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First regional freshwater dolphin survey underway in South America

Posted on May, 09 2006

South American scientists are about to embark on an expedition through the rivers and watersheds of the Amazon and Orinoco Rivers to survey freshwater dolphins.

Santiago de Cali, Colombia — South American scientists are about to embark on an expedition through the Amazon and Orinoco Rivers to survey freshwater dolphins.

The expedition, which consists of scientists from Colombia, Peru, Ecuador, Bolivia and Venezuela, will start in the Venezuelan city of Ciudad Bolivar and continue 1,730km to Puerto Carreño in Colombia.

"Freshwater dolphins are one of the most endangered mammals in the world," explained Fernando Trujillo, Director of Fundación Omacha, one of the organizations leading the expedition, with support from WWF, the Wildlife Conservation Society, Fundación La Salle and the Whale and Dolphin Conservation Society.

"Mercury contamination, deforestation, indiscriminate capture and incidental fishing are some of the factors affecting the species. Currently we don’t have abundant populations and this census will allow us to gather data in order to design a management and monitoring plan as well as get to know the state of the watersheds of the Amazon and Orinoco Rivers."

This is the first dolphin counting initiative in South America and it follows similar counts in Asia where WWF has financed research expeditions in India, Pakistan and Bangladesh. The idea is to establish how many river dolphins there are in the Amazon and Orinoco in order to set up specific conservation strategies. The census is also part of a training programme for South American scientists in estimating numbers of threatened species.

"Supporting this census is important for WWF since the conservation of the pink river dolphin is a good indicator of the ecological health of these river basins," explained Saulo Usma, WWF Colombia’s Freshwater Coordinator. "Being a regional initiative, the information gathered will help achieve the conservation goals of our global freshwater and species programmes."

The pink river dolphin (Inia geoffrensis), also known as the boto, is found in lowland fast flowing, white-water rivers, clearwater or blackwater rivers. The species is also present in the largest tributaries, lakes, confluences and seasonally flooded forests. It depends on healthy fish populations for its survival. Historically, the boto has been spared human persecution because of the belief that it has special powers. Today however, it is increasingly viewed by fishermen as an unwanted competitor for fish. The boto can get tangled up in fishing nets, or suffer wounds by colliding with boats. To date, no major reduction of their range has been observed.

"Counting dolphins is complicated, since they spend most of their time underwater," added Trujillo.

"If the researchers move slowly, the dolphins can overtake the boat and be recounted. We have designed a technique in which we generally hire big boats that have the possibility of placing the observers at least 5m above the deck so that they can have a good view of the river and thus count the animals."

Each time a scientist sees a dolphin or a school of dolphins, their position will be noted using GPS. Scientists will also register whether they are adults, young or new-born mammals, as well as record information about their habitat.

In addition to spotting the pink river dolphin, scientists will also be on the look out for  the grey river dolphin (Sotalia fluviatilis) — a dolphin species darker and smaller than the boto, with a shorter snout and a distinctive triangular dorsal fin.


• The Omacha Foundation is a non-profit NGO working to study, research and preserve flora and fauna with an emphasis on freshwater ecosystems in Colombia. The work is based on the mutual collaboration between researchers and the community with the aim of achieving plans for sustainable development of the freshwater resources.

• The Participants: Fernando Trujillo has more than 20 years of experience in river dolphin and aquatic fauna research. From 2007, he will take up the position of president of the Latin American Society of Aquatic Mammals (Solamac). Catalina Gómez is a researcher with the Omacha Foundation and has participated in several dolphine counts in the Amazon. Marcela Portocarrero is a researcher with the Omacha Foundation and also has experience in the conservation of fauna. Felix Daza is an investigator with the Wildlife Conservation Society (WCS) in Venezuela and is currently coordinating research in aquatic ecosystems. Carlos Lasso is a specialist in the ecology and taxonomy of fish in South America.

• Research Calendar:
May 9 to15: Observation in Colombia and Venezuela on the Orinoco River.
May 14 to 23: Observation in Peru (Pacaya-Samiria).
June 20 to 29: Observation on the meta River, Colombia.
Second half of July (10 days): Observation in Bolivia (Itenes-Mamoré).
Second half of August (10 days): Observation in Ecuador.

For more information:
José Saulo Usma, Orinoco Basin Programme Coordinator 
Tel. +57 2 5582577 Ext. 123

Luz Eliana Bossa Quintero, Media Consultant
Tel. +57 2 5582577 Ext, 217

Pink river dolphin, Orinoco River, Colombia.
© Fernando Trujillo / Fundación Omacha