By Pria Ghosh
Every year of my PhD, I pack up my bags and as much of the lab as I can carry and make my way to Potchefstroom, a town about two hours away from Johannesburg in the North West Province of South Africa. There, I settle down in the sunshine at North West University’s Potchefstroom Campus with the African Amphibian Conservation Research Group, run by Ché Weldon and Luis Du Preez. The benefit of this to me goes far beyond having a base from which can plan and carry out my fieldwork mapping chytrids across South Africa, but also in allowing a swap of the resources and expertise of our two labs.
My work in the Fisher Lab involves a huge amount of time at the lab bench, developing new molecular diagnostics for chytrids, DNA sequencing, and isolating and maintaining chytrid cultures. We all do quite a lot of fieldwork but, particularly in my case, trips have always been fairly short and often to totally new sites every time. We try to develop collaborations with field scientists who may or may not also be working on chytrid to collect samples for us on field trips they would be making anyway and so allow us to increase the geographical range of our samples at a low cost; it’s staggering how quickly fieldwork costs can rocket upwards! Although we all love fieldwork and jump at the chance to go whenever we can, our expertise and the resources we have available to us are primarily at the diagnostic and analysis end of things.
At North West University, they have the enviable position of being on the doorstep of some of the most wonderful field sites in the world, as well as some potentially fascinating Bd lineage ecology. Thanks to Ché and Luis’s years of experience, they have extensive knowledge of chytrid in Southern Africa, of how to navigate complex permit requirements, and an in depth understanding of the natural history and ecology of the field sites. All of this is invaluable to me and greatly speeds up the rate at which I can get my hands on useful data! Over the past two years I’ve carried out three major transects across South Africa to reveal the distribution of different Bd lineages across the country.
For my first transect (the Royal Natal Transect) I travelled from Mont-Aux-Sources plateau in the Drakensberg to the town of Memel in the Free State Province. I took what was essentially a straight line between Mont-Aux-Sources, an area I knew from Ché’s previous work to harbour BdCAPE, to Memel, where I knew BdGPL had been detected.
Mont-Aux-Sources plateau is at the top of the Drakensberg Mountains, and is the site of its highest point. Most of the plateau is the territory of Lesotho, but it’s accessible from South Africa. The route to the summit is a popular tourist hike despite having been recently listed as one of the most dangerous hikes in the world! It finishes with two eye-wateringly high chain ladders set in the rock face before you finally reach the plateau at over 3000m above sea level. The ladders are a serious challenge for a vertigo sufferer like me, especially as they are only attached at the top of the rock face so they swing and sway in the breeze as you cling on with a near enough 3000m mountain falling away behind you! Up here, the UV burns your skin even when it’s cloudy; there are no trees to provide shelter, although there is a simple but very much appreciated hikers hut to make use of; the weather can turn on you in an instant which is especially alarming when the fog descends. It’s also stunningly beautiful and gave me some of the most awe inspiring views I will ever see. Even more importantly for me, it has several cool, rocky streams which tumble over the plateau in huge waterfalls to form some of the major rivers of South Africa. All of them contain very isolated populations of Amietia hymenopus and have been studied by Ché and his students for years.
Several of the rivers from Mont-Aux-Sources route down into Royal Natal National Park. Forested areas matrix with wide open river valleys, rocky gorges and grassland. The Tughela enters Royal Natal National Park via a gigantic 947m high series of waterfalls (the second highest series of falls in the world). Here, the diversity of species increases with the range of habitats. Amietia delalandii are common, as are Hadramophryne natalensis (Natal Ghost Frog) tadpoles. True to form, I only once caught a glimpse of an adult ghost frog, and was nowhere near fast enough to catch it!
From Royal Natal National Park we travelled in as close to a straight line as we could manage to the town of Memel, stopping approximately every 30km to sample. Memel is a small town in a highly agricultural area. It’s also right next to Seekovlei Nature Reserve, a 30km2 area of RAMSAR wetland. We hope that there’s potential for a heavily agricultural landscape on the border of an ecologically pristine once could throw up some interesting chytrid dynamics!
The second transect (the Drakensberg transect) took me along the entire length of the Drakensberg. We started in the North at Didima, uKhahlamba-Drakensberg Park and travelled South, taking in Sani Pass (a challenge when towing a trailer) which leads to the Lesotho border and the highest pub in Africa. We travelled on through some stunning National Parks until we reached Garden Castle at the Southern tip of the Drakensberg mountain range. In two weeks we had all the weather the Drakensberg could throw at us from baking heat and intense sun (resulting in a lesson to always sun cream your ears) to torrential rain for days on end which managed to soak our tents and turn them into small paddling pools in the time it took us to put them up! We found nine species of amphibian with Amietia delalandii being the most abundant and widespread. Here, the rain was a help as it brought all of the Amietia out onto the road for us to collect as we drove by – no hiking required that night!
Finally, my third transect followed up some interesting work by an MSc student in Ché’s lab, Ruhan Verster. He has completed the mammoth task of surveying the entire length of the Orange River for Bd, from estuary to source through the semi-desert of the Northern Cape to the Drakensberg and the border of Lesotho. He has also experienced the benefits of collaboration. For two years now he’s visited us at St. Mary’s in London to do lab work and molecular diagnostics on his samples which are difficult to do in Potchefstroom. His results led us to realise that the dynamics of Bd along the Orange River looked very interesting, so we packed our bags and headed off to do a more detailed survey and attempt isolation. We started near Augrabies Falls, a 56m high waterfall in a 240m deep gigantic orange rocked canyon. Everything in this hot, dry environment depends on the green flow of the Orange River. It’s truly amazing how living things have eked out a niche for themselves in these brutal conditions – even tiny tadpoles sheltering in the shallow rock-pools right at the top of the falls! The Orange River is also the lifeblood of the communities through the Northern Cape, providing irrigation for extensive farmland on its banks and huge swathes of wonderful vineyards (the produce of which obviously had to be sampled!). The intense heat meant that most of our sampling was carried out after dark. Amietia delalandii were our principle target but we didn’t pass up the opportunity to sample any other amphibian that happened to cross our path!
On all of these trips I’ve been helped by students from the African Amphibian Conservation Research Group, and they have been totally amazing. Ryno Van Dyk, Allécia Boonzaaier, Ruhan Verster & Abigail Pretorius have introduced me to their study sites, helped logistically and made fieldwork so much smoother and more enjoyable. Ché Weldon has taken time out of teaching to join me on fieldwork, as has Trent Garner from the Zoological Society of London. After a particularly good Amphibian Conservation Research Symposium in Potchefstroom in 2016, Claudio Soto-Azat and Marconi Campos Cerquiera made a last minute decision to brave the chain ladders with me as well. This project has underlined for me how important engaging with other institutions and researchers is and the unexpected benefits and friendships it can bring.
The local expertise of researchers from North West University has sped up the fieldwork process hugely, and makes it much more enjoyable! In return they are able to take advantage of our specialism in diagnostics and genomic analyses to gain new insights into their study systems. The benefits of this collaboration to my PhD have been so extensive that I am now officially registered at both Imperial College London and also North West University. This required a fairly lengthy agreement process, but now means that I have the full support of two institutions that complement each other to complete my PhD. However, this cross continental collaboration is longer than one student cohort – it has been growing for years and is bearing fruit. It enables both groups to carry out so much more research than either could alone, saving time and money in the process. The sum of this collaboration is far greater than its parts, and long may it continue to be so!