Sunday, September 30, 2012

Visit to the Talek

This summer we have documented some of the worst water quality we have ever seen on the Talek River, in four years of monitoring, with dissolved oxygen (DO) levels at 40% in the middle of the day, and ammonium levels near 1 mg/L. It has been surprising to see the Talek in such poor condition, even after the relatively high rainfall and flows this season. We have long been interested in the Talek River, and in determining what portion of inputs are due to wildlife versus human sewage. One of Emma's major research interests is human effects on rivers, so we were eager to introduce her to the Talek River. During her and Pat's visit, we traveled from the upper to the lower reaches of the Talek to collect samples on changing water quality and pharmaceutical levels that could indicate the degree of human vs. wildlife impact on the river. 

Although we have sampled the middle and lower reaches of the Talek for years, we were incredibly grateful to be invited by the Director of the Mara Conservancy, Brian Heath, to visit the upper-most reaches of the Talek, which are inside the Naboisho Conservancy. He had told us how the river is in generally better condition up there, and we were excited for the opportunity to see it with him and hear his thoughts on the river, as he is such a source of knowledge about the area. As an added bonus, he flew us up there in his plane, covering what would have been about seven bumpy, dusty hours by road in about 10 minutes!

This was by far the smallest plane I have ever been in, and as a sufferer of motion sickness, I was a little nervous about the flight as we pushed the plane into position for take-off. However, it was a smooth and beautiful flight, it was amazing to see an aerial view of the Mara, and no motion sick bags were necessary.

Pushing the plane into position for take-off
Aerial view of the Mara River
We landed at the airstrip for the Naboisho Conservancy, where we were greeted by the Conservancy rangers and driven to a site on the upper Talek River. Naboisho is a relatively new conservancy, started in 2010, and it is located in a beautiful section of the Mara I had never seen before. The landscape was rolling hills of acacia shrubland, with beautiful open views and lots of wildlife. The location we visited in the upper Talek, near a Naboisho Ranger's Station, was on a lovely stretch of river, lined with smooth, water-shaped rocks. Although the river was quite low, we could see the debris left behind by a huge flood that came through just a few days before our visit. Despite the low water levels, the DO at this site was super-saturated with oxygen, at 130%, indicating high levels of in-stream productivity. 

The upper Talek inside Naboisho Conservancy
High water mark on the upper Talek
Our next stop was on a small tributary to the upper Talek, the Enesikiria. Here we visited the upper-most hippo pool in this area. This is a great location, because it allows us to investigate the first effects of hippos on the river, and we will likely re-visit it for more sampling in the future. This pool was mostly stagnant, with little water flowing through it, and we could see the impacts of rotting hippo feces on the bottom of the pool. The DO levels here were 1.6%.

Investigating a hippo pool on the Enesikiria tributary to the Talek 
This was a great visit, and it convinced us of two things: 1) we should spend more time studying the upper reaches of the Talek River, and 2) we really should buy an airplane to fly to our study sites. Asante sana to Brian for hosting us!

Emma and Pat in front of the plane
Continuing downstream on the Talek by road, we sampled the Talek above most of the lodges and above and below Talek town. We also had our first, and only!, breakdown of the trip, but fortunately it was a small puncture and easily fixed. DO levels remained fairly high along this stretch, 80-85%, likely due to the high flows that had just come through and flushed out the river. We also sampled another tributary of the Talek, the Olare Orok, at a place fittingly known as "Smelly Crossing." Here DO levels were 27.9%. Although there are a growing number of lodges on this river and its tributary, the Ntiakntiak, it also has the highest density of hippos in the Mara, according to a survey done in 2009 by Erustus Kanga. 

Breakdown on the Talek-Aitong road
Chris measuring water quality on the Olare Orok
So what causes the river to look and smell the way it does-- hippos or people? And how much impact does this small tributary have on the Talek, and the Mara? You can see here an impressively large hippo pool located at the confluence of the Olare Orok and the Talek, with 56 hippos in it, and the plume of dark water emanating from the Olare Orok.

