Nevada’s endangered desert pupfish are spawning after Alaska’s earthquake sent waves reverberating around their watery home.
Earlier this week, Alaska's magnitude 7.9 earthquake triggered a small tsunami. Waves only three to eight inches tall washed in along shores from British Columbia through California. But the shaking also rippled across the continent, setting off waves in Devil’s Hole, an 18-foot-long pool that branches deep into the Nevada aquifer. The sloshing water was reflected in the pool, building into waves—also known as a sieche—over a foot tall, Abby Wines writes in a statement for Death Valley National Park. The seiche didn’t cause any damage, but it did disrupt the pool's most famous inhabitant, the desert pupfish, causing the creatures to unseasonably spawn.
Desert pupfish usually spawn during the spring and the fall but any disruption of their environment can spark another spawning event, biologist Ambre Chaudoin tells Wines. The males turn a brilliant blue when they spawn, while the females are a subdued grey to silvery blue.
Devil's Hole pupfish (Cyprinodon diabolis) are critically endangered and live only in Devil’s Hole. Though this limestone cavern dives over 400 feet deep below the Mojave Desert, the inch-long fish live in just the upper 80 feet of the pool. The fish eat algae that grows in a shallow sunlit shelf at the top of the hole, and spawn on a tiny shallow shelf.
The creatures have survived in this environment for thousands of years, depending on its steady oxygen concentrations and a constant temperature of 93 degrees Fahrenheit. But the situation is precarious; small interferences could cause the conditions of this delicate ecosystem to rapidly change, devastating the pupfish. Their population had hovered around 400 to 600 fish until water levels in the pool dropped due to nearby irrigation. Park biologists only found 115 fish during the last survey, Wines writes, up from 38 fish during a 2006 survey.
Park staff aren’t concerned that the seiche and unexpected spawn will cause any lasting damage. “The pupfish’s food source will probably be a little reduced for a bit, but it is expected to rebound,” Chaudoin tells Wines.
“It’s crazy that distant earthquakes affect Devils Hole,” ecologist Kevin Wilson tells Wines. “We’ve seen this a few times before, but it still amazes me.” Similar seiche were observed in 2010 and 2012.
In 2010, Chaudoin was at the pond performing pupfish behavioral surveys as part of her graduate research, and managed to film an approximately 4-foot-tall seiche triggered by a magnitude 7.2 earthquake in Baja California. “The shelf substrate sediment was largely redistributed as a result of the water oscillations,” she said at the time in a statement from the US Geological Survey. “Such disturbance can be important because the spawning shelf is less than 13 feet long and 7 feet wide, smaller than many walk-in closets.”
Peter Byrne was at Devil’s Hole during the 2012 seiche, and wrote about the event for Scientific American. Then, too, it triggered a pupfish spawn, leading Byrnes to tease, “environmental disaster, it seems, acted as an aphrodisiac.” A video of the seiche went viral, and currently has over a million views.
During the 2010 seiche, biologist Paul Barrett hypothesized that the infrequent events played an important role in refreshing the Devil’s Hole ecosystem. “Earthquakes, such as a 1978 temblor in Mexico, can set up waves that clear the spawning shelf of the algae upon which the pupfish rely, however depending upon the time of year, the algae may regenerate quite rapidly,” Barrett said in the USGS statement. “Furthermore, quakes can serve a useful purpose in shaking silt and other fine particles that have washed into Devils Hole off of the spawning shelf and into the deeper waters. This frees important space between the substrate particles where the Devils Hole pupfish larvae seek refuge.”
Not every earthquake sets off a mating frenzy. The earthquake needs to be just the right frequency for waves to resonate. But with pupfish populations low, perhaps this latest seiche will help create a population boom.
Editor's note January 31, 2018: This article has been corrected to show that Devil's Hole pupfish is a species of desert pupfish exclusively found in Devil's Hole.