FORT COLLINS, CO – It was still dark out when I threw the thermos of coffee into the truck and left Denver for the Zimmerman Lake Trailhead just east of Cameron Pass. The goal for the day was to join two other fellow TU volunteers and work alongside Colorado Parks and Wildlife (CPW) biologists to help with Greenback Cutthroat spawning at the pristine high alpine lake. Since 2013, CPW and Colorado Trout Unlimited have worked together to establish a population of Greenback broodstock up at Zimmerman Lake that can be used to help populate other streams throughout the cutthroat’s native range. The recent spawning project took place over four days and engaged a handful of CPW staff along with eight CTU volunteers from various Front Range Chapters.
The spawning process was pretty straightforward and designed by CPW staff to expand the genetic pool of Greenback Cutthroat Trout. The pictures below highlight much of the process that took place over the four days. A big THANK YOU to all the volunteers who came out to support this important recovery effort!
CPW set up at the Zimmerman Lake inlet to capture spawning Greenbacks.
Fish were collected with a large net and put into a pen to be sorted and categorized by CPW staff and volunteers.
Fish were sorted based on their gender and stocking year.
RFID chips in the fish help to identify the stocking year and other critical data.
After the fish were sorted, CPW milked the males and females - making targeted genetic crosses among the various lineages to expand the genetic diversity. The eggs and sperm were combined in bowls, packed into small coolers, put on ice, and shipped to the local fish hatchery in Leadville, CO for breeding.
This process is a critical step in the long-term recovery of the native Greenback Cutthroat Trout. CTU is proud of the great work that its volunteers provided during these long days up at the lake. The work undertaken at Zimmerman will help ensure that future fishermen and women are able to chase these rare fish throughout the Front Range for decades to come.
For more information on the project or to get involved with other upcoming Greenback recovery projects, contact Dan Omasta, CTU Grassroots Coordinator (domasta@tu.org).
