Voters in Ecuador cast ballots in favor of a referendum that would be future oil drilling in a national park inside the Amazon. So-called Block 43 accounted for more than 10% of the nation’s total oil production. File Photo by Rogerio Florentino/EPA-EFE

The referendum asked if voters agreed with a government decision to leave the oil in so-called Block 43 “indefinitely” in the ground. A result of some 20 years of advocacy, the report said the vote was cast in favor of the true wealth of Ecuador — it’s biodiversity, not its oil.

The vote came weeks after eight countries in South America — Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname and Venezuela — signed a joint declaration to end deforestation along the Amazon River.

The pact calls for each nation to enact environmental laws that seek to promote cultural diversity, gender and racial equality, and to strengthen and promote dialogue between governments and indigenous populations in the Amazon region.

Block 43 was considered among the largest in the country, representing about 15% of the country’s total oil production. The block hosts the broader Ishpingo-Tambococha-Tiputini oil fields, which are located in the protected Yasuni reserve.

Leaving the oil alone could strike an economic blow to a country already reeling from recent political violence. Apart from the referendum on the Amazon, voters in Ecuador tried to decide on their next president on Sunday.

A runoff is next between leftist Luisa Gonzales and Christian Zurita, whose name appeared on the ballot only after the assassination of candidate Fernando Villavicencio earlier this month. With its overwhelming Catholic majority, Pope Francis had condemned the “unjustifiable violence” in Ecuador.