An investigation is underway after dead birds and fish were discovered on Lehua Island.
The state Department of Land and Natural Resources is in the middle of a project to eradicate invasive rats by dropping bait pellets containing diphacinone, which is a type of rodenticide.
The first two rounds of bait were dropped on Aug. 23 and 30.
A third drop, scheduled for Sept. 9, is on hold after pictures and video of dead fish and green powder made the rounds through social media.
The images prompted project partners to deploy teams, which collected 45 dead fish, which appear to be mullets, and two dead birds, which appear to be juvenile brown boobies, from the island’s north, or crater end.
The group Island Conservation, which partnered with the state to conduct the rodenticide drops, says it’s now taking a step back to figure out if the poison is responsible for the death of those animals.
The group says it has done hundreds of similar projects in places like New Zealand, Australia, Chile, and Ecuador. All have been successful, the group says.
“The science that we evaluated, and has been used and has driven more than 500 successful projects like this around the world, does not indicate a high likelihood of the causal relationship between the incidents of fish mortality and bird mortality,” said Heath Packard, Island Conservation’s director of communications. “It’s possible, but we need data to demonstrate to the public and agencies and the rest of us if there is a causal relationship.”
The island off Niihau is one of the largest and most diverse seabird colonies in the main Hawaiian Islands with 17 seabird species and 25 native plants.
DLNR says invasive rats threaten that ecosystem by eating the seabirds and destroying native plants.
Kauai Rep. Dee Morikawa says she was against the project from the beginning.
“I tried. I raised the alarm. All I could do was have them answer questions, assure people it would be okay,” Morikawa said. “I talked to an ex-employee responsible for last drop in 2009 who had concerns today. Sure enough, it’s happening.”
The samples are under USDA chain-of-custody and will be processed to determine likely cause of death or presence of diphacinone.
“They took the fish and are going to have it tested. You know it has to be from the rodenticide, although they’re saying we’re going to see. Okay, so now what? Now that all this fish have been contaminated, what does that do to the food chain?” Morikawa said.
Officials say while there are inherent short-term risks, fish are least likely to be affected by the rodenticide since they reject the bait, which then sinks to the sea floor and degrades into non-toxic compounds.