Amgueddfa Blog: Blog

Recently working through the John Dillwyn Llewelyn collection, I was reminded of this amazing photograph of Swansea taken in 1858. The image was taken on the 15 March 1858 at 1 o'clock with an exposure of 15 minutes. It was taken by Welsh photographer John Dillwyn Llewelyn using a ground breaking process invented by him in 1856 called the Oxymel process. This was a development of the wet collodion process and used a solution of acetic acid, water & honey to preserve images. This meant that glass negatives could be prepared in advance and exposed in the camera as required, and produced a dry plate that could be kept for days. This new process meant landscape photographers no longer needed to carry with them portable laboratories and darkroom tents.

The photograph shows Swansea taken from St. Thomas on the 15 March 1858. To the far left, above the roofline, Mumbles Head can just about be made out. In the background (slightly to the right) can be seen the North Dock with buildings around it, and sailing ships in the dock. In front of that is the railway embankment alongside the New Cut of the river Tawe. In the foreground can be seen a number of houses, including the 'White Lion Inn', and to the far right it is just about possible to make out the remains of Swansea Castle.

I thought that it would be interesting to try and identify the viewpoint from where this photograph was taken and to see how the view might have changed since 1858. I therefore contacted my colleague Andrew Deathe at the National Waterfront Museum, Swansea to see if his knowledge of the area would allow him to identify the viewpoint.

Living locally Andrew was able to take this modern view in May 2015. He took the photograph by standing on the road which is in the foreground of the 1858 image, which is called Bay View, in St. Thomas. The house in the original image is just behind his viewpoint. John Dillwyn Llewelyn seemed to be standing half way between Bay View and Windmill Terrace (which wasn't built for another 20 years).

The skyline of Swansea has seen many changes over the years and it is difficult to tell that the two images are taken from the same viewpoint. However it is still possible to make out Mumbles Head to the left and part of Swansea Castle to the right. The railway embankment has been completely removed, and there is no trace or it or the tunnel today. In place of the old North Dock buildings, you can see the glass pyramid of Plantasia. The tower of St. Mary's church can't be seen unfortunately, as it is behind the BT Tower.

Mark Etheridge
Curator: Industry & Transport
Follow us on Twitter - @IndustryACNMW

Deep beneath the ocean surface, where no sunlight can penetrate, there are areas so hot, volatile and toxic that it's hard to believe life can exist...but it does, and often in abundance. It is exactly this kind of hostile environment that one of our most recent natural history acquisitions came from, a spectacular marine snail called the 'scaly-foot gastropod', or for those of you who like Greek and Latin, Chrysomallon squamiferum Chen, Linse, Copley & Rogers, 2015 (fig. 1). It comes from depths of 2785m, living on the edge of hydrothermal vents and black smokers that reach temperatures of 300-400°C. This is certainly not your average snail...

Under armour and ready for battle

It was in 2000 that the first hydrothermal vent field was discovered in the Indian Ocean, known as Kairei field, and a year on that Woods Hole surveyed the area in the RV Knorr 162-13 and encountered this new species. It was immediately obvious that something unique had been discovered. The 'foot' of this snail, which is the fleshy soft part that snails move around on, displayed hundreds of hardened tags, almost like an armour. These tags are called sclerites; fleshy in the centre and hard on the exterior due to a layer of conchiolin (a protein secreted as a part of shell formation) covered by a layer of iron sulphide that gives it a black metallic appearance (fig. 2). The iron sulphide exists in two forms in the snail: greigite, which is highly magnetic, and pyrite, which is commonly known as fool's gold. The presence of the metallic sclerites is not totally understood but Suzuki et al. at the Extremobiosphere Research Center in Japan suggest the snail may control the mineralization of the iron sulphides for protection from crab predation or perhaps for detoxification purposes.

Completely unique is that the iron sulphide is also found in the snails' shell, so this was the first discovery of an animal with iron sulphide in its skeleton (fig. 3). Underneath the metallic exterior there is a thick but softer organic layer which covers the hard calcium carbonate shell that most marine snails have. So unusual is this triple layering in the shell, in both its chemical make-up and mechanism, that some scientists consider it to offer extensive protection and think it may be used as inspiration for man-made armour in the future.

