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Regional Overview: Hydroelectrics and illegal mining threaten South American river dolphins

This is one of the main results of the first satellite monitoring of river dolphins completed in Bolivia, Brazil, Colombia and Peru as part of the South American River Dolphins Initiative. The analyzes reveal a purpose of the World River Dolphin Day.

  • This is one of the main results of the first satellite monitoring of river dolphins completed in Bolivia, Brazil, Colombia and Peru as part of the South American River Dolphins Initiative.
  • The analyzes reveal a purpose of the World River Dolphin Day.

October 24th, 2019 - In the past, river dolphins roamed the Orinoco and Amazon basins without limitations. However, more than 140 hydroelectric plants operations and the planning of 160 in the Amazon biome have changed this landscape and are accomplishing worrying consequences for this cetaceans conservation. Why? Dams isolate dolphin populations, leaving them disconnected from the main channels, also the interrupted fish migration is generating a significant threat to their reproduction, in addition to the high mortality of eggs and juveniles in hydroelectric turbines. Fishes are the main food on dolphin populations.
These are just some alerts identified by a group of scientists after monitoring for the first time, with satellite tags to 29 river dolphins of the Inia geoffrensis species, known as pink dolphins, and Inia boliviensis or Bolivian bufeo. This monitoring was done between 2017 and 2019, in six large river basins throughout Bolivia, Brazil, Colombia and Peru, where these cetaceans move, feed and reproduce.
The results of this work are part of the South American River Dolphins Initiative (SARDI), formed by the organizations Faunagua, Fundación Omacha, Mamirauá, Prodelphinus
 and WWF. The group promotes the freshwater dolphin’s conservation and their habitats with strategies such as satellite monitoring. Its goal has been to get access to scientific information about both these species and their habitats, their movements, food, the impact of threats such as mining and the negative effects of climate change to have greater inputs for their conservation.

“When we better understand the ecology of animals and their movements, as is happening now, we can propose more effective conservation actions. It is very important to continue this regional effort just at a time when we have seen the magnitude of the fires in the Amazon. These have an impact on aquatic ecosystems, so monitoring species is even more important to also know about the health of forests and rivers in the Amazon and Orinoquia basins,” explains Marcelo Oliveira, WWF-Brazil conservation expert and SARDI Coordinator.

The impact of mining
Another of the outcomes of the satellite monitoring advanced by SARDI has to do with the threats of illegal mining and mercury to the rivers of South America and its ambassador species: dolphins. According to the analyzes made to the tissues of these cetaceans, 100% of the muscle samples analyzed have high mercury contents. This heavy metal, wich is used in gold extraction and the native forest incineration, pollutes water and air, accumulates in plants and animals and, through food, threatens species such as river dolphins, and health and livelihoods of millions of people.

In addition to the warnings, SARDI experts also confirmed key data for the dolphins conservation as their movements do not have border boundaries among countries. These animals use transboundary wetlands for food, shelter and reproduction, so they need healthy rivers connected regionally. "For this reason, we need to support protected areas and even increase more aquatic ecosystems protection in the region," said Fernando Trujillo, scientific director of Fundación Omacha.

Additionally, monitoring also showed that dolphins use different aquatic environments to live: areas of confluence of rivers, lagoons, river and tributary channels, and even shallow areas near the beaches, where they mate. In addition, these areas are changing throughout the year in response to the water level and the flood pulse. For this reason, the control of the flows by hydroelectric, can affect the cycle of life in the Amazon, in wetlands and flooded forests important for dolphins and fish. The reduction in fish stocks due to the transformation of their habitats could increase conflicts between fisheries
and dolphins and endanger the food sovereignty of millions of people who use these resources.
The main challenges
One of the most important milestones for the group of NGOs that make up SARDI is that these results are taken into account for the development of a Management Conservation Plan (CMP) for river dolphins, which would be supported by the International Whaling Commission, as a result of a coordinated effort between governments. This is the highest international scientific organism responsible for regulations related to cetaceans. Thus, the CMP aims to mitigate threats to freshwater dolphins in South America.
In the following phases of satellite monitoring, SARDI researchers want to obtain information about the pressure of river dolphins that are used as bait to catch a species of fish known as mota (in Peru, Colombia), piracatinga (in Brazil) or blanquillo (in Bolivia). Finally, they also seek to have more data on areas where roads or hydroelectric plants should not be built in order to be able to plead with the governments for the protection of river dolphins and their ecosystems in the Amazon and the Orinoquia.
About mining and hydroelectric threats, the implementation of international agreements for protection of human health, ecosystems and species, such as the Minamata Convention, is urgent. This raises the definitive elimination of the use of mercury and has been ratified by all amazon countries, except Venezuela. This is a very significant step for the Amazon region, where the health of millions of people has been affected due to the impact of this heavy metal. Now governments must implement actions to make this agreement a reality.
On the other hand, in terms of hydroelectric plants, although they are an energy solution today, they also mean a food problem for tomorrow. “Why insist on these enormous infrastructures if we can obtain energy from renewable sources? SARDI has analyzed the impact of hydroelectric plants, such as those built in the Madeira River (Brazil), where in the next five years the populations of fish that migrate long distances, such as Catfish, and where the “Bolivian bufeo” could be affected by lack of food, said Paul Van Damme, director of Faunagua (Bolivia).

For further information, please contact to:
Verónica Téllez | Communications officer WWF-Colombia | vetellez@wwf.org.co  
South American River Dolphins Initiative website: www.river-dolphins.com
River dolphins
Pink dolphin
Pink dolphin
The Bolivian River Dolphin

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