Rice, Pollution, and Crocodiles by Lucy Laws

We spent the first two months of our program in a typical tropical setting surrounded by luscious green plants and the short rainy showers usual for the dry season.  However, block three of our program took us to a whole new environmental extreme in a place known as Palo Verde National Park.   Palo Verde, also known as “dry, brown, and hot” (oh, and not to mention also the most mosquito-infested place we have visited to date), is a tropical dry forest, which greatly reminded me of the desert I call home in New Mexico.  However, this ecosystem presented us with many environmental issues that I didn’t think existed.

The first thing I learned while in Palo Verde was that there is quite a bit of land used for farming rice; rice, a grass that requires a great amount of water.  So how does a plant like this survive in such a dry environment?  Well the answer is simple: irrigation.  However, with irrigation come pests and with pests come pesticides and with pesticides comes pollution that eventually makes its way into the Tempisque River.  Now, the rice seemed to be growing fine with its irrigation and pesticides, but the river, which we later visited, did not seem to be holding up as well.  This river was a dark brown color and was full of sediments.  We also learned that the mangroves currently visible were nonexistent only years ago due to people chopping them down before they were protected.  But, the most alarming thing of all was seeing the animals that were living in this damaged ecosystem.

An American crocodile (Crocodylus acutus) sunning itself on the shore of the Tempisque River.

Aside from the many species of birds living in the mangroves, the health of the crocodiles struck me the most.  Researchers have recently identified that there are more male crocodiles than females, which can be attributed to several hypotheses.  One of the main causes is an increase in temperature.  But, a more shocking one is currently being studied: the potential relationship between certain pesticides and the sex of crocodiles.  However, no matter what the cause, the fact that there is a problem with the main predator in this ecosystem goes to show that something is happening here in Palo Verde that the public needs to become aware of.  Palo Verde may not seem like it requires a lot of maintenance, since many organisms die off during the dry season.  But, if we aren’t careful, those same plants and animals might not come back during the rainy season, or ever!