A photo-essay of a recent field trip to Kenya’s portion of the East African Rift Valley.
* Originally posted on www.jamesorrphoto.com
For ten days at the beginning of November I went on a field trip to Kenya with a group of zoology, botany and environmental science students from Trinity College. The trip focused on ecology and conservation in Kenya’s portion of the East African Rift Valley but we were fortunate enough to learn a great deal about the earth sciences and socioeconomics of the area as well.
The African and Arabian plates are diverging and a 5,000km rift, the Great Rift Valley, has formed from the Middle East all the way down to Mozambique. In East Africa this rift valley splits in two, a western and an eastern portion. The eastern portion of the Great Rift Valley cuts right through Kenya and was the location of our field trip.
These rift valleys are places were the earth’s crust is splitting in two and the red-hot mantle is pushing towards the surface causing a huge amount of geothermal activity. Volcanoes and hot springs are common sites in this part of the world.
All of this creates energy that is harvested in geothermal power plants. In fact, 40% of Kenya’s energy comes from geothermal energy and we were lucky enough to visit one of these power plants during our trip (but that is a story for another blog).
This image is taken from the top of one side of the rift valley looking down at the floor of the valley and then onwards to Mount Elgon, an ancient volcano, which stands at 4,300m above sea level.
When it rains on Mount Elgon the runoff rushes down towards Hell’s Gate National park and over geological time this has created a deep gorge.
Each of the lines shows the water level at a certain time in the past. This scar in the earth’s surface has been getting deeper and deeper over a relatively short period of time. Some of the markings on the wall show dates, about 1/3rd of the way up this photo was the level the depth of the gorge ten years ago.
We visited Hell’s Gate during the dry season and so we were able to walk along the floor of the gorge and appreciate the beautiful curves and patterns in the rock.
Strangely, there has been a rapid increase in the water level of the rift valley lakes in the past decade. For example, in Lake Baringo, over a three- year period the lake area rose from 140kmsq to 230kmsq, an increase of 60%. This rise in water level has had many ecological and socioeconomic impacts but one of the most obvious ones is what has happened to the trees that used to border the lake.
The trees have become waterlogged and have basically drowned. Their skeletons are left eerily standing in the lakes.
Another effect that this rise in water level has had is a neutralisation of the water pH. More water dilutes the lake and so pH (and salinity) are neutralised. This has had many knock-on effects but one of the most dramatic things to have happened is the disappearance of some of the lake’s flamingo populations. Lesser flamingos feed on a genus of blue-green algae called Spirulina, which only grows in alkaline/basic conditions. With rising water levels and consequently more neutral pH levels this blue-green algae doesn’t have the right conditions to grow and the flamingos have no food. Lake Baringo and Lake Nakuru were two of the lakes we visited that had recently lost their world famous flamingos that used to come in their millions and attract tourists from around the world.
No one is really sure about what is causing this rise in water level. Climate change and deforestation in the catchment area have been put forward as possible causes.
The remains of a riparian forest, drowned tree skeletons and floating logs are all that is left. This photo is a long exposure of about 15 seconds and while I was waiting for it to finish taking I realised that one of the floating logs about 3m away (just out of shot) wasn’t a log at all, it was a Nile crocodile! Luckily it wasn’t a man-eater. Apparently it was too small.. it was only 2m long.
The amount of species we came across was astonishing. Lake Baringo for example has about the same number of bird species as Ireland. On a quick ten minute stroll around our campsite by the lake you might see fifteen or twenty different birds and you’d hear another 10.
We saw many of Africa’s classic safari animals like zebra, rhino, giraffe, hippo and about a thousand species of antelope. Buffalo and flamingo are seen gathering at the waters edge in the image above. But we also came across some smaller, less renowned animals that were just as fascinating. One of the coolest things we saw were the fireflies.
This is a three-minute exposure composite. It was taken well after midnight. The light comes from a full moon, which lit up the scene, from the shining stars billions of miles away and from the fireflies flickering around the shoreline. As they floated around looking for food or for mates they emitted short little flashes of warm yellow light every second or so. I wanted to stay for longer to build up the light trails from their flashes but a gigantic splash and a grotesque grunt quickly sent me on my way. I didn’t want to be by the waters edge when the hippos decided to come to shore.
I’m drawn to the eyes of this incredible beast every time I look at this photo. The image was taken moments after an encounter with a pair of spotted hyenas. The lion is about as majestic and powerful as the animal kingdom gets but its eyes reveal a vulnerability.
This vulnerability was to be seen everywhere we looked during the field trip. The East African Rift Valley ecosystem is delicate and if the destructive pressures of habitat loss, invasive alien species and climate change overwhelm it then maybe the incredible landscapes and remarkable wildlife that we experienced may not be around for long.
* Originally posted on www.jamesorrphoto.com