Post Lab at Work in the Mara

During my labmate JJ's visit, we built and deployed a fairly large experiment at three different study sites. The experiment was designed to determine what nutrients limit river productivity both above and below the effects of large wildlife. After sitting in the river for three weeks, we pulled the experiment out during my advisor David's visit. I doubt either of these guests knew how much work was in store for them in the Mara, but they were both incredibly gracious and helpful field assistants.

Here we are pulling the arrays out of the river. 

Each array had 60 cups with different types of nutrient additions and different substrates for algae to grow on. To my amazement, we only lost about 7 samples out of a total 180! Here is one of the cups with some algae visible. 

After we removed the substrates, we used several different techniques to determine how much algal and microbial activity there was on each substrate. Here's David measuring dissolved oxygen on the bank of the Mara with Paul and me.

Here's David... still measuring dissolved oxygen, now with Paul and Chris. It took about 8-10 hours to pull and analyze each array, so this resulted in a lot of time spent sitting on the riverbank.

After hours doing the experiment, we still had our routine sampling to do, including sampling macroinvertebrates and periphyton. 

David has done this kind of sampling in rivers and lakes around the world, so to have him help out with this work was really invaluable. I really appreciated how enthusiastic he was about collecting this data, despite the many, many hours we spent baking in the sun doing it. Thanks David!