top of page
About the Poison Drop

On July 23, 2017 the Hawaii Department of Land and Natural Resources and US Fish and Wildlife Service issued a Finding of No Significant Impact for an aerial drop below the high tide mark of approximately 11.5 tons of diphacinone rodenticide onto the 284-acre State Wildlife Sanctuary of Lehua and its surrounding waters. 


A series of aerial drops occurred on Lehua in August and September 2017. If the diphacinone applications do not achieve the agencies' intended goal of100% eradication, a follow-up application of the more lethal rodenticide, brodifacoum, will be aerially dropped in the same manner, in August of 2018.




Lehua Island is roughly 18 miles off the coast of Kauai and 3/4 mile from the island of Ni'ihau, one of the only native Hawaiian speaking communities in the state, the Ni'ihauans.

Lehua and its waters provide a breeding and feeding habitat for seabirds, whales, endangered monk seals, green sea turtles and three bird species protected under the Endangered Species Act. Food web systems and relationships are complex and largely under-researched in this wildlife sanctuary area. Mortalities of non-target species, through primary and secondary poisonings (ie, ingesting poisoned prey), are deemed possible in this aerial drop, according to the Final EA's issued by DLNR and USFWS.

Despite significant concerns expressed at every public meeting and readers' comments in local news articles, DLNR continues to move forward. Though all permits and consents have not been obtained as of August 9, 2017, DLNR and USFWS staff with its sole source contractor (a private consultant group based on the mainland) have been staging on Lehua and Kauai in preparation for the operation.


Hawaii Department of Agriculture (HDOA) Grants Investigation into Effects of Diphacinone in Ecosystems:

In response to a request by a former head of the Pesticides Branch of the Department of Agriculture, on July 31, 2017 the Hawaii Department of Agriculture (HDOA) confirmed its launch of an investigation of the rodenticide DITRAC D-50 and its active ingredient, diphacinone. 

DITRAC D-50 is the rodenticide selected by DLNR and USFWS for the Lehua poison drop.

The legally mandated investigation will focus on whether the rodenticide is likely to cause unreasonable adverse effects to the environment and to humans. The investigation will take into account the unexplained deaths of fish and mammals, including three whales, that occurred following aerial drops of diphacinone rodentidice at Lehua Island (2009), Mokapu Island (2008) and Keauhou Ranch (2003). A conference presentation by the head of HDOA Pesticides Branch in 2009 provides findings that cause concern about the effects of diphacinone to ecosystems, including marine ecosystems.

The letter from HDOA confirming the investigation states that as a result of the investigation process HDOA "may suspend the license of a pesticide immediately if necessary to prevent an imminent hazard."


In a letter dated August 2, 2017 state Representative for west Kauai, Daynette (Dee) Morikawa urged DLNR head Suzanne Case and Department of Agriculture head Scott Enright, with a cc: to Govenor David Ige, to consult with the westside community and reconsider their actions in light of the failed aerial drop of 2009.

On August 8, 2017, DLNR head Suzanne Case replied to Representative Morikawa with a letter stating that "the project will continue." And despite the ongoing formal investigation to diphacinone by HI Department of Agriculture, its head administrator Scott Enright, issued the permits to allow the aerial broadcast of rodenticide into Lehua's nearshore waters.

There is now mounting public inquiry into how and why Case's agency, DLNR, purchased the DITRAC D-50 rodenticide directly from its manufacturer, Bell Laboratories, circumventing state regulatory reporting rules. The purchase may have been made in derogation of state law regarding sales of restricted use pesticides to be used Hawaii, and prior to any official permit approval by the Department of Agriculture.


Transport of the DITRAC-50 pesticide to its staging ground on nearby Ni'ihau, also without DLNR having first obtained permit approval by the Department of Agriculture, is also being questioned.

State House Representative Dee Morikawa reiterated her request to hold off on the aerial drop on August 8, 2017.  The aerial drops nevertheless proceeded.



In early September 2017, days after the second of three aerial drops, a mass die-off of reef fish and many seabirds was video-recorded on Lehua's shores.


One week after this incident was made public, DLNR and USFWS, with the official permit granted by the Hawaii Department of Agriculture, nevertheless executed its third poison drop without any prior notice to the public.


On October 13, 2017, approximately one month following the diphacinone aerial drop, five pilot whales stranded and died on the nearby shores of Kaua'i in a mass stranding witnessed by hundreds of onlookers. Many more stranded pilot whales were led back to deeper waters by the tremendous efforts of local Kaua'i residents, preventing an even more devastating whale death toll. 


Scientists and researchers immediately and formally requested forensic testing under specific lab testing protocols for liver, stomach contents, blood and tissue. Such requests called for the lab testing of any detectable level of diphacinone, including "sub-lethal dose" levels. This data is greatly needed since there is currently no data available on the effect of this anticoagulant rodenticide on cetaceans (whales, dolphins and their close relatives). 

To date, DLNR and USFWS have not yet released any lab test results from the dead bird or fish specimens collected by them in early September, though agency representatives had stated that such results were expected by early October.


Source citations:

(Links to specific source documents also included above):

Final Environmental Assessment July 2017 issued by US Fish and Wildlife Service and Hawaii Department of Land and Natural Resources, Division of Forestry and Wildlife and accompanying citations.

Endangered Species Act:16 U.S.C. § 1531 et seq.

Hawaii Administrative Rules (2006) Section 4-66-32.1.

Hawaii Revised Statutes Section 149A-14(c).

Photo: Final Environmental Assessment (July 2017) USFWS

Recent articles on public reaction to the aerial drop:
OP-ED: Despite Research, Preparations, Rat Concerns Remain
(The Garden Island Op-Ed, August 24, 2017)
OP-ED: Delay of Rat Poison Would Be Best
(The Garden Island  Op-Ed, August 7, 2017)
Objections Rise to Poison Plan
(The Garden Island, August 4, 2017)
State to Investigate Poison Use Planned for Lehua
(The Garden Island, August 3, 2017)
Questions Still Rising Over Rat Poison Plan
(The Garden Island, July 28, 2017)
The Lehua Aerial Poison Drop – Endangering Native Hawaiians and the Local Fishing Industry?
(Huffington Post, June 7, 2017)
Reaction of Ni'ihauan community to the failed 2009 aerial rodenticide drop:
Ni'ihau Residents Upset by New Eradication Plan
(Honolulu Advertiser, October 2009)
More press to follow.
bottom of page