Most adventurous birthday

This year’s birthday was pretty special even though I didn’t get to spend it with any family members or close friends. We had an early breakfast and head out to Poza Azules, one of the ponds in the Cuatro Cienegas Valley. I get to go along this trip because two of the grad students in the team here, JR and JC, are monitoring the limnology and hydrology of the pond systems in the Cuatro Cienegas Valley. Poza Azules is named for its blue color. It is a decent sized pond but just one look at it will take your breath away. The blue color is due to carbonate precipitates of the high metal content in the area.

Poza Azules

It definitely made me wish we could swim in there. However, it is no longer open for swimming due to the negative human impact on the stromatolites (structural outcome of the interactions between microbes and chemicals in the water column). In the picture below, the stromatolites are the spherical looking sponges in the water. 

Stromatolites at Poza Azules

The plan for that morning was to sample only two sites but as we were driving towards the second pond, JR noticed that the GPS showed another site of interest, Poza Tio Candido, to be very close to us. As it was still pretty early, we decided to check it out. We parked by the path and walked according to the direction provided by the GPS. A first timer here, GPS coordinates are very important! A lot of the landscape looks very similar. If it weren’t for the mountains surrounding the valley, I would not have a good sense of where North is (the Sun is not always helpful because it stays right above us for a good part of the day).

As we walked to Tio Candido, I had an unfortunate encounter with a pile of old cactus. Throughout the entire trip, I wore my Teva flip-flops as we often had to get really close to the pond where the ground is muddy and we are likely to sink. It is easier to clean and wash off with flip-flops than when wearing sneakers. I was looking around the area as we were walking instead of looking down. All of a sudden I felt sharp pain on my foot and realized that I had stepped onto a pile of old cactus. JR had to remove my flip-flop and individually remove all the cactus torns that got stucked to my flip-flop while I balanced on JC as at that position, I was surrounded by cactus. Phew, lucky thing that it was old cactus and the torns were more brittle.  

Tio Candido

Unlike Poza Azules, Tio Candido has a completely different ecology. The vegetation around and in the pond is much denser. We also got to see some turtles and frogs on the lily pads. It is just amazing to see all these water bodies in the desert and each of them has their own unique ecology. 

The channel feeding into Tio Candido

After we sampled Tio Candido, we head towards the last sampling site for the day, Poza Escobedo. On the way there, we passed by a cattle ranch. The pond there looks completely different, like an oasis in the middle of the desert. The grass around the ranch definitely looks like it is well fertilized by the cattle. While the green grass looks really fresh in the desert, it just feels weird standing around it. It does not seem to fit in the desert. Furthermore, the pond is extremely green, which is worrisome because it can be polluting downstream water. 

The pond by the cattle ranch

The last pond for the day, Poza Escobedo, was named after a revolutionist, Escobedo. The fort that he had fought in still stands near the pond. 

Escobedo Fort

The fort is just a square building with an entrance and two windows. Poza Escobedo is formed from karstification, which is when the minerals dissolved and the ground is eroded, allowing the ground water to rise above the ground level. This pond also has high mineral content, causing the water to have a bluish color. However, unlike Poza Azules, Escobedo does not have all the stromatolites growing on the sediment. This makes the pond looks like a clear blue glass with the sediment so white and clean. 

Poza Escobedo

Clear water of Poza Escobedo

While these ponds are pretty far apart, some of the ponds in this valley are connected underground. Driving through the dessert, one often sees a water body that appears and then disappears underground. While the entire terrestrial ecosystem is pretty stable, the wetland ecosystem is not at all. Talking to the researchers in the group and also some of the conservationists in town, the water levels in the ponds and the structure of ponds can be highly variable. It is definitely a very fragile ecosystem. This is why it is had caught the interest of environmental organizations such as World Wildlife Fund and the Nature Conservancy.  

We travelled to all these ponds with the guide of a biologist from Pronatura, a local non-profit organization that is responsible for the conservations of various ecosystems in Mexico. His group had started a project to try to create a wetland to attract migratory birds to the valley. To do that, they created a dam at one of the river that runs in the valley. It was a great opportunity for us to look at some of the conservation projects that goes on in the valley. 

The river that was dammed.

The area in which the wetland will be created. 

It was an extremely hot and long day but definitely very educational and interesting.