Given that caribou are herbivores, it seems possible that populations in the Arctic might actually benefit from climate change—there'd be more green stuff around for them to eat. Well, no. A team of researchers has released a new study finding the changes to vegetation that come with melted sea ice seem to put the animals' food sources in danger.
Lead researcher Per Fauchald, research manager at the Norwegian Institute for Nature Research, said he and his team originally thought caribou could stand to benefit from a greening Arctic. In fact, caribou populations may very well decline in the face of climate change, as they'll face increasing pressures. It's bad news for the Indigenous communities that rely on them.
Animation of annual sea ice concentration, summer greening on the Arctic tundra and the development of caribou populations from 1982-2011. Herd population fluctuations over time are depicted by growing and shrinking caribou symbols. Image: Per Fauchald
Caribou are herbivores, feeding on grass, herbs and lichen. A greener Arctic would theoretically mean more food, he said in a Skype interview. "We found that what was the opposite of what was happening."
The team studied over 35 years' worth of population data on 11 herds of caribou moving across North America, from Alaska to Labrador. They found no evidence of large herds eating the vegetation supplied by a greener Arctic. In fact, sea ice is connected to more summer pasture plant growth, and maybe a drop in caribou populations—possibly because different kinds of shrubs are now spreading, with toxins that caribou typically avoid.
Mark Boyce, an ecology professor at the University of Alberta who was not involved in this new research, published a paper in 2009 on the global decline of caribou and reindeer.
"Caribou numbers go up and down, and that's always happened," he said in a phone interview. "But, what's really disturbing about the recent trend, over the last few decades or so, is there are declining populations everywhere and there are very few herds anywhere that are actually increasing."
"'Shrubification' is happening," Fauchald said, of the changes now taking place to Arctic vegetation. This is where small shrubs are expanding into the tundra, while grass and herbs that have historically grown there are being taken over.
Boyce has studied the socioeconomic impact of this loss on northern Indigenous cultures, for whom the caribou hunt is important.
"[Some] Inuit peoples, as well as northern First Nations, really depend on Caribou," said Boyce. "It's their lifeblood for meat and they use the hides."
In 2016, Nunavut Arctic College Media published a book about Inuit Elders observing climate change. The book, titled The Caribou Taste Different Now, details how climate change has impacted local food sources. In excerpts in Nunatsiaq Online, Inuit Elders said that caribou are disappearing. Where the animals can still be found, they appear skinnier, like they're sick.
"This is the problem with climate change," said Fauchald, citing the scarcity of data around its impacts on caribou. "It's hard to predict the future because we've never seen anything like this before."
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