Thursday’s 7.0 magnitude earthquake in Humboldt County was felt across the Bay Area and all the way to the Nevada-California border, where it also rattled the remote cave habitat of one of the rarest animals on Earth.

Two minutes after the earthquake hit, water began to slosh about 500 miles from its epicenter in Devils Hole, the home of the critically endangered pupfish deep within the Mojave Desert, a news release from the National Park Service read. Scientists estimate the disturbance caused rare waves up to nearly two feet high, which churned the normally still water in the pool of the cavern, disrupting the shallow rock ledge that serves as the species’ primary spawning area.

“In the short term, this is bad for the pupfish,” National Park Service biologist Dr. Kevin Wilson said in the news release. “A lot of pupfish food just sank deeper into the cave, most likely too deep for the fish to get to it. There were likely pupfish eggs on the shelf that were destroyed.”

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The phenomenon that struck their habitat is known as a seismic seiche, which occurs when water oscillates from one side to another of an enclosed body of water. They're most commonly caused by strong winds or dramatic changes in atmospheric pressure, but they can also be driven by seismic waves, which happened in this event.

Fortunately, there could be some positive benefits in the long-term, Wilson said. Decaying organic matter was swept into the depths of the 500-foot cavern where the fish live, possibly providing a kind of “reset” that otherwise could have contributed to low oxygen levels in the water.

That’s not to mention the hardy inch-long pupfish, named for the way they appear to frolic as they swim, have survived similar events, including when a 7.6 earthquake in Mexico triggered four-foot-tall waves in the limestone cave in 2022. Earlier in 2019, another 7.1 earthquake caused the water to rise and fall at least 10 to 15 feet, the park service said. The year prior, a 7.9 earthquake originating from the Gulf of Alaska produced waves up to a foot high.

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“It’s crazy that distant earthquakes affect Devils Hole,” Wilson said at the time. “We’ve seen this a few times before, but it still amazes me.”

In the past, the fish have responded by increasing their spawning activity, which the park service doesn’t consider to be abnormal. That said, a team of researchers from the NPS, the U.S. Fish and Wildlife Service, and the Nevada Department of Wildlife are evaluating ways to mitigate disruptions on the fish at the only location in the world where they can be found.

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The species experienced a recent comeback, with 212 pupfish recorded during the most recent count in September. Just over a decade ago, there were only 35 of them. The pupfish continue to be carefully monitored as they face other threats to their population, such as groundwater pumping and climate change. Wilson said experts likely plan to increase the amount of supplemental food provided to the fish, which primarily consume algae.