New vent fields, new discoveries

The iron and sulphide found in the scaly-foot gastropods at the Kairei field comes from the mineral rich waters expelled from the hydrothermal vents and black smokers. Different vents do, however, have different mineral compositions. Nevertheless, it was still of great surprise when in 2009 the Solitaire field was discovered in the Indian Ocean and living on it was a different colour form of the scaly-foot gastropod; this time displaying a brown shell and cream coloured sclerites, both completely lacking the iron sulphide coating. Genetic testing by Nakamura et al. at the Precambrian Ecosystem Laboratory in Japan confirmed in 2012 that they are the same species and also that the sclerites of the iron-lacking form were in fact mechanically stronger. Then, in 2011, yet another population of the black scaly-foot gastropod was found in great abundance at the Longqi field, another new discovery for the Indian Ocean, and this is where the two specimens deposited at this museum came from. Figure 4 shows snails from the three different vent populations.

The heart of a dragon

The external features of this snail are certainly spectacular and strange, but taking a look inside shows that the theme continues there. It is of no surprise that this snail has special adaptations to live in such a toxic and harsh environment; survival in such a place certainly requires an evolutionary helping hand. Similarly to other species living on black smokers and close to vent effluents it has evolved a symbiotic relationship with bacteria living inside its body. These bacteria supply the snail with most of its nutrition and to accommodate them the snail has developed a massive oesophageal gland, taking up over 9% of its body mass! In turn the snail needs to keep the bacteria alive and so has also developed a huge circulatory system, including a supersized heart, to supply the oesophageal gland with enough oxygen. It's a win-win situation, or perhaps a deal made in Hell!

What's in a name?

Although it was discovered 14 years ago it is only this year that the scaly-foot gastropod was officially christened Chrysomallon squamiferum by Chong Chen of Oxford University and his associates. This snail is so different to any others known that Chen et al. needed to describe a new genus to put this new species in. The genus name Chrysomallon means 'golden fleece', giving reference to the metallic coating often containing fool's gold. The species name squamiferum means 'scale-bearing', making obvious reference to the sclerites covering the foot of the snail. The process of describing new species also means that a specimen (holotype) or a series of specimens (holotype and paratypes) need to be selected as representatives of the species and placed in museum collections, and that is where we come in! The two specimens we have been donated are a part of this incredibly important 'type' series. They even came with a note telling us to store them in 100% alcohol as any water in the preservative would cause them to rust over time. Rusting is certainly not a conservation issue we usually have to consider with our mollusc collections!

Back at the museum

This is not the first addition of molluscs from deep sea hydrothermal vents to our collections. With resident bivalve researchers working here we already house material that has been described by our experts from such environments, in addition to other extreme marine environments. Some are from the oil seeps off Louisiana in the Gulf of Mexico, the mud volcanoes in the Gulf of Cadiz or methane seeps off Chile. Others are from hydrothermal vents on the Northern Mid-Atlantic Ridge and hydrothermal springs in the Cascadia Basin of the NE Pacific. Perhaps the strangest place that one of our new species was described from was the wreck of the sunken ship Francois Vieljeux which contained organic cargo containing sacks of beans, sunflower seeds and bales of sisal twine. Over time the rotting cargo produced a sulphur rich environment that attracted animals able to exploit it, including the bivalve Spinaxinus sentosus Oliver & Holmes (fig. 5). Amazing.

When you think that only 160 years ago much of the scientific community embraced Edward Forbe's 'azoic theory', that life could not exist beyond 550m, our knowledge and understanding of the sea has really come on a very long way. Nevertheless, there will always be more waiting to be discovered.

If you want to learn more about our collections follow us on Twitter @CardiffCurator

References:

Chen, C., Copley, J. T., Linse, K., Rogers, A. D. and Sigwart, J. (2014). Abstract from Seventh Congress of the European Malacological Societies. Edited by White, T. S.

Chen, C., Linse, K., Copley, J. T. and Rogers, A. D. (2015). The 'scaly-foot gastropod': a new genus and species of hydrothermal vent-endemic gastropod (Neomphalina: Peltospiridae) from the Indian Ocean. Journal of Molluscan Studies. 81(3): 1-13. doi:10.1093/mollus/eyv013

Nakamura, K, Watanabe, H, Miyazaki, J, Takai, K, Kawagucci, S, et al. (2012). Discovery of New Hydrothermal Activity and Chemosynthetic Fauna on the Central Indian Ridge at 18u-20uS. PLoS ONE 7(3): e32965. doi:10.1371/journal.pone.0032965

Oliver, P. G. & Holmes, A. M. (2006). New species of Thyasiridae (Bivalvia) from chemosynthetic communities in the Atlantic Ocean. Journal of Conchology. 39(2): 175-183; figs 1-32.

