December 12, 2012
Colorado's liquid gold, our water, typically makes the news because of its importance to the metropolitan areas and the agriculture of several states which depend on it for irrigation. At least two other interests that don't expend the water, leaving it for its primary use get less publicity but are contributors to the economy. Boating and water sports is one; the other is the fishing in lakes and streams all over the state.
This time of year the Colorado Department of Parks and Wildlife (CPW), previously known as the Division of Wildlife, is actively engaged in the gathering of the spawning kokanee salmon to collect eggs and sperm from the dying fish to restock the fishery in the spring. The fish, which are cousins to the sockeye salmon of the Pacific Northwest turn orange, with the males developing the same hooked upper jaw as their relatives as they approach the age of 4 years and move toward their spawning beds.
The kokanee are not native but were introduced first in Lake Granby in 1952, the year the lake formed behind a dam completed the year before. In following years, the fish were stocked in Willow Creek, Green Mountain, Wolford and Williams Fork Reservoirs, all in Grand County, and Dillon reservoir in Summit County where they are both a prey and a game fish.
In order to effectively harvest the fish, nets are placed to direct the fish into a trap from which they can't escape. A dip net is used to retrieve the fish from the water into tubs. Jon Ewert, aquatics biologist for the state for this area and his volunteers extract eggs and milt on scene, and within a couple of minutes the fertilized eggs are washed to help separate out the few that don't "take" (those turn white while the healthy fertilized eggs are a plump and healthy orange) and then placed in the type of beverage cooler used by football teams. Rainbows, cutthroats and other game fish that stray into the trap are released back into the water. White suckers are kept and given to anyone wanting them for bait. Also a non-native fish, the suckers got their start as minnows used as live bait and released by fishermen at the end of the day. The first 60 kokanee taken are kept for disease and other testing, and the remainder are divided among licensed fisherman who show up and put their name on a list.
The state hatchery in Glenwood Springs has a goal of 2 million kokanee eggs each year. Eggs above that goal go to the Rifle Falls Hatchery to produce additional fish. Once at the facility, the eggs are placed in shallow trays and incubated with minimal interference for about 30 days. Another check for bad eggs or other issues, and the eggs incubate for about another 30 days before they begin to hatch. For the next approximately five months, they live inside the hatchery until as fingerlings of 1.5- to 2-inches they are re-introduced to the lakes from which the eggs were taken, at least as much as possible.
What sounds like a straight forward procedure isn't quite that simple. The kokanee is not a dependably self-sustaining fishery, and it's the only one in which the fish die after spawning. The bodies of water in which they are stocked also contain rainbows, the ever hungry pike and lake trout and others who enjoy using small fish as food.
The largest potential danger to the fishery at the moment is the continuing and seemingly deepening drought that will impact all the fisheries. After record-breaking snowpacks in the winter of 2010-2011, the high country lakes began this last irrigating season at capacity. But with the minimal snowpack of this last winter, the lakes are very low, already creating less than optimal conditions for the fish. With the decreasing surface areas in late summer the top layer of water became too warm for the fish. Too little oxygen to sustain the fish in the lake bottoms left them trapped in an ever-narrowing layer of water in ever-shrinking bodies of water.
So far, it appears the kokanee harvest at the Williams Fork will be nearly non-existent this fall with the first attempt at netting producing only 67 fish. Wolford has been adequate, and Lake Granby is expected to allow the goal of 2 million eggs to be reached.
Then the waiting begins, not so much for the eggs to hatch but for the winter season, which will hopefully produce enough runoff in the spring to replenish water levels in the reservoirs. Without adequate runoff, the fishery, as well as recreation and agriculture will be in serious trouble. ❖