Pool of 56 hippos at the confluence of Olare Orok and Talek Rivers
Finally, we reached our last sampling point on the Talek, just before it reaches the Mara River, at Rekero Camp. We have worked with the folks at Rekero Camp for several years now, and they have been incredibly gracious in hosting several of our meters and allowing us to sample the river there. Interestingly, the DO levels here were still quite high, at 84.7%, despite all the inputs coming in from upstream, likely due to the high flows that had just come through the river that week. This emphasizes the critical importance of having sufficient flow levels in a river-- given enough water, rivers have an abundance of natural processes that allow them to breakdown and incorporate a certain amount of inputs. However, when they are robbed of their most important resource, water quality suffers quickly.

Chris checking our depth logger in a Talek hippo pool
After all the traveling and sampling, we were very grateful to the folks at Rekero for inviting us to relax with a cold glass of mango juice. Now this is the way to wrap up a sampling trip!

Relaxing at Rekero Camp

Saturday, September 29, 2012

New Staff Gauges on the Mara

On our way back from the Mara Day celebrations, we stopped by the Emarti Bridge, near Olerai Farms, to show Emma and Pat one of our study sites. There we found a group of guys installing one of 17 new staff gauges being installed throughout the Mara River Basin in a joint effort by the Nile Basin Initiative's Mara River Basin Project and the Kenya and Tanzania water management authorities. 

Me and Emma with the fellows installing the gauging station
You can see in the pictures below the impressive infrastructure going into installing these stations. This pipe is being buried down to the water level in a ~15 m tall bank, and a float inside will automatically record the river level on a regular basis.

A gauging station being installed at Emarti Bridge

This is a tremendously exciting development for the basin, as it will allow the management authorities to better monitor the river's flow level and water extraction levels and to determine when the reserve flows (minimum flows which should be left in the river) are being impacted. I thought this was a perfect finale for Mara Day!

September 15 - Mara Day

"The Mara is one of the critical ecosystems in the Lake Victoria Basin that support sustainable socio-economic development and biodiversity conservation.

Recognising the importance of the Mara ecosystem, the 10th Sectoral Council of Ministers for Lake Victoria Basin, held in Kigali, Rwanda, in May this year declared every 15th September the “Mara Day” to coincide with the great migration of wildlife from Serengeti National Park in Tanzania to Maasai-Mara National Game Reserve in Kenya.  The celebrations shall be held on an annual rotational basis between Kenya and Tanzania."

This year, the inaugural Mara Day was held in Mulot, Kenya, at the new Resource Center of the Mara River Water Resource User's Association (MRWRUA)The celebrations were organised by the Lake Victoria Basin Commission (LVBC) and the County Councils of Bomet, Trans-Mara and Narok in Kenya, and were supported with funding from USAID - East Africa. 

Hundreds Attend First Mara Day Celebrations

I was impressed by the size of the event, with large tents erected, a mobile sound system, stalls set up by local organizations, and hundreds of attendees, including Ministers from Kenya and Tanzania and the Executive Secretary of the LVBC. 

Hundreds of people attending Mara Day in Mulot

The celebrations got underway with a parade through the town of Mulot, followed by singing and dancing performances by school children, representatives from both Maasai and Kalenjin tribes, and a spirited group of elders.

A group of elders performing at Mara Day
Then a number of speeches were given by representatives from WWF, the Nile Basin Initiative, LVBC, local governments and others, culminating with guest of honor, Chair of the East African Community Council of Ministers and Minister for East African Community in the Republic of Kenya, Hon. Musa Sirma.

The theme of the day was "Mara - Uhai Wetu" or "Mara - Our Life." It was really exciting and inspiring to see so many people gathered to celebrate a river and to recognize its central role in supporting life in the basin. Hopefully all of these sentiments will translate into positive action on the ground to support protection of the river and its catchment area.

For my mother...

My mom likes giraffes.  We captured one of them visiting our camp yesterday with our game camera.

I hid the game camera hidden around a bunch of leaves on a tree.  The giraffe was eating the leaves on the tree and saw the game camera so he went in for a closer look and sniffed it.  

Friday, September 28, 2012

Big Belly

Check out the big belly on this hippo...seen walking by our tent last evening...

