Would Finding Nemo's Nemo have found his dad if he couldn't hear? Probably not! Which is why it's so sad that all of the Nemos out in the ocean (technically, they're called "adorable baby clownfish") are going to lose their hearing, and therefore their sense of when it's time to swim as fast as they can away from predators.
Obviously it's all humanity's fault. More carbon dioxide in the atmosphere means higher ocean acidity, which interferes with the Nemos' ear bones. Scientists found that Nemos reared in water simulating the predicted carbon dioxide concentrations for 2050 and 2100 had no response whatsoever to predator noise.
Probably not a good idea to tell the kids that when they want to watch their favorite Pixar movie for the gazillionth time, they're contributing the inevitable deaths of Nemos everywhere.