Death of whale remains a mystery

A necropsy on a pygmy sperm whale found floating in the Pearl Harbor channel was inconclusive, a Hawaii Pacific University marine mammal expert said Sunday.

However, researchers were able to identify the whale as an adult female, said HPU associate professor Kristi West.

The university has sent tissue samples to mainland labs for further testing, including a tooth that could narrow down the animal’s age, West said.

West predicted last week that the procedure would turn up few clues.

"The animal was too decomposed," she said Sunday by telephone.

Pygmy sperm whales are a protected species under the Marine Mammal Protection Act.

While pygmy sperm whales seem to strand quite often in Hawaii waters, they’re rarely seen on the ocean surface and spend most of their time foraging at depths between 2,000 and 4,000 feet, according to a 2009 study by West published in the journal Marine Mammal Science in 2009.

Contractors doing work near a pier saw the dead whale in the Pearl Harbor channel and notified federal officials at about 8 a.m. Wednesday.

The whale, about 800 pounds and 12 feet long, was taken by the Navy to a dock at West Loch, then towed two miles to a pier at the National Oceanic and Atmospheric Administration facility on Ford Island, federal authorities said.

The carcass was lifted into a truck at about 12:30 p.m. and transported to Hawaii Pacific University facilities in Leeward Oahu. West performed the necropsy later Wednesday with a team of HPU graduates and undergraduates.

"It’s a poorly known species, but they seem to strand quite often," said David Schofield, marine mammal health and response manager with the National Marine Fisheries Service.

According to scientists, pygmy sperm whales, or Kogia breviceps, are the second most frequently recorded stranded cetacean species in Hawaii waters. The first are dolphins.

Some 35 strandings of pygmy sperm whales in Hawaii waters were documented between 1963 and 2008, according to the Marine Mammal Science study.

Schofield said strandings occur for a variety of reasons, including the ingestion of foreign debris, congenital defects at birth, old age and pathogens such as a virus.