Oscar is a Tropical biologist, having graduated from the Universidad Nacional de Costa Rica, and worked as field biologist and researcher from 2009 to 2014. Since 2009, Oscar has also been the Reserve Science Director, in charge of the sea turtle conservation program in Tortuga beach. Thanks to this effort, the beach was declared officially as a nesting beach in 2014.
In regards to sea turtles, Oscar has written articles about nesting behavior and incubation temperature, and has participated in the International Symposiums of the International Sea Turtles Society on topics such as: incubation temperature in hatcheries (New Orleans 2014), nesting behavior of olive ridley (Dalaman,Turkey 2015) and foraging areas for hawksbill (Lima, Perú 2016).
Other research performed by Brenes include: Water quality studies; Mammal camera trap monitoring; River otter studies; Birds inventories; and since 2015 is currently conducting the investigation about Caiman and Crocodiles–capturing and tagging individuals to do a population estimation study and habitat preference of the different species.