Bright lights that affect the behavior of birds, fish and other wildlife are emerging as a significant environmental concern.
Photo: B. Zaun, U.S. Fish and Wildlife Service
Yesterday, for example, two environmental groups filed a lawsuit against the Hawai’i Department of Transportation for bright lights the agency controls at piers and airports. The groups say three species of seabirds on the Endangered Species List have been circling the lights until the birds drop from exhaustion, and some birds have died.
Meanwhile, in Lake Washington and the nearby Cedar River in King County, there is evidence that threatened chinook salmon are at greater risk from predators because of lights on the two floating bridges as well as industrial facilities in Renton.
In Florida, researchers have discovered that female turtles avoid coming ashore to lay their eggs where bright lights are present, and in Virginia salamanders have delayed their feeding efforts in the glare of lights.
The lawsuit in Hawaii was filed by lawyers for Earthjustice out of concern for three species of seabirds: Newell’s shearwater, a threatened species, and Hawaiian petrels and band-rumped storm petrels, both endangered species.
The Hawai’I Department of Transportation has failed to protect the birds, as required by the Endangered Species Act, according to the lawsuit filed on behalf of the Hui Ho‘omalu i Ka ‘Āina, Conservation Council and the Center for Biodiversity. Because the lighting is injuring and killing listed species, the state agency must obtain an incidental take permit and initiate actions to minimize harm, the lawsuit says. For details, see the complaint for declaratory and injunctive relief (PDF 1.4 mb).
Lights at airports and harbor facilities have been documented as the greatest source of injury and death to the seabirds, which migrate at night and become disoriented by the artificial lights, the complaint asserts. Some birds crash into buildings, while others end up on the ground where they may be struck by vehicles or eaten by predators.
Since the 1990s, the Newell’s shearwaters have declined by 94 percent and the Hawaiian petrels on the island of Kauai have dropped by 78 percent.
“Our ancestors depended on the ‘a‘o (Newell’s shearwater), ‘ua‘u (Hawaiian petrel) and ‘akē‘akē (band-rumped storm-petrel) to help locate schools of fish, to navigate from island to island and to know when the weather is changing,” Kauai fisherman Jeff Chandler was quoted as saying in a news release from Earthjustice.
According to the news release, the Department of Transportation dropped out of talks with state and federal wildlife agencies that are developing a habitat conservation plan to protect the seabirds. After Earthjustice filed a notice of intent to sue, the agency rejoined the talks.
“That’s a good start, but talk alone will do nothing to save these rare and important animals from extinction,” said Earthjustice attorney David Henkin. “It’s long past time for the department to take action, not only on Kauai, but everywhere in the state that its operations illegally kill seabirds.”
Lake Washington chinook
As for the lights on and around Lake Washington, I have not heard of any proposed lawsuits to protect the threatened Puget Sound chinook, but concerns continue to simmer.
Photo: Washington Dept. of Transportation
Jason Mulvihill-Kuntz, salmon recovery manager for the Lake Washington/Cedar/Sammamish Watershed, told me that the next regional chapter of the chinook recovery plan will call for further study into the effects of lights on juvenile chinook migrating down the Cedar River and through Lake Washington.
“The technical folks have identified light as a potential emerging issue,” Jason said. “We don’t have a good handle on what the impacts are.”
Lights on Lake Washington may be creating a double whammy for young chinook, Jason said. First, the lights attract the fish, which slow down their migration to Puget Sound. Second, the lights keep them visible to predators at night, so the fish may be eaten 24 hours a day.
“Juvenile salmon don’t have a nighttime respite,” Jason said. “At least that’s the hypothesis.”
Nonnative predatory fish include bass, walleye and northern pike. Native predators include cutthroat trout and pike minnow. Predatory birds include the western grebe and great blue heron.
An updated chinook recovery plan for the Lake Washington region is under review and could be finalized this fall. Predation is getting some additional attention this time around, Jason said, and the issue of lights is something that needs more study.
Experts at the U.S. Fish and Wildlife Service have identified potential concerns with lighting along Lake Washington in a series of studies going back more than 10 years. It still isn’t clear, however, how much the known problems with predators are exacerbated by bright lights. That’s why more studies are needed.
Following complaints from residents of Laurelhurst near the Highway 520 bridge, the Washington Department of Transportation reduced the amount of illumination coming off that bridge, and further investigation is underway. Check out the King-5 News report below.
Other species
With regard to other species, lights are known to have a variety of effects. Reporter Sharon Guynup outlined the problems for birds, turtles, amphibians, mammals and even insects in a revealing story in National Geographic News, April 17, 2003.
A group of British researchers from the University of Exeter compiled a list of the known effects of light on various species while considering the role of artificial lighting. See “The ecological impacts of nighttime light pollution; a mechanistic appraisal” in Biological Reviews.
