Native fish restoration resumes in Río Costilla watershed
State plans to use piscicide on nonnatives to restore cutthroat trout, close area to fishing for two years
The New Mexico Department of Game and Fish begins treating streams in the Río Costilla watershed Friday (Sept. 25) as part of a decades-long project to restore Río Grande cutthroat trout to its native waterways. The current project area will be closed to fishing for at least two years.
This fall’s treatment is the final phase of what is termed the Río Costilla project, which began in the early 2000s with an environmental review and public scoping process. The first treatments occurred in the upper Comanche Creek watershed in 2007-2009.
For this go-round, an estimated 25 stream miles will be affected within the Valle Vidal unit of Carson National Forest. No streams are being retreated, according to DGF spokesperson Gary “Cody” Johnston.
Streams scheduled for treatment include Costilla Creek from the Costilla Reservoir dam south to the western boundary of Valle Vidal; the lower section of Comanche Creek and its tributaries; Turner Creek, upper and lower La Cueva Creek, Blind Canyon Creek, Chuckwagon Creek, Fernandez Creek, Midge Creek and Powderhouse Creek.
The waters of Valle Vidal are designated collectively as an Outstanding National Resource Water because of their outstanding ecological and recreational values. They have the highest protection under the federal Clean Water Act.
Streams within Río Costilla Cooperative Livestock Association property are outside the project area, said Johnston, who is a DGF public information officer in southeastern New Mexico and was assigned within the past month as spokesperson for the Río Costilla project.
The livestock association did not respond to several requests for confirmation or comment before press time.
The work in the area will involve the application to streams of the chemical rotenone in liquid form. Rotenone is poisonous to fish and used to eradicate them completely in a stream system.
According to the Environmental Protection Agency, rotenone breaks down relatively quickly in the environment and does not present a risk of “unreasonable adverse effects” to humans or the environment. Other studies link the piscicide to neurological disorders in animals and humans.
The initial work for this phase of the project is expected to be complete by October 9.
Johnston said that five small teams will be camping in the area and will practice all COVID safety measures, including wearing masks and social distancing. Additionally, teams working with rotenone will wear protective gear as outlined in manufacturing instructions and required by the government agency.
He reported that Forest Road 1950, the main east-west route through Valle Vidal, will be open for travel, but public recreation activities in the project area will be closed.
MaryAnna Clemons, public affairs officer for the Carson National Forest, was unable to confirm any closures by press time.
Some barriers may be built as needed between treated and untreated sections of a stream. A neutralizing agent – the chemical potassium permanganate – will be added downstream so that fish outside the project area are not affected by the rotenone application. Potassium permanganate is sometimes used in water treatment plants to purify drinking water.
Once all fish have been removed and the stream tested and monitored over a period of time, native trout will be released back into it.
Fisheries biologists plan to reintroduce genetically pure strains of Río Grande cutthroat in the spring of 2022.
Río Grande cutthroat trout, one of 14 subspecies of cutthroat trout, is native to the Río Grande, Pecos River and Canadian River basins in New Mexico and Colorado.
Nongovernment organizations partnering with the project include Trout Unlimited and Turner Enterprises/Vermejo Park Ranch.
Closing streams to fishing may cause economic hardship to fishing guides, inns, and other local businesses in Taos as well as the surrounding areas of Costilla, Amalia, Garcia and Jaroso.
One such business is the Costilla gas station located at the intersection of State Road 522 and State Road 196, which also is at the crossroads for community news.
Alma Duran and her husband, Denecio, recently assumed ownership again of the gas station after a hiatus of five years.
As of last Friday (Sept. 18), Alma Duran was not aware of any planned stream closures in the watershed.
“Many anglers come here from all over the country,” she said. “Our business definitely will be affected.”
Nick Streit, owner of Taos Fly Shop in Taos and Reel Life in Santa Fe, is a well-known angler and guide.
He supports the reintroduction of the native cutthroat — “It’s a beautiful fish,” he says — but acknowledges that stream closures could adversely affect his business.
“If they’re closed for one year, that’s doable,” he said. “But three years? That really becomes a problem.”
Streit says he speaks regularly with legislators about the positive economic impact recreation, especially fishing, has on the state. He worries the Department of Game and Fish doesn’t receive the resources it needs to minimize the time of closure.
Johnston says that at no time since the Río Costilla project began have closures exceeded two years.
DGF reported in 2014 that the large scope of the project and its success rate kept the cutthroat off the federal endangered species list.
But why has the project taken so long?
Johnston says it’s a big project. The biggest of its kind in the country.
“By the time the project is completed, we will have treated 120 stream miles, ten lakes and the Costilla Reservoir,” he said.