Tests can’t say if rat bait killed Lehua Island fish

Preliminary results of samples taken from dozens of dead fish found on Lehua Island during the state’s rodent eradication project are “inconclusive” as to whether rodenticide killed the fish, the Department of Land and Natural Resources said this week.

Three rounds of rat bait containing the anticoagulant diphacinone were scattered on the 284-acre island via helicopter in August and September in an effort to protect threatened and endangered birds. The project was initiated amid community concerns over whether the bait would pose a threat to the marine environment. Video of the dead fish and two birds was posted on social media after the second application.

About 45 dead mullet and two dead juvenile booby seabirds were collected from a tide pool on the northern side of the island. Tissue samples were sent to the state Department of Agriculture and the U.S. Department of Agriculture Animal and Plant Health Inspection Service’s National Wildlife Research Center for analysis.

DLNR reported that preliminary findings by the agriculture department and research center indicated tissue samples were “in a severely degraded condition,” making it impossible to determine whether the fish were affected by diphacinone or died due to other factors.

The state is expected to release a final report sometime in December.