As her assistants look on, Dee Boersma, the acting chair of the UW biology department, draws attention to the features of a penguin she has affectionately dubbed Bondo.

Boersma’s article in the newest edition of BioScience suggests that declining penguin populations indicate the unhealthy state of the world’s oceans.

Boersma points to the wings, which lie flat against the sides of Bondo’s body, and to his feet, which extend outward as if in mid-stroke underwater.

“You can see how heavy he is,” Boersma said while cradling the model penguin. “That’s why we call him Bondo — because he’s full.”

Bondo may not be a real penguin, but the real-life birds he was designed to mimic have been at the center of Boersma’s research for a quarter of a century. During a typical year, Boersma may take two or three trips to the narrow peninsula of Punta Tombo in Argentina, home to the largest colony of Magellanic penguins in South America.

Under her guidance, a small group of researchers track individual penguins and groups of penguins to collect data as part of the Magellanic Penguin Project. The project was created 25 years ago in response to a Japanese company that intended to turn the penguins into golf clubs, meat and oil.

But throughout the life of the project, and on its silver anniversary, researchers have been confronted by another problem — declining penguin populations.

The Magellanic penguin population is decreasing at a rate of 10 percent per decade, according to Boersma’s essay.

In October 2006, the population of the largest breeding colony at Punta Tombo had declined by nearly one-quarter from 1987 levels, Boersma wrote. In addition, the number of erect-crested penguin breeding pairs on the Antipodes Island in 1995 totaled about half of what they were in 1978.

While there are multiple explanations for the downward trend of penguin populations, including climate change, Boersma said the biggest threat to temperate species of penguins is humans, who continue to degrade the oceans.

“The human population is now at 6.8 billion people,” Boersma said. “Never in all of human history have there been that many people. The cost of having this many people and this much consumption is that we’re having amazing effects on our planet.”

In 2001, 30 shrimp boats dumped plastic, propane tanks and cardboard into the water near Punto Tombo, according to Boersma’s Web site. In the early 1980s, Boersma and her researchers estimated that more than 40,000 penguins died each year because of the dumping of petroleum-tainted water by oil tankers.

“[Penguins] have to spend a lot of time swimming,” Boersma said. “So if there’s oil in the water, it’s not like they can fly over it and not land in the oil. They have to go through it.”

In her study, Boersma explained that as fishermen continue to “fish down the food chain” for smaller fish, such as sardines, anchovies and squid, penguins are forced into competition with humans.

Olivia Kane, a program assistant who works with Boersma, is planning her third trip to Argentina in November, when penguin chicks hatch. She hasn’t noticed the decline firsthand, but she said there is a stark contrast between the penguin populations in old photographs and what they look like now.

“[Boersma] has pictures of certain areas that have tons of penguins, and now you don’t ever see that kind of density there,” Kane said. “We can look at her pictures and say, ‘Yeah, that’s not the way it is now.’”