ANCHORAGE — A population of Pacific harbor seals living in an Alaska lake could be another hurdle for developers proposing a massive open-pit copper and gold mine.
The Center for Biological Diversity on Monday petitioned the federal government for endangered species protection for harbor seals that live in Iliamna Lake about 200 miles southwest of Anchorage. The Pebble Mine poses a threat to the only known U.S. freshwater population of harbor seal, said spokeswoman Kiersten Lippman.
“They often don’t do well with human disturbance, in many cases, especially if they’re not used to it,” said Lippman, a biologist for the group in Anchorage.
The copper and gold mine would require a 140-mile road to a Cook Inlet port and would pass along 50 to 60 miles of lake shore, where seals hunt for salmon, Lippman said. Ocean acidification and warmer spawning streams brought on by climate change also are threats, she said.
“Anything that affects salmon would directly impact the seals,” Lippman said.
Iliamna Lake at about 75 miles long and 22 miles wide is Alaska’s largest. Seals are found on its east side more than 100 miles from saltwater.
The Pebble Mine is proposed near the headwaters of the largest sockeye salmon fishery in the world. The Pebble Limited Partnership, the group behind the project, has called the deposit one of the largest of its kind in the world, with the potential of producing 80.6 billion pounds of copper, 107.4 million ounces of gold and 5.6 billion pounds of molybdenum.
The proposed mine has been the subject of an intense public relations battle between developers and opponents who say it will affect salmon targeted by commercial fishermen, subsistence users and sport anglers.
Pebble Partnership spokesman Mike Heatwole said the company is aware of the inland seals through its baseline environmental work.
“Once we have a mine plan and a road corridor, we’d have to take appropriate environmental safeguards for these and any other animals,” he said.
No natural barriers prevent the seals from saltwater access, he said, and debate continues as to whether they differ from ocean seals.
“Whether or not they’re a distinct population has not been established or demonstrated in the literature and studies that have been conducted,” he said.
Lippman said the seals’ year-round status in the lake was documented with winter sighting in 2009 and pupping in 2010. They are thought to be able to stay year round by using cracks in the ice, ice caves or underground caves, according to the petition.
They give birth to pups a month later than the closest population in Bristol Bay. They have darker pelts, fur with a distinct pattern, and larger heads and bodies. Their primary prey in summer and fall is salmon, according to the petition. They may also feed on freshwater fish.
Mining trucks would create noise disturbance for seals, she said. A road would create silt in streams and culverts could stop seals’ access.
The petition contends that virtually all of the world’s largest copper-sulfide mines have had failures that degrade water quality.
Julie Speegle, spokeswoman for the National Marine Fisheries Service, said by e-mail that the agency will review the petition and make a 90-day finding as to whether a listing may be warranted.