Thursday, September 27, 2012

The Machini

One of the main reasons Emma came to the Mara this summer was to train us how to use a very cool piece of equipment she was willing to loan us for the field season. In scientific terms, it is called a Suitcase Flow Injection Analyzer for Colorimetric Analysis. In the field, it became known as "The Machini" (Swahili tends to end all words with a vowel, even those words appropriated from English).

Emma and The Machini
In the past, I have had to preserve all my water samples with sulfuric acid, store them throughout the field season, and then transport them out of the country for laboratory analysis of nutrient levels. Major drawbacks of this approach include, but are not limited to, the following: some nutrients, like ammonium and phosphate, are very sensitive to preservation methods and can change over time; water samples are fairly heavy and add a lot of weight to your luggage, thus the need to bribe friends and family to visit you and return carrying bags full of water; and all of your data is tied up in water samples that can't be analyzed until the end of the field season, which is scary for several reasons.

While working on a project studying ecosystem function of large rivers in the US, Emma and her colleagues had several of these machinis built so they could do real-time nutrient analysis in the field. As that project is winding up, she was incredibly gracious enough to loan us one for our work, and to test to the concept that these machinis could be used in even the most remote locations.

Running the machini took a bit of preparation and set-up. On our side this included sourcing in Kenya reagent-grade chemicals that couldn't be flown over due to airline restrictions, 40 gallons of ultra-pure water (a challenge in a country where drinking water can be hard to find), and about 10 glass volumetric flasks (which now makes me nervous every time I hear an elephant walking near the lab tent). On Emma's side, it required getting the machini up and running for three different nutrients, packing up a supply kit for every possible troubleshooting fix that may be needed for the next several months, and getting through airport security with a machini covered in detectable levels of nitrate (since, of course, that is one of the things we analyze with it).

It also required pre-filtering of all of my water samples through very fine filters, which Pat and Chris took on very graciously.

Pat and Chris pre-filtering water samples
But all of our efforts paid off when we started it up and smoothly (more or less) ran through nutrient analysis of all 150 water samples I had collected thus far. This is a really exciting step forward for our research, as we can analyze and interpret our data as we go, and make any necessary changes to our sampling regime. The coolest part is that we can use this really fancy piece of equipment in a tent in the middle of the Masai Mara. Asante sana Emma!

Running The Machini inside the lab tent

Wednesday, September 26, 2012


On Emma and Pat's first full day in the Mara, we had the incredibly opportunity to witness a wildebeest crossing that resulted in some success and some tragedy.

One of the focuses of my dissertation research is the occasional mass inputs of nutrients to the river caused by drownings of wildebeest during crossings. Although it is not uncommon for a few wildebeest to die in every crossing, occasionally a mass drowning event will claim the lives of hundreds or thousands of individuals. These drowning events may be due to high water levels, the size of the herd crossing, interference by tourist vehicles at the exit, or simply a bad decision about where to cross. These large drowning events have been noticed for years, and they have been studied by paleoecologists interested in their potential role in providing meat to early humans, but no one has really quantified how large these events can be and how these pulse inputs may affect the river ecosystem, which are the focuses of my research.

Although I have read about these drowning events and seen their aftermath, I had not actually witnessed one occur until this summer, and it helped me gain a better understanding of how these events can happen. However, seeing a number of carcasses piled up is completely different than actually witnessing hundreds of animals panicked and drowning, and it was a completely heart-wrenching experience.

We had driven to the hippo pool near the lower Mara Bridge (aka Purungat Bridge) to show Emma and Pat one of our focal hippo pools, and we saw several thousand wildebeest massed on the far side of the bank. As they tend to do before crossing the river, they were milling around anxiously, occasionally approaching the water and then quickly retreating, each one seeming to come forward to test its bravery and then getting cold hooves. Finally, one brave individual leapt into the river and started swimming across, and it was like a cork was popped, and the rest of the herd started flowing into the river.

Wildebeest crossing the Mara River

If they had crossed directly at the hippo pool, there would have been an easy path out. However, they seemed to be intimidated by the hippos and moved upstream a bit before crossing, and across the river from their point of entry was a fairly steep bank with only one narrow path up. As the herd continued crossing, frantically inspired by their need to follow one another and blind to the other side of the river, hundreds of individuals began piling up on the far side of the river. They either found themselves waiting in a long line to slog up an increasingly slippery path, perched on a low shelf with no path to the upper bank, or trying to keep themselves afloat in the deep waters of the pool.

