by Corinna Hanson
A chest of gold coins, sparkling diamonds and goblets crusted with rubies are just some of the images that come to mind when I hear the word treasure. But the treasure found on Baca NWR is not precious metals or gems, but two rare native fish, the Rio Grande sucker, one of only two naturally-occurring populations in the entire state of Colorado, and the Rio Grande chub, a state species of concern.
One day, while on a refuge tour, refuge manager Ron Garcia spotted some fish swimming in a pool along a culvert outlet. Since it was unknown what fish species existed on the refuge, Garcia asked the Colorado Parks and Wildlife (CPW) to conduct baseline sampling. In 2006, CPW conducted electroshocking surveys and determined that Baca NWR had a community of native fish, including fathead minnows, longnose dace, and the rare Rio Grande sucker and Rio Grande chub. When Ron received the news from CPW that the refuge had a healthy population of these rare species, he was astonished! Who would have thought that a ditch system on an old ranch would contain such a treasure?
CPW electroshocking during a fish survey on Baca NWR
Since its establishment in 2003, the purpose of Baca National Wildlife Refuge (NWR) has been to restore, enhance, and maintain wetland, upland, riparian, and other habitats for native wildlife, plant, and fish species in the San Luis Valley. For over 120 years, prior to the refuge’s establishment, most of the property functioned as a working cattle ranch. With the refuge’s many miles of creeks, ditches and canals, approximately 9,000 acres of meadows were irrigated annually, creating valuable wetlands for wildlife. The creek systems on the refuge are mostly ephemeral, fed by snowmelt from the adjacent Sangre de Cristo Mountain range. However, on a few of the creeks, there are stretches of perennial water that begin and end on the valley floor.
In the first years of establishment, Garcia relied on the advice and expertise of Eddie Clayton, a rancher and irrigator who had worked on the property for over 40 years. Clayton is a rancher with a sharp wit and coarse sense of humor. When Garcia told Clayton about the discovery of the Rio Grande chub and sucker Clayton exclaimed, “Shoot, I was afraid you would say something like that. I thought they were rare, but didn’t want to tell you since we used to use Rio Grande suckers for mackinaw fishing bait.”
I’m happy to say that we’ve come a long way since the days when the ranchers used Rio Grande suckers for bait. In 2013 and 2014, both the Rio Grande chub and Rio Grande sucker were petitioned for protection through the Endangered Species Act. Refuge staff has worked hard to forge and maintain partnerships to promote the conservation of these rare fish species. The Fish and Aquatics Branch of CPW continues to support and assist with native fish conservation on the refuge and conducts fish surveys at sampling locations that have been in place for almost 10 years. These long-term sampling efforts have provided essential information on the Rio Grande sucker and Rio Grande chub population, including presence, age class, and overall health of the population.
In 2013, we formed a valuable partnership with the U.S. Fish and Wildlife Service’s Colorado Fish and Wildlife Conservation Office (CFWCO) in Denver. Thanks to this collaboration, our conservation objectives for these fish have evolved from basic monitoring to more in-depth research, habitat improvement, and population management. Through the partnerships with CPW and CFWCO, we have been able to improve fish sampling methodology, evaluate and address entrainment issues, conduct research to identify barriers to fish movement, repair fish passage problem areas, monitor water temperature and baseflow in fish habitat, and implement a pit tag study to estimate population numbers, assess movements, and approximate survival rates. These research projects provide important information regarding the health of the population and the habitats that they are using and help guide fish habitat improvement and restoration projects on the refuge.
The partnerships with CPW and CFWCO are an excellent example of how working together towards a common goal can result in greater successes than any one agency or organization can achieve on their own. Without these partnerships and their additional resources, the status of the Rio Grande sucker and the Rio Grande chub on the refuge would likely still be unknown. Although there are multiple challenges associated with conserving rare fish in an irrigation system, the future appears bright for these rare treasures on Baca NWR.
We would like to thank the following people for being great partners: Pam Sponholtz (Project Leader, CFWCO), John Alves (Senior Aquatic Biologist, CPW), Paul Jones (Aquatic Biologist, CPW), and Ben Felt (CPW).