The Rio Puerto Viejo runs through the La Selva Biological Station, in northeastern Costa Rica. For the past five years I have studied the fishes in a 1 km section of the river where it flows through the station.

La Selva Biological Station, Costa Rica

The La Selva Biological station is "the place to be" for tropical biology. A huge portion of what we know about the tropics was done at La Selva and it continues to be an active research station. La Selva is run by the Organization for Tropical Studies (OTS) also called the Organizacion Estudios Tropicales (OET). OTS is a consortium of 50+ universities in the United States and Central America. They maintain three field stations: La Selva, Las Cruces and Palo Verde, all in Costa Rica. La Selva is the flagship station. OTS owns the land at La Selva and maintains and protects it for research and education.

La Selva (which means "the forest") is located at the northeastern base of the central mountains in Costa Rica, approximately 1.5 hours by car from San Jose.

The La Selva property includes both primary and secondary (re-grown) rainforest, as well as swamps, streams, and two large rivers, the Rio Sarapiqui and the Rio Puerto Viejo. The Rio Puerto Viejo flows into the Rio Sarapiqui at La Selva.