Suzuki, Y. et al. (2006). Sclerite formation in the hydrothermal-vent 'scaly-foot' gastropod - possible control of iron sulphide biomineralization by the animal. Earth and Planetary Science Letters 242. 39-50.

Yao, H. et al. (2010). Protection mechanisms of the iron-plated armor of a deep-sea hydrothermal vent gastropod. Proceedings of the National Academy of Sciences 107.3 (2010): 987-992. http://dx.doi.org/10.1073/pnas.0912988107

Every week we tweet about molluscs on #MolluscMonday via our @CardiffCurator Twitter account. This is a great opportunity for us to showcase some of the amazing specimens in our collections at the Natural Sciences Department of National Museum Cardiff. We also talk about some of the research work we do and highlight some of the fantastic molluscs that are out there.

So why not find out what we have been tweeting about over the last few months in our latest Storify Story 'Stunning Shells'.

If you find these interesting you can also follow us on Twitter.

And why not follow our Natural History conservators as well @NatHistConserve

Our second event on preservation of heritage in times of conflict is on Saturday 11th July at National Museum Cardiff, 10:00 to 17:00. Throughout the afternoon, we will again offer a series of short (15-minute) informative talks:

14:00 - Stabilizing heritage in turbulent times; what can science do? (Dr Lisa Mol, Cardiff University)

14:30 - The role of Conservators in heritage preservation. (Dr Christian Baars, Amgueddfa Cymru) 

15:00 - Authenticity, ownership and the question of restoration vs preservation vs conservation. (Jane Henderson, Cardiff University)

15:30 - Flint in Egyptian Pharaonic Warfare. (Carolyn Graves-Brown, Egypt Centre Swansea)

16:00 - War damaged monuments: memory and preservation. (Dr Toby Thacker, Cardiff University)

All talks are free of charge. The event is hosted by Amgueddfa Cymru and sponsored by Cardiff University. For further information follow our blog here, or at Cardiff University.

Museum conservators are responsible for the care of collections. This includes appropriate storage of objects, housekeeping, and maintaining the correct environmental conditions to stop, for example, books in library collections from getting mouldy. In addition, emergency preparedness is another aspect of collections care (or: preventive conservation). How important this is was recently demonstrated during a large fire that gutted an entire historic property.

The fire at Clandon Park in April 2015 was devastating. However, a large part of the objects on display in the house were rescued successfully. This was only possible because the National Trust, who owns Clandon Park, has in place extremely well organised emergency plans. When the fire broke out these plans kicked into action immediately, and a well-rehearsed cooperation with the fire service led to the salvage of hundreds of objects from the house.

The fire fighters risked their lives to salvage important cultural objects. In addition, the help from staff, volunteers and local people must not be forgotten. But the point I am trying to make is that without an emergency plan, all of those helpers may not have achieved very much.

The documentation handed over to the emergency services in case of a disaster in a historic property or museum includes information on what the most important objects are, where they are kept and how they are secured. This enables planning a salvage operation down to taking the tools required for object removal into the building; it avoids the situation where you stand in a burning room in front of the object that needs to be removed quickly only to find out you took a flat-head screwdriver, rather than the Phillips you actually needed.

Emergencies are not restricted to fires. Floods, storms, even earthquakes and acts of terrorism (for example, the attack on the Bardot, Tunisia’s National Museum) can all lead to cultural heritage being damaged. In Wales, the Assembly Government has set up an Emergency Planning Network for museums to help museums, archives and libraries prepare for emergencies. The development of a network response group provides heritage professionals to help museums, archives and libraries in the event of an emergency, and assist with salvage and recovery.

Amgueddfa Cymru – National Museum Wales has its own emergency plans which we hope will never have to be used – but it is nevertheless important to be prepared. Disaster preparation is part of the role of preventive conservators; we attempt to limit damage occurring to cultural objects in our care to keep them safe for you and future generations. This involves risk assessments, minimising risks – and being prepared for the worst to happen.

If you would like to know more about disaster prevention in museums, and heritage preservation in general, follow our blog, or Cardiff University's “Heritage in Turbulent Times” blog, and come to our free event at National Museum Cardiff on 11th July with talks on why scientists shoot with guns at building stones, restoration/preservation/conservation, flint in Egyptian Pharaonic warfare, and war-damaged monuments.

"Heritage in Turbulent Times" is a joint project between Cardiff University and Amgueddfa Cymru - National Museum Wales.