Exploring the Magical Turquoise Waters of the Rio Celeste
December 5, 2023
The Magical Rio Celeste
Rio Celeste is a spectacular blue river (that’s right, blue) in Tenorio Volcano National Park of Costa Rica featuring a huge waterfall plummeting into a blue pool below.
The Rio Celeste is a truly breathtaking and mudderefic hike (meaning pretty damn muddy), and you’ll probably get rained on because you are in the rainforest after all. The trail is well-maintained and winds through a lush, tropical rainforest. Along the way, we encountered an abundance of flora and a set of tapir tracks.
How the Rio Celeste got Blue
Local folklore says Rio Celeste is blue because god dipped his paintbrush in the water after he got done painting the sky, and the paint was washed downstream.
The real story of the Rio Celeste and its turquoise blue color is a unique tale of chemistry and physics when two colorless rivers, the Río Buenavista and Quebrada Agria, merge into one another. The Río Buenavista carries a large concentration of aluminosilicate particles, while Quebrada Agria, as its name implies, has high levels of acidity and sulfur due to volcanic activity.
When these two streams mix to form the Celeste River, the drop in pH causes the aluminosilicate particles to aggregate and enlarge. These suspended particles produce what is called “Mie scattering” which gives the river its strong turquoise color.
Let’s get technical.
Río Buenavista (aluminosilicate particles = 184nm and pH = 6.8) + Quebrada Agria (pH = 3.1) = Rio Celeste (aluminosilicate particles = 570nm because pH = 5)
Cool beans? Are you not glad you took chemistry back in school?
The turquoise-blue color of the river is truly a sight to behold and makes for a spectacular and unforgettable hike experience.
Evolution and natural history of Baird's tapir
Baird’s tapir (Tapirus Bairdii) is a species of tapir that is native to Central and South America. It is one of four species of tapirs that belong to the genus Tapirus and is a part of the family Tapiridae.
Phylogenetically, tapirs are part of the order Perissodactyla, which also includes horses, rhinoceroses, and other extinct relatives. Fossil evidence suggests that the tapir lineage dates back to the Eocene period, around 55 million years ago, and has changed little over time. Tapirs have been found in fossil records in Europe, Asia, and North America, indicating a more widespread distribution in the past.
In terms of evolution, tapirs are considered to be “living fossils” because of their slow rate of evolution and close resemblance to their ancestral forms. Baird’s tapirs, like other tapir species, have short, stocky bodies, a flexible snout that they use to grasp vegetation, and large, hooved feet that are well-adapted for both terrestrial and aquatic environments.
Baird’s tapirs are herbivores and feed on a variety of vegetation, including leaves, shoots, stems, and fruits. They are solitary animals and are primarily active at night, although they may also be active during the day in areas with low human disturbance. They are excellent swimmers and can use their snout as a snorkel while crossing rivers.
Baird’s tapirs play an important role in forest health as they distribute seeds and fertilize the soil through their droppings, which can contribute to the growth of new plant life and support the overall health of Central American forests.
However, Baird’s tapirs are currently listed as vulnerable by the IUCN Red List due to habitat loss and hunting pressure. Conservation efforts, such as protected areas and anti-hunting laws, are underway to protect and preserve populations of this species.
Overall, Baird’s tapirs are a unique and fascinating species with a rich evolutionary history and an important role in maintaining the health of Central American forests.
Hiking along the Rio Celeste
As you continue on the trail, you’ll come across several small waterfalls, crystal-clear pools, and natural hot springs. The trail is not too strenuous, but you will need to climb over rocks and navigate through a few muddy areas, so make sure to wear appropriate footwear.
