HONOLULU — Scientists investigating last month’s stranding of five pilot whales on Kauai’s Kalapaki Beach have ruled out disease as the cause of the beaching.

The scientists said something sudden must have triggered the stranding, but they’re still not sure exactly what caused the whales to beach themselves, the Honolulu Star-Advertiser reported Wednesday.

The whales beached themselves Oct. 13. Two died in the morning and three were found dead later in the day.

The Navy reported it did not conduct sonar work within 24 hours of the event, within 5 nautical miles (9 kilometers) of the area. And marine mammal experts said the whales did not show signs of trauma from underwater noise impacts, such as gas bubbles in their blood vessels or organs to indicate decompression sickness.

“We often find animals that are very skinny and look nutritionally stressed, and that was not the case with any of these animals,” said Kristi West, stranding director at the University of Hawaii’s Hawaii Institute of Marine Biology. “This was pretty surprising for us for strandings: All five of our animals had full stomachs, and that’s somewhat unusual, because typically if we have a single stranding or an animal is sick, it hasn’t eaten.”

West said several test results are still pending, including neurotoxin screenings to test for poisons that affect the nervous system, testing of liver tissue for rodenticides and microscopic examinations of the whales’ inner ears.

“The fact that all these animals had so much food and the freshness of the food just tells us that something sudden happened that brought them in,” she said. “That’s what we kind of have right now for hints as to what happened to the whales. . This was something sudden.”

State Rep. Dee Morikawa, a Democrat, said she’s been researching whether the stranding was linked to the state’s deployment of rat poison on Lehua Island.

The state Department of Land and Natural Resources in August and September dropped pellets containing diphacinone on the rat-infested island.

There are an estimated 19,500 pilot whales in the waters surrounding the main Hawaiian Islands, including resident populations that stay in certain areas and open-ocean groups.


Information from: Honolulu Star-Advertiser, http://www.staradvertiser.com