Biologists put otters through sniff tests.

Byline: Winston Ross The Register-Guard

It's been a tough morning for Aialik, the scent-sniffing sea otter.

He's spent a good portion of it squabbling with his pool-mates, Hunter and Adaa. Since arriving here from Alaska five years ago, Aialik has found himself at the bottom of the Oregon Coast Aquarium's otter hierarchy, and he's desperately trying to scrap his way into second place.

But the time has come to focus on the task at hand. Wielding a "target," a long wooden dowel with a red-and-white buoy on the end, senior marine mammalogist Ken Lytwyn leads the young otter to a board with the numbers `0' and `1' displayed on it, and a hole the size of a quarter in the center, revealing the spout of a plastic tube.

Behind the board and a chain-link fence sits Jennifer Hammock, a graduate student from Woods Hole Oceanographic Institution, in Cape Cod, Mass. Hammock is testing Aialik's sense of smell, which scientists have historically written off as useless or unimportant in marine mammals.

But the student and her self-designed "olfactometer" are determined to prove otherwise, with a research project that could eventually be used to create otter repellent, helping animals like Aialik avoid hazards such as oil spills.

Using a steady enticement of shrimp and clams, Lytwyn is teaching Aialik how to demonstrate the power of his nose. In only a few weeks, Aialik learned to stick his nose in the hole and sniff. If he smells something, he's to move his nose to the 1. If not, he points to 0.

Hammock manipulates a series of dials on the chrome-colored briefcase-shaped olfactometer to send air from a scuba tank through a chamber with today's sample in it - vinegar.

Sometimes she blows nothing but air. Other times it's a pungent odor. It's Aialik's job to figure out which is which.

After one right answer, Aialik gets distracted. He sniffs, but then bobs his head left and right - "goofing," as Lytwyn describes it. The otter is frustrated.

"Ah, not my finger, turkey lips," as the animal nips at his trainer. "You've got to do this - for the good of the species. Sniff. Nooo. Sniff. OK, let's take a break."

They try again in a few minutes, but Aialik, still seething from his tiff with Hunter, won't cooperate. He's whining, growling, reaching for nonexistent fish in Lytwyn's hand, climbing up on the sign.

"Down, Godzilla," Lytwyn says. Aialik complies, sniffing the hole.

"OK, now gimme an answer. Yes."

"It was a no," Hammock says. She put nothing in the hose for Aialik to smell.

The 4-year-old northern sea otter is being a troublemaker today, but he's actually the first to complete his training of the nine otters Hammock selected from across the country for the study. She started this project a few years back, in her second year of graduate school.

While some of her classmates studied the sense of hearing, Hammock's supervisor suggested researching an otter's sense of smell.

Until now, scientists had assumed that smell is an unimportant sense in marine mammals, who often forage for food using their other senses. While similar studies have examined the sniffing ability of a dozen other mammals, none have taken on marine mammals.

Sea otters have a complicated nasal cavity, with a sizable amount of surface area, which is probably used for air conditioning and reclaiming heat more than for sniffing things, Hammock said.

But the surface area and the size of an otter's olfactory bulb also suggests a keen sense of smell, much greater than that of humans, who have one of the poorest senses of smell among mammals. So Hammock set out to test the animals.

She won't be able to determine how important an otter's sense of smell is. The only way to do that would be to surgically remove it, and that won't happen with a federally protected species.

But Hammock hopes to learn how sensitive an otter's sense of smell is. That could be helpful in determining how strong of an odor is necessary to keep them away from hazards - or from raiding shellfish hatcheries.

She contacted aquariums around the country to see who'd be willing to participate, and the Newport staff signed on.

As Hammock built her olfactometer, Lytwyn puzzled over how to teach an otter to sniff on command.

"When this was first proposed, I thought, `No way am I going to teach a male sea otter to do this,' ' Lytwyn said. The otter's first encounter with the sniff board was to dismantle it. Not a good beginning.

But Lytwyn started over. A common first step in marine mammal training is to get them to "target," so he taught the animal to put his nose wherever the trainer put the target. Then, it was a matter of convincing Aialik to put his nose in the hole and sniff. Since Lytwyn could hear the sound reverberating in the hose, he rewarded the otter whenever it sniffed.

For the next few weeks, Lytwyn taught Aialik to move his mouth to the 0, with nothing behind the hole to smell. He did this by rewarding the otter for sniffing and then moving his target to the O.

Then Lytwyn put bottles of something smelly behind the hole and started teaching Aialik to move his head to the 1 in that case. After a few weeks there, Lytwyn started switching back and forth. Eventually, the clever otter figured it out.

He has his good days and bad days, Lytwyn and Hammock say. It took awhile to refocus Aialik once he figured out that he could see through the board if he stuck his eye up to the hole, or that he could make music by tapping his paw against it.

But with food as an incentive, Aialik gets most of the answers right, when he's feeling cooperative.

CAPTION(S):

Aialik receives a chunk of seafood as a reward to reinforce his success in a recent scent-testing session at the Oregon Coast Aquarium.