It is one of the longest power lines in the world and promises to deliver a much needed reliable energy supply to isolated populations in the north of Brazil. But the Tucuru铆-Macap谩-Manaus power line has come under fire by environmentalists, who say its construction will gouge a 70 metre wide trail through one of the Amazon鈥檚 most precious nature reserves 鈥� with severe consequences for wildlife and research.
The line, known informally as 鈥淟inh茫o鈥� 鈥� Portuguese for 鈥渂ig line鈥� 鈥� has been in construction for over five years, and last year reached the city of Manaus, which is situated in the middle of the Amazon. The line runs from the Tucuru铆 Dam, which is about 1200 kilometres away on the Tocantins River. It supplements the woeful contribution of Manaus鈥� local dam, Balbina, which failed to meet engineering expectations and produces less than 20 per cent of the electricity the bustling mid-Amazon city requires.
Having reached Manaus, Linh茫o is now heading 750 kilometres north to bring electricity to Roraima State鈥檚 capital, Boa Vista and other towns on the way .
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Mind the gap
But this stretch of the line is creating a problem. Just outside Manaus, it is planned to cross the Adolfo Ducke Forest Reserve, run by the National Institute for Amazonian Research (INPA). Ducke is one of the premier rainforest research sites in the world, and much of what is known about Amazonian ecology comes from this reserve.
No INPA scientist would deny the local need for electricity, but there are grave concerns about the local impacts.
鈥淭he problem is not the line itself,鈥� says at James Cook University, in Queensland Australia, who studies tropical rainforest disturbance and is a long-time Amazon researcher. 鈥淚t鈥檚 the zone cleared underneath.鈥�
The line is suspended above the canopy on pylons and to allow for maintenance of the towers, a path up to 70 metres wide is being built under the power line, all along its length. 鈥淭his may not sound much鈥�, says Laurance, 鈥渂ut for many rainforest animals, that鈥檚 an unbridgeable space鈥�.
Nocturnal animals such as jaguars are likely to be intimidated by a block of open habitat that is full of light. Important food species 鈥� such as the guinea-pig like rodents, agouti and paca 鈥� are also unlikely to risk crossing land with no plant cover.
Some large canopy-dwelling birds, such as macaws and toucans, will not be put off, but a lot of smaller species have been shown in tagging experiments in isolated forests to be reluctant to cross such gaps.
Islands in the forest
鈥淚f the line severs the connection between the reserve and neighbouring forest, Ducke will become an island,鈥� says of Louisiana State University, who has studied the region鈥檚 birds for more than 20 years. 鈥淥ur studies show such isolation leads to rapid species loss.鈥�
INPA scientists are now preparing a petition to state their feeling that the reserve is simply too important to lose.
In discussions with Eletrobras, the Brazilian government鈥檚 electrical utilities company, the INPA tried to negotiate measures to minimise the project鈥檚 impact, such as shifting Linh茫o a couple of kilometres to bypass the reserve and creating smaller, site-specific access trails to each pylon. Elsewhere on Linh茫o, Eletrobras made amendments to its plans to accommodate larger landowners. The company has not responded to a request for interview, but the INPA says that, with regards to the forest reserve, all these suggestions were refused.
