Wednesday, January 26, 2011

End of Week 25 - Manatees in the Desert: La Presa Valsequillo, Puebla

The sun was glaring through the large pained-glass windows in the SEMARNAT office in Puebla. I had just returned from eating a large “comida corrida” at a nearby restaurant. As I sat at my desk overlooking the parking lot, waiting for a PowerPoint presentation to load, I watched other employees streaming out, leaving early in their government cars. I was exhausted; the kind of sleepiness that only eight hours in front of a computer, a heavy lunch in my stomach, and a Mexican afternoon sun can create.
I have been working to designate Lago Valsequillo, a large reservoir south of Puebla, as a Ramsar site, or a wetland of international importance. It’s the largest lake in the state and one of the only open lakes in the state during the winter dry season. When I talk about Lago Valsequillo as a Ramsar site, I usually describe it as a vast refuge for parched wildlife and a diverse oasis for increasingly rare flora and fauna. I highlight the huge flocks of migratory ducks that feed along its shores, the ospreys that pluck fish from its surface, and the ibises, herons and egrets that wade through its reeds. And I mention the recreation and tourism opportunities that can come with needed conservation efforts.
Lago Valsequillo and Puebla's volcanoes.















In contrast, I also discuss its problems. Lago Valsequillo is a seriously polluted, artificially created body of water. Factories from Tlaxcala and Puebla dump toxins into the lake’s river sources, turning them into oozing scars, thick and black with industrial sludge. The city’s non-existent sewage treatment system pumps thousands of gallons of raw sewage into the lake every day. Its waters are unfit for human use. If this were in New York State, the DEC’s fish advisory bulletin would say something blunt, like “Don’t Eat the Fish!”

Oil slicks on the surface of one of the lake's sources.



















The PowerPoint presentation that I was watching slowly open was about the contamination of the lake and strategies used to clean it. I scrolled through the slides quickly, searching for something about the lake’s wildlife. I saw a picture of what looked like a large hippopotamus and assumed that it was some comparison to a lake in another part of the world. In my groggy haze, I kept scrolling through the slides. But then I saw the image again; this time it was superimposed over map of Lago Valsequillo, with an arrow pointing to a cove on the southern shore. I studied the small, fuzzy photo a little closer. The excitement woke me up a little and I could see clearer now.  It was a manatee, on the shore, lying on its back dead, and surrounded by people, but it sure was a manatee.
The unfortunate manatee.
(from the original PowerPoint)
Could it be that there are manatees in Lago Valsequillo? Although Amazonian and West African Manatees do live in freshwater rivers, the West Indian Manatee, the species found in Mexico, does not. West Indian Manatees live in the warm, coastal, salty waters of the Caribbean Sea and Gulf of Mexico. Lago Valsequillo is eight hours and several mountain ranges from the coast. It is 2,000 meters above sea level, and is surrounded by very dry cactus forests and desert scrub. It is cold in Puebla, especially during the winter. Puebla has volcanoes, not coastal salt-water sea-grass lagoons.
Could they have swam up from the ocean in Oaxaca? No, that’s the Pacific coast, and it’s too far and the river is too shallow. Did they escape from the nearby Africam Lion Safari? No, they don’t have manatees at the Africam. A thousand thoughts raced through my head. I decided I had to ask Diego, Ana’s work counterpart.
“Diego, hay manati en Lago Valsequillo?” He turned from his desk and smiled, taking his eyeglasses off. I braced myself for the answer.
“Si…” He paused, waiting for a response. I was stunned. But… How could… Why would… They should… I mean, manatees live in…. I couldn’t think of what to say. Sensing my confusion, he explained. Lago Valsequillo has a species of water lily that efficiently absorbs 80% of the toxins that enter the lake. However, the lilies are invasive and cover more than half of the lake’s surface. They block out the sun, preventing other plant growth, and when they die, their decomposition sucks all of the oxygen out of the lake, killing the fish that the birds feed on. In the early 90s, the government and a group of scientists decided that they should introduce manatees into the lake to eat the lily and control its growth. It was an experiment with a somewhat predictable ending; needless to say, it didn’t work.
Lilies on covering the lake. (from the original PowerPoint)















In a sad twist, the manatees didn’t die from the cold, the lack of salt in the water, the high levels of pollution in the lake, or even from eating the heavy-metal laden lilies. Instead, when the impoverished farmers living around the lake saw the strange, one-ton creatures floating slowly along the surface of the water, they immediately knew what they had found: “monstros!” And naturally, their first reaction was to kill them.
As weird and unfortunate as this story is, I think I can use all of this to my advantage. Ramsar sites are all unique; they protect endangered species, are examples of rare ecosystems, and are internationally recognized for their ecological value. So let’s be honest; how many other freshwater lakes in the middle of Mexico’s high deserts can claim to have had manatees living there in the recent past? That must be hidden somewhere in at least one of the Ramsar designating criteria!
Lago Valsequillo from San Baltazar de Tetela.
White-faced Ibis on the lake.


Northern Shoveler on the lake.


Eared Grebe on the lake.


Blue-winged Teal on the lake.





2 comments:

  1. Thank you for posting this. Although it's sad to read about the pollution and invasive species, it’s wonderful to learn a bit more about the lake, which I have admired occasionally from the grounds of Africam!

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