What happens to fish when they go over waterfalls?

Freefall into water is generally not a problem for a light, streamlined fish, but it all depends on the type and scale of the waterfall.

By Vandana Gupta

Asked by: Toby Ellis, by email

It depends on the waterfall. Fish bodies are streamlined and relatively light so a long fall into water isn’t usually a problem. Niagara River expert, Wes Hill, estimates that 90 per cent of fish survive the drop over Niagara Falls. But a waterfall that cascades over rocks, such as Yosemite Falls, will be fatal to all but the smallest fish.

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