Environmentalists say they will urge a renewable-energy
developer to relocate a planned solar project in the Mojave Desert
to avoid harming a population of genetically unique desert
tortoises.
Environmentalists say they will urge a renewable-energy developer to relocate a planned solar project in the Mojave Desert to avoid harming a population of genetically unique desert tortoises.
BrightSource Energy proposes to use 6.2 square miles of public land near Interstate 15 at the eastern border of San Bernardino County to install thousands of mirrors that will focus heat on water-filled steel boilers mounted on towers. The steam would drive turbines to generate clean electricity for some 140,000 homes.
The project is being watched closely because it would be the first large-scale solar development in a wave of proposals triggered by California’s mandate that utilities supply 20 percent of their customers’ power needs with renewable energy by this year and 33 percent by 2020 to reduce greenhouse gas emissions. More than 120 solar and wind projects have been proposed on public land in the California desert.
The federal government also is pushing for large-scale alternative energy development and announced in November that BrightSource’s project would be fast-tracked.
Some environmentalists say the solar array, as proposed, would destroy prime habitat for the desert tortoise, a species listed as threatened with extinction, in the Ivanpah Valley between I-15 and the Clark Mountains.
The animals have unique genetic characteristics that could be important to the species’ survival, and moving them could put them at risk, said Ileene Anderson, a biologist with the Center for Biological Diversity.
Last year, Army officials stopped relocating tortoises from Fort Irwin after dozens of the reptiles died, mostly as a result of coyote attacks.
Anderson’s group, the Sierra Club and the Western Watersheds Project are expected Monday to attend a California Energy Commission hearing in Sacramento focusing on environmental issues BrightSource faces.
Representatives of the groups say the solar development could be built on land closer to I-15 or on a dry lake bed that is poor tortoise habitat but has just as much sunshine.
Keely Wachs, a spokesman for the Oakland-based BrightSource, decline to comment on calls to move the project. He said such concerns will be addressed during this week’s public hearing.
Documents submitted to the energy commission say the company plans to move about 25 tortoises to other parts of the Ivanpah Valley.
Wachs said the company will protect tortoise habitat elsewhere that is three times the size of the land taken for the solar development.
Environmental groups say it’s important to protect the Ivanpah Valley tortoises because of their uniqueness.
A 2007 study published in the journal Chelonian Conservation and Biology found that the Ivanpah tortoises are genetically different from most other desert tortoises.
That most likely is because mountain ranges isolated the population from other tortoise communities, said the lead author, Robert W. Murphy, senior curator of herpetology at the Royal Ontario Museum in Toronto.
“There is genetic variation in that population that is unique, and that diversity is something we want to maintain,” Murphy said Friday in a telephone interview.
The researchers analyzed DNA and completed other genetic tests on blood from 753 Mojave tortoises. The blood was gathered for federally funded disease studies.
The study did not identify what the genetic differences are, but Anderson noted that the Ivanpah tortoises’ shells appear to be less round than those of tortoises in other parts of the Mojave Desert.
Genetic diversity is important to the survival of all animals but especially to those, like the desert tortoise, on the brink of extinction, said Michael Connor, a wildlife biologist and California director of the Western Watersheds Project. He said he will speak at Monday’s hearing.
The greater the genetic diversity, the more traits a species will have in its evolutionary toolbox to recover or survive changing conditions, Connor said.
Since the Ivanpah tortoises have adapted to a higher-altitude valley at 3,200 feet, they may have traits needed for the species to survive global warming, which is expected to force many plants and animals to move to higher, cooler ground, he said.
BrightSource’s Wachs declined to answer questions about the genetic study, saying it would be addressed at the energy commission hearing.
Sid Silliman, a member of Sierra Club’s San Gorgonio Chapter, said in a letter to the energy commission that large-scale solar projects like BrightSource’s proposal are needed to reduce global warming. But such projects should go on land already disturbed by farming and other human activity, and preferably on privately owned land, he said.
