State drops rodenticide amid concern

The state proceeded Wednesday with the first of three rodenticide bait drops in the latest effort to eradicate rats on a tiny island off Niihau.

Amid community concern over whether rodenticide poses a threat to marine life and the environment, the Department of Agriculture approved a permit Tuesday that allowed the Department of Land and Natural Resources to use the diphacinone rodenticide on Lehua Island in hopes of creating a predator-free sanctuary for endangered and threatened seabirds.

Permits have yet to be approved for the two additional applications planned by the department in the next few weeks.

On Wednesday, cylinder-shaped pellets containing diphacinone were dropped from a hanging bucket by a helicopter and spread onto steep terrain on the 284-acre island.

Island Conservation, an organization involved in the project that advocates for the removal of invasive species, said Wednesday’s operation was conducted safely. “Everyone was pleased with how the operation went,” spokesman Heath Packard said.

According to Packard, 99.995 percent of the bait was composed of nontoxic, human food-grade material and the remaining fraction — five parts per million — was diphacinone.

The total amount of pellets that will be spread on the island in three applications is approximately 11 tons. Should any pellets enter the water, Packard said, the diphacinone itself will eventually decompose and break down into nontoxic compounds.

In the past 10 days, Island Conservation has stepped up outreach efforts to address concerns about using rodenticide.

The Agriculture Department also said it has worked closely with area lawmakers to address community concerns and ensure appropriate safety measures and procedures are in place “to minimize any adverse effects to marine mammals, fish and wildlife.”

Agriculture Department Chairman Scott Enright was on Niihau to monitor the application. “He’s been giving the project the utmost scrutiny,” Packard said.

Pesticide enforcement staff were also present during the aerial drops and will continue to monitor the island after all applications are completed.

State Rep. Dee Morikawa, who represents Niihau and Lehua islands and Koloa and Waimea on Kauai, said there are a lot of people angry about the eradication project.

Earlier this month, Morikawa sent a letter to DLNR requesting that the state delay the bait drops until concerns about the possible effects of rodenticide on marine mammals, fish and coral reef were addressed. The land agency had originally planned to start the bait application on Aug. 8 but was still awaiting permits.

Morikawa sent the letter after she attended a July 25 public informational meeting, the third informational meeting on the eradication project, where the state and consultants were to discuss the final environmental assessment on the project. But the meeting was contentious and “angry exchanges” occurred between residents and consultants.

Suzanne Case, chairwoman of the Department of Land and Natural Resources, responded to Morikawa’s letter saying the rodenticide would have no significant impacts to marine life or the environment.

Case also said diphacinone in a previous eradication project wasn’t detected in samples of fish tissues. She added there were no records of Hawaiian green sea turtles nesting on Lehua Island and data showed the rodenticide did not impact coral.

“Given the relatively low toxicity of the product being used and the successful use of this technique around the world, we feel confident that the project will succeed in removing rats with no significant impact to the surrounding environment,” she wrote in the letter.

This is the state’s second attempt to rid the island of rats. The first took place in winter 2009, when the rodents weren’t completely eradicated because there was enough vegetation for them to consume instead of the bait pellets.

Of the latest effort, Morikawa said, “I’m hoping for the best.”

For information on the Lehua Island restoration project, visit lehua-island.com.