UWindsor PhD candidate Dave Yurkowski has found evidence that Arctic ringed seals are shifting behaviour patterns to adapt to climate changes in the north.
“In some parts of the Arctic we are seeing big changes, including the ringed seals’ diet,” he says.
Under the supervision of Aaron Fisk, Canada Research Chair and professor with the Great Lakes Institute for Environmental Research, Yurkowski has found that with subarctic fish now moving into the Arctic, ringed seals are using these fish, as well as zoo plankton, as a new food source, instead of their normal diet of high energy Arctic Cod.
“You are what you eat when it comes to biochemistry,” says Yurkowski.
“This diet change is having long term effects and we are already seeing a change in body condition in some areas of the Arctic.”
Yurkowski chemically analyzes muscle and liver tissue to determine diet. By comparing diet data from the high-Arctic versus low-Arctic, he has found that fish consumption decreased with latitude where seals in the low-Arctic are smaller and skinnier than ones in the high-Arctic. He has also found that over time, ringed seals are increasing their niche size, which means they are using a wider variety of resources and this could possibly alter their place in the food chain.
He says that for the most part, sea ice has been in steep decline since the 1970s. Climate change is causing a domino effect for other aspects of the ringed seals’ way of life as well. In addition to dietary changes, such competitors as harp seals and harbour seals are moving into ringed seal territory and this means the ringed seals are competing for the same food source, especially at lower latitudes.
The researcher says it is crucial to get baseline information documented now so researchers can look for long-term trends. We need more research, but primarily it is most concerning to see the change in body condition and increased competition, says Yurkowski.
“There are no ringed seal abundance estimates, but when you talk to people living in these northern communities, anecdotally they are seeing a noticeable decline in population. The Arctic is like a key to climate change because it is a somewhat sensitive ecosystem. If we see drastic changes there, then we know it is just the first place that we will see them.”
Yurkowski’s research will appear in Oecologia webpage, under Highlighted Student Research, dedicated to highlighting exceptional research by students as lead authors.