and mostly it’s the best we can do. There are signs that in time, high-tech DIY DNA analysis (such as this device) could become accessible to citizen scientists, but don’t hold your breath.

How is this uncertainty reflected in the major references for the field of algae, such as the prestigious www.algaebase.org? The short answer is that it isn't, yet, possibly because it’s the best they can do in this rapidly changing field of knowledge. But I do find this disconcerting, because funding for progressing taxonomic work seems to be diminishing, particularly in algal areas.

Yet maybe this represents an opportunity for citizen scientists to provide leg work support to our nation’s Herbaria. Perhaps we can sometimes help by locating type specimens to become new DNA reference barcodes, just as Jenny & I were afforded an opportunity by John. So do seek support from an Atlas Moderator and perhaps your Herbarium whenever you have reason to suspect you have a classification issue of this nature, at least with macro algae. I am in no position to suggest just how many other families and genera are being impacted today, but I hope to get some handle on this in the coming months. I’d really appreciate hearing of any intelligence you might come across.

Figure 5. Jenny & Roy under Busselton Jetty. WA

Is this all a case of love's labour lost? Not a bit of it. For me at least, the naming of things is one part of a rich experience of discovery, wonderment and learning. And our attempts at classification can still prove most helpful along the way.


A huge thank you to Libby for all the encouragement, and to Nick, Bob and John for taking me this far. And see you on the coast sometime?



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