Experts believe a badly deformed humpback whale recently spotted off Kauai has scoliosis, or curvature of the spine.

David Schofield, marine mammal response coordinator for the National Oceanic and Atmospheric Administration, provided information at a news briefing yesterday on the signs of a whale in distress.

At about 9:30 a.m. Monday, a white, emaciated whale with a severely deformed spine was photographed by a flight instructor off Port Allen, Kauai. The whale was last seen at 1 p.m. that day traveling west toward Waimea.

Following news reports, NOAA received dozens of calls of possible sightings, but all were of healthy mammals.

Schofield said officials are confident the whale has scoliosis, a defect the mammal was either born with or acquired over the course of its life.

He ruled out a boat collision.

"They’re not like cartoon animals," he said. "They don’t hold the shape of the contusion. Sometimes they’ll have like a little imprint, but it’s just not too plausible to see that if the animal had been impacted there that the peduncle or the tail shaft would’ve stayed that way."

Indicators of a distressed whale include a pale appearance caused by dying skin, and red patches on the skin from a proliferation of cyamids, crablike critters smaller than a pencil eraser.

Healthy whales have a smooth body texture and are black to slate gray or light gray.

It is considered normal for single whales or a mother and calf to swim close to shore, Schofield said.

Whales can be seen nesting in shallow water and as close as 100 yards to shore, he added. Nesting whales typically lie motionless at the surface of the water for extended periods of time, referred to as logging behavior.

Humpback whales migrate to Hawaii from Alaska to breed and give birth to their calves during the winter.

Schofield said the whale might be observed breathing often. However, an adult whale might hold its breath for 20 to 30 minutes, which is normal, he said.

If the distressed whale is spotted, Schofield requests the reporting vessel stay nearby until a team is deployed to monitor it.

Anyone with information on the location of the distressed whale is asked to call the NOAA hot line at 888-256-9840.