13 river, 5 nation river dolphin census to help conservation on two continents
The census, which took two years and recorded 3188 pink and gray dolphins in 3.600 km of rivers in the Amazon and Orinoco basins, was key to development of a standard methodology for assessing river dolphin populations and the threats they face.
“This census gives us a baseline population for these species and gives us an insight into the state of the ecosystems they inhabit,” said Fernando Trujillo PhD, the project's scientific leader.
Trujillo, Scientific Director of the Omacha Foundation and winner of the Whitley Award last year for his work with river dolphins, said “These results also provide the foundation for designing an evaluation and monitoring program for South American river dolphins.”
During the seven expeditions involved in the survey, training in the new methods was given to 18 professionals. The new methodology has also been certified by whale experts from the International Union for the Conservation of Nature (IUCN)
“Although the situation for river dolphins in South America is not the same as for dolphins in Cambodia, for instance, both have areas where we need to raise the alarm against threats like pollution, indiscriminate hunting and the development of infrastructure megaprojects,” Trujillo said.
The survey was also notable as a highly successful exercise in co-operation. The census was financed by WWF Switzerland and WWF LAC’s Freshwater Program. Scientific leadership from the Omacha Foundation included WWF (Colombia, Bolivia, Peru and Brazil), WCS (The Wildlife Conservation Society, Venezuela, Colombia, Ecuador, Peru, Bolivia and Brazil), WDCS (Whale and Dolphin Conservation Society), La Salle Foundation (Venezuela) and Faunagua (Bolivia). The statistical reliability of the research was certified by the University of St. Andrews (Scotland) Distance Program, through Fernanda Márquez (co-author of the Distance Program and Director of WCS Brazil).
The survey also involved the co-operation of wildlife and other officials from Venezuela, Ecuador, Peru, Bolivia, Brazil and Colombia.
“This first river dolphin census has been an experience in networking, which, besides giving scientific results, has opened doors to consolidate WWF’s work around the world for these charismatic species,” said Saulo Usma, WWF Colombia’s Freshwater Coordinator. “In April this year, we will meet in Santa Cruz de la Sierra in Bolivia, with experts from various organizations to consolidate a South American river dolphin conservation strategy, which will be published as a IUCN Occasional Paper, and adapted to each country’s national action plan.”
Two initial projects are likely to emerge from this meeting. One is a campaign to reduce dolphin poisoning in Caballo Cocha (Lake) in Peru, where fishermen have been injecting agricultural chemicals into fish in attempts to reduce dolphin damage to catches and nets.
Some 25-30 dolphins have been discovered dead by poisoning in the lake in the last year. Fundacion Omacha is working to monitor the situation. Possible ways of reducing fisher-dolphin conflict include increasing dolphin-related tourism income and of assisting fishers to fillet, pack and freeze fish, allowing them to receive better returns than from whole, fresh and sometimes dolphin-damaged fish.
Also contemplated is a plan to reduce unsustainable fishing for mota (catfish) using dolphin as bait on the Colombia-Brazil-Peru triple border. Mota fishing has increased markedly as fishers explore the possibility of marketing it as the more desirable but rare from overfishing Bagre catfish.
Unfortunately for Amazon River dolphins however, Mota are scavengers and dolphins represent the largest available easily caught bait fish. Fundacion Omacha and WWF are working in Brazil and Colombia not just on educating fishers but perhaps more effectively seeking to inform consumers and the retail chain on the switching of fish and its consequences for dolphin populations.