A species of fish once declared extinct has not only survived but is expected to thrive thanks to a five-year effort to restore habitat and translocate more than 700 Owens pupfish.

In early April biologists from the California Department of Fish and Wildlife (CDFW) and U.S. Fish and Wildlife Service, Reno Office (USFWS) moved the pupfish from five different habitats in the Owens Valley to the River Spring Lakes Ecological Reserve in Mono County. These fish, once surviving in under an acre of habitat, now have several square miles of marsh to live in. Prior to the translocation, CDFW completed the removal of non-native fish from the reserve to ensure the future of the pupfish.

“This release represents the culmination of years of dedication and hard work by numerous former and current biologists,” said CDFW Fisheries Supervisor Russell Black. “This population will become the largest and most genetically fit population of Owens pupfish since World War I and is a great victory for conserving the species.”

“The translocation of a mix of Owens pupfish from five other populations to this new habitat creates optimism that the future for pupfish is bright,” said Marc Jackson, USFWS field supervisor. “Partners in the Owens pupfish recovery effort are planning additional translocation projects to restore them to more sites within their historic range.”

CDFW biologists Nick Buckmaster and Rosa Cox, along with USFWS biologists Kaylan Hager and Andy Starostka spent two days trapping, measuring and collecting Owens pupfish from the five extant populations. Once the desired number of males and females were gathered at each site, the pupfish began their hour-long trip to their new home. Buckmaster, the project’s leader, recently revisited the reserve to check the progress of the fish and was pleased with what he found.

“They’re spawning successfully,” said Buckmaster. “This introduction is an important step toward securing Owens pupfish against extinction and ensuring the continued existence of one of the most imperiled fish species in North America.”

Imperiled is a fitting word when describing the Owens pupfish. The species was declared extinct in 1940, then rediscovered in 1964 near Bishop only to face extinction again in 1969 when legendary fishery biologist Phil Pister saved the pupfish days before their habitat would dry up. Buckmaster says Pister’s essay on the subject titled ‘Species in a Bucket’ is commonly read by biology students and is one of the most downloaded articles from Natural History Magazine.

“Since 1969, the species has been on life support, tenuously occupying a couple acres of habitat,” said Buckmaster. “This restoration provides the first opportunity for us to introduce Owens pupfish into habitat that is both stable enough to support them for the long haul and large enough to support a robust population in 100 years. This is a major win for a decades-long project to rescue Owens pupfish from extinction.”