LIHU‘E — As authorities test samples, community members continue to speculate on the cause of a massive fish kill reported earlier this month on Ni‘ihau and the death days later of a young humpback whale on Kaua‘i. Some residents suspect
LIHU‘E — As authorities test samples, community members continue to speculate on the cause of a massive fish kill reported earlier this month on Ni‘ihau and the death days later of a young humpback whale on Kaua‘i.
Some residents suspect a recent federally administered rodenticide application on the uninhabited island of Lehua may be linked to the dead fish that have washed ashore there and on the nearby Forbidden Island.
But preliminary data has not revealed any direct correlation between these deaths and the rodenticide applications, which were administered Jan. 6 and Jan. 13.
“We’re fairly confident that diphacinone did not play a role in the fish kill, but it cannot be ruled out until all findings have been revealed,” said Kenneth Foote, information and education specialist for the U.S. Fish and Wildlife Service’s Division of External Affairs, in a phone interview Wednesday. “But, you just can’t really say anything until the final results get in.”
Final results are expected within two to three weeks. But evidence has already shown that diphacinone, the toxic element found in rodenticide, was not present within the “freshly found” fish that washed ashore on both islands, which are located northwest of Kaua‘i.
Dr. Thierry Work, wildlife disease pathologist with the National Wildlife Health Center, released preliminary data from a gross necropsy he administered to an adult male trigger fish, or humuhumu, collected Feb. 2 on Ni‘ihau.
He found that there were “no visible external lesions” and “no evidence of external or internal bleeding,” although the fish had a “pale liver and swollen swim bladder,” said Don Heacock, marine biologist for the state Department of Land and Natural Resources Aquatics Division on Kaua‘i.
Heacock also mentioned that there was no inflammation, which would typically suggest the presence of an infectious disease.
“The animal died rather quickly. However, of all the fish I saw, they did not die at the same time,” he said. “Maybe they all died quickly, but at different times.”
Heacock said that some fish may had been dead for many days, while others, only a few hours. He suggested that further investigations continue before any concrete explanations are given.
“We are submitting the tissues for microscopic examination to see if we can detect cell abnormalities,” he said. “That may shed more light on the issue. We are also asking for rush processing.”
Heacock believes it’s possible that further investigations will reveal diphacinone, but he has “strongly suggested” that the National Water Quality Assessment Program conduct further tests which would encompass numerous pesticides, chemicals and other “abnormalities.”
“We have only been looking for the active ingredient, diphacinone, but we don’t expect they’re going to find it,” he said.
Keith Robinson, a family owner of Ni‘ihau, said “there has never been a fish kill off like this” on the island. He said he doubts it’s a coincidence that the fish washed ashore days after the rat poison was air-dropped.
“It’s an awful coincidence,” he said Wednesday. “The Ni‘ihau community is pretty upset and angry about this situation and I don’t blame them one bit.”
He explained that they will forgo fishing, one of their primary means of acquiring food, until further evidence proves the fish to be free of possible contamination.
Robinson has had previous personal experience using rodenticides and claimed that they can have “unintended consequences.”
“I’m certain they can have side effects that we don’t know about,” he said.
Robinson has also expressed concern for the monk seals which frequent Lehua, saying that they recently seemed almost “comatose.”
“The bottom line is we don’t know and we are very suspicious,” he said.
Lehua, a crescent shaped islet just off the northern coast of Ni‘ihau and 20 miles west of Kaua‘i, is home to some 50,000 seabirds and 23 species of native plants. Officials say rats have been causing a threat to the bird sanctuary and the plants, insects and seeds vital to the Hawaiian island ecosystem.
According to a press release in October 2008, the U.S. Fish and Wildlife Service and the state DLNR Division of Forestry and Wildlife concluded that diphacinone would be “an effective toxicant for rats in Hawai‘i” and “is preferred because it is less toxic to nontarget species (such as birds) than other rodenticides.” They said in a written statement that it would “provide a net benefit to native species and their habitats on Lehua.”
Foote said a strict protocol was adhered to when administering the toxicant last month.
“The bait was applied based on specific protocol by helicopter and we assure very little gets into the ocean and is monitored very closely,” he said. “The amount that actually gets into the water is minimal.”
Foote said that the rodenticide has already been effective, although it takes two years before it can be deemed a “success.”
“Rats are highly destructive,” said Foote. “They have been there for a considerable amount of time.”
State Department of Health public information specialist Judy Kern did not have any information to add as of Wednesday afternoon.
“I do know that there is an investigation of what may have been the cause of the fish deaths, but there is nothing conclusive yet,” she said.
Deborah Ward, DLNR information specialist, said the public will be informed “when we have some results back and interpretation.”
Attempts to contact Wendy Goo, spokesperson of NOAA, for an update into the cause of the humpback whale deaths were unsuccessful.
