17 Jan 2017
It was dark when we arrived last night, so we didn’t have a chance to really see the beautiful Finca SanPedro Hostel. The house has a number of nice rooms for guests and the grounds were beautifully planted and maintained. Chickens, peacocks, vegetable gardens, a yoga studio, and four friendly dogs all added to the charm.
Felipe Velasco, director of the Foundation Montecito, graciously agreed to take us to a small lake in the paramo above Lake Tota. Our goal was to assess the potential of the lake for sediment coring, and potentially collect more surface samples from the associated wetlands. However, before embarking on our trip we needed to purchase a few more supplies from a local hardware store in Sogamoso, including some PVC pipe and some wooden boards to secure our inflatable boats together for a coring platform. The folks at the hardware store were fantastic, providing supplies and assistance as we mounted the pipe and boards on top of our car. Furthermore, about half way through the process, they provided us with free coffee and delicious empanadas. And they gave us free hats and windbreakers with their logo! As Jason commented, “it is strange that the best empanadas I’ve had were from a hardware store.”
The drive to the paramo took about an hour and half, but along the way we got see Lake Tota and the town of Aquitania. Lake Tota is the largest natural lake in Colombia and lies at an elevation of about 10,000 feet. As we crossed into the lake’s watershed, we were immediately hit by the smell of onions. Most of the area around the lake and the surrounding hillslope is covered in onions; in fact, according to Felipe, the area produces more than 90% of the onions consumed in Colombia. The lake is also used for fish aquaculture, and along with fertilizer runoff from the onion farms, environmental degradation of the lake is of considerable concern. Apparently for every ton of chicken poop that comes in by truck, a ton of onions goes out.
Furthermore, the introduction of rainbow trout into Lake Tota likely led to considerable changes in food-web structure, and the extinction of a species of catfish, known as greasefish (Rhizosomichthys totae) that was endemic to the lake. An all to common story: invasive species + human impacts like eutrophication = extinction.
The town of Aquitania borders the lake, and we had to weave our way through it to reach a steep dirt road that led up into the paramo. A small town with obvious economic hardship, the central square of Aquitania is dominated by the church like in many of the small Colombian towns that we have seen. On top of the church is a large statue of Jesus standing on a boat, although because the boat is small it looks like Jesus is surfing. The road up into the paramo was in bad shape so we went slow, but we eventually arrived at the small lake that we hoped to reach.
Lake Aquitania, as we called it, was beautiful. Surrounded by paramo, including lots of frailejón (Espeletia sp.), the lake is bordered by extensive wetland in places. Several nearby depressions also contain wetlands. After inflating a boat, Jason and Jaime used a sonar depth finder to quickly determine the depth of the lake. Although the lake is relatively shallow throughout (~40 cm), there was over 7 meters of sediment! Mark, Jaime, and Jason spent a few hours collecting a surface core to carefully capture the mud-water interface, and I spent the time collecting surface samples from the adjacent wetlands. We then returned back to Sogamoso while Mark held the core upright, partially sticking out of the car window, and upon returning we extruded the core centimeter by centimeter into bags. Tomorrow we will return to collect the full sediment core, as well as additional surface samples from wetlands surrounding the lake.