Lake Tanganyika, Africa
In 34 days I will be stepping on a plane to Africa. Lightweight clothes, sunscreen, science books & relevant articles, camera, journal, malaria pills, and a really big hat ... I can't wait.
I've been thinking some more about my Nyanza project, and I may end up focusing more on the effects of deforestation than on climate change (although I suspect the two are, inevitably, related). Over the past 200 years, the northern part of Lake Tanganyika has been almost completely deforested. Runoff and erosion have increased, dumping sediment and excess nutrients into the lake. Since fish from Tanganyika supply almost half of the local population's protein needs, everyone is very concerned about lake health and productivity.
We will probably measure organic matter abundance over time to reconstruct productivity history, and look at sediment samples under a microscope to see how its composition and mineralogy change. Shifts in mineralogy can sometimes indicate a change in sediment source, and could help us understand how deforestation has altered erosion and transport in the region.
Fish depend on phytoplankton and other organisms in the water column, who in turn are strongly affected by sunlight and nutrient supply. Erosion can impact both: large amounts of fine-grained material can cloud lake waters, decreasing light penetration, and nitrogen and phosphorus washed from land (especially farmland) can cause algae blooms, etc. If we can compare changes in lake productivity and sediment type with the region's deforestation history over the past 200 years, then we might be better able to understand the relationship between land use change and lake health.