SUPERIOR, Ariz. — More than 450 endangered desert pupfish are once again swimming in Ayer Lake at the Boyce Thompson Arboretum, marking a major milestone in Arizona’s native fish conservation efforts.
The Arizona Game and Fish Department (AZGFD) successfully restocked the lake on March 26, following a year-long absence due to dam repairs that required the lake to be drained.
Kim Gray, executive director of Boyce Thompson Arboretum, said the team is proud to work with AZGFD to protect the endangered pupfish, calling the species an important part of the ecosystem and noting that Ayer Lake is an ideal habitat for them.
A Safe Return with New Neighbors
While the lake was under repair, AZGFD kept the pupfish safe in tanks and a greenhouse pool, where they even produced offspring. For the restocking, fish from two other refuge sites—Cottonwood Tank at Robbins Butte Wildlife Area and the Phoenix Zoo Aviary pond—were also added to the mix.
Brett Montgomery, AZGFD’s topminnow and pupfish specialist, said he was excited to get the fish back into the lake, calling it a great habitat where the pupfish will have a strong chance to thrive.
Superior Mayor Mila Besich participated in the release, saying it was a memorable experience and adding that the community is proud of the Arboretum’s sustainability efforts and AZGFD’s role in wildlife conservation.
Why Pupfish Matter
Desert pupfish help maintain healthy ecosystems by eating mosquito larvae and managing aquatic vegetation. Though small—usually under three inches—the males put on a stunning show during mating season, turning bright blue with yellow tails and aggressively defending territory.
Montgomery explained that the pupfish bring real benefits to the Arboretum and emphasized how important it is to avoid introducing non-native species to the lake. He noted that even one invasive species could undo all the restoration efforts and force the recovery process to start from scratch.
What’s Next? Gila Topminnow
AZGFD also plans to introduce endangered Gila topminnow to Ayer Lake once the pupfish have had time to adjust.
Gray said the Arboretum is home to abundant wildlife and that the staff intentionally designs garden spaces to support native species. She added that they’re looking forward to growing their partnership with AZGFD in the future.
