NOV 09, 2017

Study: Beluga Whales Consuming Fewer Greenland Halibut, More Forage Fish

WRITTEN BY: Anthony Bouchard

Climate change can have a more substantial impact on animals around the globe than we realize, and a new study published in the journal Biology Letters this week by researchers from the University of Manitoba underscores this sentiment.

The study deliberates how climate change affects beluga whales and one of their favorite types of prey: the Greenland halibut. While the former often munch on the latter, both ocean-dwellers share a mutual prey: a forage fish known as capelin (Mallotus villosus).

Image Credit: Werner22Brigitte/Pixabay

Decades worth of ocean life data indicates that the ocean’s warming waters are driving vast amounts of fish northward into Arctic waters, where they find the optimal water temperature. Many forage fish then end up in beluga whale territory, giving the whales less of a reason to seek and devour Greenland halibuts.

“These findings show how Arctic predators are responding and adjusting to climate change,” said study lead author David Yurkowski.

“These adjustments can modify the dynamics of the food web in many complicated ways, with consequences that reverberate across the entire Arctic food web. It's possible the entire structure and function of the Arctic food web is dramatically changing.”

Related: Can whales change their environments?

If you’re a Greenland halibut, then this is good news for you because beluga whales have a more significant abundance of forage fish to eat instead. In fact, these ecological changes could cause Greenland halibut populations to explode in coming years, which could help spur the commercial fishing industry.

On the other hand, not all ecological changes are taking a turn for the best. Animal experts now need to consider how increased forage fish predation will impact the fragile balance of the natural food web. Even the smallest imbalance could trigger a chain reaction that echoes across the planet’s oceans.

Animal experts must now ponder the details about how these changes could impact the food web. There will inevitably be a few short-term changes, but the bigger question is what will happen in the long-term when forage fish populations begin to dip too low.

Future studies may present some insight as researchers continue analyzing how ocean life responds to climate change. Until then, anyone's guess is as good as ours.

Source: CBC, Phys.org