A pair of proposed hydroelectric dams that will encroach on the habitats of critically endangered primates—in Guinea and Indonesia—are receiving fierce criticism from conservation groups, who fault what they call inadequate scientific review of the harmful effects of these big infrastructure projects.
The government of Guinea was finalizing plans last week for the construction of a 294-megawatt hydroelectric dam in the country’s Moyen Bafing National Park, which wildlife experts say could lead to the loss of up to 1500 critically endangered western chimpanzees (Pan troglodytes verus), a subspecies whose population has fallen by more than 80% over the past 20 years. Guinea created the national park only this year as a refuge for an estimated 4000 chimpanzees.
A dam planned for Sumatra in Indonesia faces similar criticism; constructing the roads, tunnels, and power lines necessary to service the dam would deforest the habitat of the Tapanuli orangutan subspecies (Pongo tapanuliensis), discovered only last year, which has a remaining population of just 800 apes.
Environmental and social impact assessments (ESIAs)—reports detailing a project’s expected effects on their local ecosystems and human populations—were completed for both dams, but scientists say they underestimate how many primates will be affected. The ESIA for the Guinea dam—commissioned by the World Bank, which is coordinating the project, and the Guinean government—estimates that about 200 to 300 primates will be lost. But the number is closer to 1500, says Rebecca Kormos, a primatologist at the University of California, Berkeley, and a member of the International Union for Conservation of Nature’s Primate Specialist Group.
The ESIA did not use the most scientifically rigorous method for surveying how many chimpanzees live near the dam, Kormos says. To count populations, most primatologists conduct transect surveys, which involve traversing a habitat for several days in predetermined lines, usually off-trail, counting the number of ape nests, and extrapolating based on a geographic model. The ESIA’s contractor used a method known as reconnaissance or recce surveys, which also involve counting nests but may avoid difficult terrain; recce surveys are usually less expensive and time-consuming than transects. Kormos says the ESIA also did not factor in the subspecies’s natural territoriality and the deaths that will result from infighting when displaced chimpanzees end up on each other’s turf.
“The ESIA really isn’t based on the best practices of how to study these primates,” Kormos says. “It ends up really underestimating how devastating this dam will be for these chimpanzees.”
The second dam, planned for Sumatra, is opposed by the Alliance of Leading Environmental Researchers & Thinkers (ALERT), an international group of scientists headed up by Bill Laurance, a professor of biology at James Cook University in Townsville, Australia. Laurance says the 510-megawatt project, funded in part by the Bank of China and the Chinese power company Sinohydro, will be “a death blow” to the Tapanuli orangutans but the ESIA mentions only the direct effects of flooding from the dam on a small number of orangutans. “It does not look at secondary, tertiary effects, like roads, power lines, the influx of illegal logging, poaching, and colonization that so often come along with big infrastructure,” he says. Studies conducted by Laurance and other ALERT members have shown that fragmentation of the orangutans’ forested habitat by roads is the greatest threat to their survival. The ESIA was “myopic,” he says, adding, “If you imagine nature dying the death of a thousand cuts, the ESIAs are studying each cut individually.”
The Sumatra dam is emblematic of “a whole set of problems” related to ESIAs and land use regulation in developing nations, Laurance says. One problem, he says, is that the project proponents typically pay for the reviews. “It’s widely known among the consultancy groups that carry out the ESIAs [that] if they come down too hard on the corporations, in particular if they recommend project cancellation, that they’ll be quickly black-balled,” he says.
Despite local protests and letters written by ALERT to the Indonesian government, forests are already being cleared in preparation for the dam. Last week in Guinea, a 2-day conference was held for government officials and the project’s managing board to discuss the ESIA for that project. A source at the meeting says that the project’s coordinator has asked for more information to be added to the ESIA by the end of September, but it is unclear as to who will carry out the additional studies and whether construction on the dam will begin before the report is expanded.
A spokesperson for the World Bank Group said in a statement that the proposed impact assessment developed by it and partners recommends “mitigation measures that ensure protection of people, wildlife, and biodiversity. Once we are satisfied that our recommendations have been adequately considered, we will proceed with the validation of the final ESIA.”
*Correction, 17 July, 10:10 a.m.: An earlier version of this story misspelled Bill Laurance's name.