Casey P. answered • 06/15/22
BS in Ecology, Evolution, and Behavioral Biology
Imagine you're at a restaurant that serves only soup, all you have to eat with is a fork, and you're miles and miles away from the next-nearest food joint. That's the situation blue whales may find themselves in if climate change gets much worse.
Let me back up and explain:
Blue whales' bodies themselves are fairly resistant to changes in water temperature (they have to be, since they migrate across multiple climates each year). Unfortunately, blue whales also have a very specific diet: they eat almost exclusively krill, and because of their specialized baleen "teeth," can't easily adapt to eating other foods.
Antarctic krill are impacted heavily by polar ice, which is melting much more rapidly due to climate change. Already, populations of Antarctic krill are only 70-80% of what they once were, and they are moving further and further south with each year. In short, blue whales' food supply may move or disappear, and their specialized features will make it very hard for them to find other options.
Blue whales also seek out specific breeding grounds during specific seasons so that they can give birth to their more-fragile babies (called calves) in gentler waters. Changing ocean temperatures could force them out of their historic breeding grounds.
Blue whales might not be the absolute worst-off animals in a climate disaster, as they could potentially change their migration habits and feeding locations to adjust. But changing migration patterns is difficult and may not work out in their favor. There are other factors at play here, but if you're talking about inherited whale traits, this is the most important bit: blue whales' highly specialized feeding abilities and habits make them vulnerable to climate change.
