Field trip to the Namib Desert – April 2021

The Namib Sand Sea

The Centre for Microbial Ecology and Genomics, where I currently work, has an annual trip to the Namib Desert for sampling purposes and, while it didn’t happen last year due to the COVID-19 pandemic, I was part of this year’s team. It was my first visit to both Namibia and the Namib Desert as well as my first field work since my SANBI internship many years ago.

Gobabeb and the Namib Desert

After flying in and spending one night in Walvis Bay, we were based at Gobabeb-Namib Research Station. It’s small research institution which has been running for several decades and hosts visitors from all over the world who wish to study the desert and its organisms. I found the accommodation there to be comfortable, the food tasty (and plentiful) and the staff very friendly. The only negative was the lack of a decent internet connection, meaning that I essentially spent my time there off the grid.

Gobabeb has a great position in the Namib where two very different landscapes meet. It sits on the bank of the Kuiseb river, which was dry while we were there, but which is marked by trees all along its length that are able to reach down to the water below ground. On the one side of the river are the gravel plains; huge, flat expanses with almost no vegetation or animal life to be seen. There is life, of course, but it mostly follows the rain and, while we did see some very brief rain, there was not enough to drastically change the desert’s appearance. The gravel plains also include Mirabib, a massive rock formation which was featured in the 1968 film, 2001: A Space Odyssey. On the other side of the river is the Namib Sand Sea where you will find massive sand dunes running along the coast where they receive most of their water from the regular coastal fogs. In fact, the combination of being a fog-influenced, coastal desert is so unique to the Namib Sand Sea that, in 2013, it was declared a UNESCO World Heritage Site.

We spent the evenings at Gobabeb but, during the day, we were mostly driving around the desert between various sampling sites. This was luckily not as bad as it could have been. Although it was hot outside (usually 30-35 degrees) and often quite windy, there was air conditioning in the car which meant we only experienced the harsh external conditions in short bursts. Night-time was actually harder because the buildings didn’t cool down as quickly as the outside air and it took a few nights before we had figured out the way to keep things comfortable. I learned two other things when we were driving around the desert. First, the dirt roads there are quite well-maintained and have fewer pot holes than the tarred roads in Pretoria! Second, Namibia (maybe exclusively) has salt roads along the coast, which would dissolve in a country that received any decent amount of rain.

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  The open expanse of the gravel plains

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  Sunset on the dunes

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  Looking out from Mirabib over the gravel plains

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  A view of Gobabeb from an observation tower showing birds and the sunset.

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  Sunset in Walvis Bay

Animals

Earlier I said that there was no animal life to be seen but that is not quite true. There are animals around but they are generally harder to spot and it depends on where you are (especially relative to any source of water). We saw various insects, sand snakes, a rather large caterpillar, which I believe was the larvae of some type of hawkmoth, and a herd of springbok which had probably escaped from a farm. Many of these encounters were obviously brief but some were a bit more memorable than others.

Two very nice animal encounters occurred at Gobabeb itself. The first concerned the pool, where we would go to cool off every evening when we got back. There were a number of rock martins (Ptyonoprogne fuligula) which would swoop down and fly along the surface of the pool to grab a drink. Even while we were in the water! We had no collisions with the birds but sometimes it was close. There was also a cape fox (Vulpes chama) which lived somewhere near Gobabeb and came into the camp a few nights while we were eating supper. It was adorable and a common enough sighting that the staff had named it Felix. However, the poor lighting conditions at night did not allow me to get a good photograph with my phone’s camera.

Scorpions fluoresce under UV light, making them fairly easy to spot, so I had made sure to bring a torch with a UV light function. Finding scorpions with UV light obviously needs to be done in the dark, so a couple of us from Pretoria, as well as a pair of entomologists from Belgium, went on a short night hike to find scorpions. I probably wouldn’t have spotted any scorpions by myself as my UV light was not really strong enough for such a task (the Belgians had a second and stronger UV light). In addition, I would’ve been looking in the wrong spot; we found small bark scorpions living on the side of a tree.

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  A snake camouflaged in the sand

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  Caterpillar

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  Scorpion fluorescing under UV light

The night hike had one other big problem, trees full of locusts! Admittedly, they won’t harm you, but no one wants a swarm of locusts going after them, especially in the dark. The problem was that the locusts were drawn to our torch light so, if we shone a light at a tree, there would be an intense rustling as the locusts began to stir and, eventually, start diving at the light. Not fun (at least not at the time). Luckily, they did not mind the UV light and, in the desert, you find that it is possible to see with the light from the moon and the stars.

The locusts were not the only frightening night-time encounter. Before we arrived, the Belgian pair had seen leopard tracks in the sand where they were doing their research and there was talk of a leopard sighting too, although I am not sure exactly when or where. The chances of actually encountering a leopard were incredibly remote but, nonetheless, I would occasionally check for eyeshine at night. Just in case. One night, as I was walking back to my room alone, idly checking for predators, I rounded the corner and heard a deep growl. I froze, looked around and started backing away as I saw a creature sitting on a chair in the darkness… Thankfully, it was not the leopard and it turned out to be an ordinary domestic dog which belonged to one of the staff workers that lived nearby. I had seen that it looked like a dog but I hadn’t hung around to get a closer look at the potentially-dangerous, growling creature. Instead, I went to get confirmation that it was just a dog and some backup to chase it away before I was finally able to get to sleep without further incident.

Science

While there was a lot of fun, sightseeing and socialising on the trip, the main purpose was science! There are many microorganisms (e.g. bacteria and fungi) which live in the desert soils and under rocks and which serve as our objects of study. Our scientific work fell under into three broad categories: fairy circles, soils and hypoliths.

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  A tree standing alone in the harsh desert

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  A welwitchia plant, only found in the Namib Desert

Fairy circles are an interesting phenomenon where grasses grow in a ring around empty soil containing dead plants. There can also be increased plant growth on the edge. There are lots of reports claiming to have solved the mystery of how they occur but it has still not been settled. The sampling we did on the fairy circles will form the basis of a PhD project for one of the members of our expedition and I’ve played a small supporting role.

I’ve been more involved with projects on the soil at different locations in the Namib. The lab has a collection of samples from across the Namib from various which has been used to start exploring the bacterial diversity as you move inland but there are still many, many unanswered questions. I was starting to look into some of them but, unfortunately, a lack of research funds has put most of that on hold. I will still be using some of the data, though, and a draft paper is in the works.

Perhaps the most interesting project, and what I will likely be working on for the rest of the year, are the hypoliths. These are microbial communities that form in deserts under semi-translucent rocks like quartz where they receive some protection from the harsh environment. In the photos, there is an example of a hypolith community growing under a quartz rock and looking very different from the otherwise-seemingly-lifeless, soil. There had been a little rain a few days before our visit, so the community was still active and you can see the green from abundant cyanobacteria.

Hypolith community under a quartz rock in the Namib Desert

Final words

All-in-all, the trip was a great experience both in terms of travel and science. It’s completely different to read about an environment and know it from text or even pictures versus actually travelling there and experiencing it. Now, I’ve got some good memories, better context of where my samples come from and many new samples to work on.

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