The scientific expedition Identity Madidi, led by WCS, conducted biodiversity surveys in 15 study sites, between 2015 and 2017, generating a significant amount of information on species diversity, population distribution and ecological knowledge. The registration of 1,400 new species of plants, butterflies and vertebrates increased the number of Madidi species to 1,888 (34% of the list of species registered before the expedition), confirming that it is one of the most biodiverse protected areas in the world.
Since 2018, Wildlife Conservation Society Bolivia Program, in collaboration with the program of the Joint Laboratory for Research on Evolution and Domestication of the Amazonian Ichthyofauna (LMI EDIA) of the French Institut de Recherche pour le Developpement (IRD), has been collecting water samples for environmental DNA analysis (eDNA) in water bodies in order to increase the number of species records, more importantly for cryptic species, and to better understand their geographical distribution.
The analysis is based on the detection of fragments of DNA molecules suspended in water, which are excreted by living organisms as feces and secretions, or decomposed organic matter. These DNA fragments are possible to detect in infinitesimal quantities by means of new analytical methods referred to as “Next Generation Sequencing (NGS)”, that consists on the application of the metabarcoding technique. This technique consists in assigning molecular bar codes to DNA fragments of the different species. In order to collect the DNA, special filters are used for which tens of liters are pumped at various points in the water body being sampled, which concentrate the DNA for further analysis in the laboratory. To identify the species or taxa present, reference databases are used, that have been developed in close collaboration between geneticists and taxonomists.
Preliminary results of the analysis show a great diversity of organisms that had not been registered before. We expect to have the final results by the end of 2020. Environmental DNA analysis will allow us to add new records to the current lists of species, have a reference baseline and better understand the biogeography and ecology of the different species. New research sites will also be prioritized in the framework of efforts to conserve biodiversity in Madidi.