NUNAVUT
Angeline McIntyre spent three weeks at Elu Inlet, Cambridge Bay, Surrey River and Kugluktuk this summer collecting lemmings with the goal of figuring out if they play a role in a large population decline among muskox.

University of New Mexico students Dianna Krejsa, left, and Donavan Jackson gather trapped lemmings Aug. 6 at Ovayok in the Mount Pelly area to study if they might be spreading a bacterial disease to muskox. - Navalik Tologanak/NNSL photo

"In the past five years, there's been a big decline. This is big. This is a lot of animals," said McIntyre, a PhD student in the Department of Ecosystem and Public Health at University of Calgary. "On Banks and Victoria Island, at one point they had half the world's muskox population, so if you've now lost half of half the world's muskox population, this is big . without being alarmist,"

McIntyre's interest lies in wildlife disease, "especially where disease is a conservation risk to wildlife populations."

Her doctorate involves investigating a bacterial disease called erysipelothrix rhusiopathiae in muskox. She is especially interested in how the disease spreads, both through time and geographically.

"Nobody knows how bad (the decline) is, but it does look like anywhere from 50 to 70 per cent on Banks and Victoria Islands."

There were dead animals in the Cambridge Bay and Surrey River areas, as well.

McIntyre said it's known these "die-offs," or "mortality events," are because of erysipelothrix rhusiopathiae.

"This is a disease that is world-wide, but it's usually a problem for pig production and some poultry, though it's been seen in every kind of animal. It's called diamond skin disease. It's very common. People who have pigs would know about it," she said.

The first sign of the disease is a rash.

"It seems to be fairly opportunistic. Some animals might just get the rash. They can shed it through their feces without too much of a problem most of the time. But one of the things that causes mortality events in livestock are stress events. Things like lightning storms or moving animals, these stress events happen and basically animals just drop dead."

In 2012, about 150 muskox were seen dead on Banks Island.

"All age and sex classes. They were in good body condition. They weren't starving. They just basically dropped dead on the tundra. This happened very, very fast," said McIntyre.

Erysipelothrix rhusiopathiae was found.

McIntyre's doctorate supervisor, Susan Kutz, participated in a paper discussing the mortalities caused by the bacteria.

McIntyre's research is intended to find out everything possible about the disease in the North. With that in mind, she hopes to determine if lemmings are the culprits, helping the erysipelothrix bacteria spread.

"We didn't know it was up there," she said about the disease. "It had never been seen that far north before. We're looking at how it got to the islands. We thought maybe something is carrying it up from the south," adding that along with the lemming study, she is collecting samples from snow geese.

"It's very much a hypothesis (a possible explanation) that something is maintaining (the bacteria) on the island. And that could be the lemmings."

McIntyre collected about 100 lemmings, and because the rodent has to die for her experiments she teamed up with other researchers.

"We wanted to get as much information from them as possible, so it was a multidisciplinary project. I am looking for erysipelothrix, Eric Hoberg from the U.S. Department of Agriculture was looking for parasites (worms) in the rodents. His research is in evolution and geographic spread of parasitic worms. Dianna Krejsa and Donavan Jackson (of the University of New Mexico) were preserving tissues, the skeleton and skins of rodents, so more research can be done in the future."

McIntyre said lemmings are very clean.

"They clean out their nests a lot. But when you find good lemming habitat, there's feces everywhere. That could be a route of transmission for the muskox if they're eating in the same area. It would be like an environmental contamination," she said.

It will be months before McIntyre gets the results from her samples.

Humans can pick up the bacteria, which will normally present as a rash. This has been seen in pig and fish processing.

"We have had no reports of people in the North contracting (the illness) from processing muskox meat," said McIntyre. "As I said, we don't know if muskox carry it and are normally fine and then due to a stressful event - like days when it is very hot, the high temperature could be a stressor - they become sick and die, or if they come in contact with it in the environment and suddenly die.

"People in the North will not, as far as I am aware, harvest animals that are dead."

McIntyre said, at the end of the day researchers are trying to figure out what is happening and why, especially since there isn't a lot of research on disease happening in the North at the moment.

"Things are changing, especially with climate change, we don't know what's going to happen. We don't know whether or not these outbreaks are climate-related or not. But it's one of the avenues we're going to try to tease away, because as things keep changing, diseases spread. Pathogens are spreading north."

McIntyre is also testing archived seal samples from Alaska to Greenland, and samples from as many muskox and caribou herds as she can get from freezers in wildlife offices across the North.

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