Penn Vet Pathologists Uncover the Fate of Stranded Marine Mammals

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Media Contact:Katherine Unger Baillie | | 215-898-9194April 13, 2012

Perry Habecker’s claim to fame? He’s the only Pennsylvania pathologist to have autopsied a “Pennsylvania” manatee.

The distinction is not incidental; dissecting and studying dead marine mammals is just part of the job for Habecker, chief of the Large Animal Pathology Service at the University of Pennsylvania School of Veterinary Medicine’s New Bolton Center campus, and for his colleagues.

Through a partnership with the Marine Mammal Stranding Center in Brigantine, N.J., New Bolton’s veterinary pathologists perform necropsies of dolphins, seals and small whales that do not survive after stranding along the Jersey shore.

Vets, residents and senior students at Penn Vet complete about two dozen marine mammal necropsies each year. After taking measurements of each animal and recording its weight, they follow a standard necropsy procedure, examining the creature’s skin, blubber, head and brain and other internal organs.

To pick up on abnormalities in an animal’s body during a necropsy, said Julie Engiles, an assistant professor of pathology with Penn Vet, she uses her senses of sight, touch, smell and hearing.

The vets follow up with microscopic analysis of bodily tissues to look for parasites and other indicators of disease.

Animals that strand tend to be undernourished, signaled by a thinner-than-normal blubber layer.

“Either there is not enough food, they don’t feel well enough to eat or they have a disease that prevents them from hunting or obtaining food,” Engiles said.

Often the vets cannot definitively identify a specific cause of death but find heavy parasite loads or signs of poor nutrition. Death from pneumonia is also not uncommon for marine mammals.

But sometimes, the cases are a bit more unusual.

Take Habecker’s wayward manatee. In the fall of 2008, it wandered up the Delaware River and, caught in the cool November waters of Pennsylvania, lacked the energy to return to its native Florida. Cause of death? A combination of hypothermia and energy depletion.

Engiles has her own memorable necropsy. In “our most CSI-like case,” she recalled, a short-finned pilot whale beached itself near Asbury Park and died shortly thereafter. The whale was taken to New Bolton Center, where Engiles found a wound that extended from the animal's head to its shoulder. Upon deeper examination, they realized they were looking at a gunshot wound.  

“We found that there was a bullet lodged in his skull,” Engiles said.

The unfortunate whale suffered from the injury for a month before succumbing at the shore. Although a reward of $2,500 was posted for information leading to the shooter, the culprit has not been identified.

The vets look for less dramatic evidence of human influence on the lives of marine mammals as well.  

“We’re always alert for human interactions, that is, if they have injuries from boats or fishing nets, or if they’ve ingested any human junk,” Habecker said. “I save plastics [consumed by the animals] whenever I find them.”

While the primary intent of these necropsies is to identify the reason the animals perished, a close second is to advance scientific understanding of these sometimes-mysterious creatures of the sea.

“That’s the high-minded goal of all of this,” Habecker said.

The vets keep a working list of researchers who might have a use for certain body parts or tissues from the necropsied animals. In one case, they’ve worked with Smithsonian Institution scientists studying the middle and inner ears of beaked whales to determine whether they had suffered injuries from the use of sonar in the oceans. In another, they’ve cooperated with a West Chester University scientist who analyzes the flow of water over anatomical structures like fins.

And for New Bolton Center vets themselves, dissecting whales and seals can be an invigorating change from their more typical work with horses and cows.

“There’s always something new in terms of anatomic features or disease processes to discover,” Engiles said. “I’ve honestly learned something new in my job every day.”