While the tsunami warning for California’s December 5 magnitude 7.0 earthquake was eventually lifted, that’s not to say the quake didn’t cause waves elsewhere. Roughly 805 kilometers (500 miles) away from the epicenter, in a cavern that is part of Death Valley National Park, the critically endangered Devils Hole Pupfish (Cyprinodon diabolis) saw its watery home quickly and drastically change.
Life in Devils Hole is normally pretty still; it’s a geothermal pool at the bottom of a collapsed cave and as such, it’s sheltered from wind that could otherwise move it.
However, according to a statement from the National Park Service (NPS), at approximately 10:46 am local time – two minutes after the earthquake struck – the water in Devils Hole began to shake.
This created waves – known as seiches when they occur within an enclosed body of water – which reached nearly 60 centimeters (24 inches) high. Their movement was enough to disturb the main spawning area of the Devils Hole Pupfish, an IUCN Red List critically endangered species that is only found in the wild in its namesake habitat.
While biologists from the NPS, Fish and Wildlife Service, and Nevada Department of Wildlife are still figuring out how the waves may have impacted the fish, there have been some initial suggestions.
“In the short term, this is bad for the pupfish,” said NPS biologist Dr Kevin Wilson. “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.”
Devils Hole before (top) and after (bottom) the seiche.
Image credit: NPS
That might sound like a poor prognosis for the future of this critically endangered species, but Wilson explained that it’s not all bad news.
“[I]n the long term, this type of reset is good for the pupfish. It cleaned off any decaying organic matter that could otherwise cause pockets of low oxygen,” said Wilson.
That may be why the pupfish has survived and even increased in number after previous seiches, some of which were caused by earthquakes as far away as Mexico and Alaska. In fact, earlier this year, a survey revealed a 25-year high in the number of Devils Hole pupfish during the spring season and most recently, the population was observed to stand at 212.
While the Devils Hole pupfish may well recover from this most recent seiche event too, they still face multiple threats, including from human activity and climate change.