Wildebeest unable to get out of the river

As more and more began massing in the water, we could start to hear their grunts and cries. Although they were a bit upstream from us and shielded from view, we could see through binoculars as they strained their nostrils above water. After several more minutes, we began to see their bodies float downstream. It was just a few at first, but they continued steadily, and in total we counted 483 carcasses. We estimated around 2,000 individuals had tried to cross, meaning nearly a quarter of this herd had perished in a single crossing event.

Wildebeest carcasses floating downstream

Some of the herd did eventually figure out that if they swam downstream a bit, they could exit easily through the hippo paths. However, the hippos became increasingly irritable at this invasion into their territory and aggressive towards the intruders. Several juvenile wildebeest were actually chased out of the pool onto the far bank several times, despite their repeated attempts to re-join the herd.

A hippo being aggressive toward a wildebeest
Hippos chasing a wildebeest out of the river
Anticipation of this aggressive behavior may have been one reasons the wildebeest didn't cross directly through the pool in the first place, despite the easier exit on the far side. Ultimately, these drowning events are likely caused by a confluence of factors. For example, at lower water levels, such as we saw in 2009, the wildebeest can simply stand on the river bottom while they sort out their exit path. Similarly, the effects of the drowning events on the river are influenced by a number of factors, which makes it important for us to study these rare events whenever they occur. Unfortunately, we weren't able to document any effects from this event, as almost all the carcasses floated directly into Tanzania, a macabre completion of the migration loop.

This was the third large drowning of the year. On Aug. 28-29, we estimate around 500 drowned several kilometers upstream of here. As we were counting those carcasses on Aug. 31, we witnessed another crossing at a bad location in which ~1,000 drowned. Including this most recent crossing, the total number of drownings for this season thus far is 2,000-- a drop in the bucket against a herd of 1.3 million, but a profound loss nonetheless.

You can watch a video Chris captured of much of the crossing here. The struggle against the far bank took place out of view upstream, but you can see some of the survivors emerging, too exhausted to feel triumphant, near the end of the video.

Karibu Mara Emma and Pat!

The past two weeks we were really fortunate to have two new visitors to the Mara. Emma Rosi-Marshall (middle) is a river ecologist and ecosystem ecologist at the Cary Institute of Ecosystem Studies, and she's on my doctoral research committee. Pat Charlebois (right) is an aquatic ecologist who works on invasive species for Illinois-Indiana Sea Grant. They came to help out with our research, get to know the Mara better, and bring over an exciting new piece of equipment and train us to use it (more on that later!).

As seems to be the norm for our guests, we stayed super busy throughout their visit-- driving across the whole middle portion of the basin, seeing all of our study sites and getting a lot of research done-- which made it difficult for me to keep up with the blog. However, I wanted to share some of the exciting things we saw and did over the past few weeks, so stay tuned for a few blog posts to come...

Tuesday, September 25, 2012

Sundowner with KT and David

One of my good friends and cohort-mates from the EEB department at Yale, KT Mertes, also conducts her doctoral research in Kenya. She studies spatial habitat use and movement patterns of birds at Mpala Research Center, near Nanyuki, and is interested in scaling up movement patterns to more accurately understand range distribution patterns. KT has been a huge help in making it through the first two years of grad school and developing my research proposal, so it was really exciting when she and her husband, David Schwartz, were able to come down and help out with our research for a few days. The first big wildebeest die-off of the season had just occurred, so we kept them busy during their two-day visit with carcass counts, water sample collection and a nutrient limitation experiment. However, we did find some time for a sundowner-- the lovely Kenyan tradition of toasting the sunset.

Friday, September 21, 2012

Failed Wildebeest Crossing

So... what does a failed wildebeest crossing look like?  Like this...

Most of the bodies were floating in the river next to the far bank.  Several hippos can be seen in the middle of the video.  

Wednesday, September 19, 2012

Game Camera

We are testing out a game camera in our camp that we'll eventually move over to a hippo pool.  Here are some of the highlights over the last week.

Tuesday, September 18, 2012