The end of a trout stocking era

By the Nevada Department of Wildlife
Sometime in mid-March the Nevada Department of Wildlife (NDOW) will release the last load of rainbow trout for the agency’s annual stocking season at Lake Mead and Lake Mohave.

But unlike years past, the release of these final truckloads of fish will mark more than the end of a trout stocking season.

They will mark the end of an era, the end of NDOW trout stocking efforts along the Lower Colorado River.

The beginning of the end started in January 2007 with the discovery of quagga mussels in the Lower Colorado River System and shortly thereafter in the Lake Mead Fish Hatchery.

Coupled with high water temperatures associated with dropping water levels, the quagga mussels were the proverbial straw that broke the camel’s back and ultimately led to the hatchery’s closure.

NDOW could not risk moving mussels from the hatchery to other state waters through its trout stocking efforts.

“We have a couple of issues at Lake Mead. One is the lake has dropped more than 100 feet and the Basic Water Company water intake is now less than 40 feet below the surface, which means that we get our water at warmer temperatures — above 70 degrees in July and August. And that’s just too warm to raise trout,” said Mark Warren, NDOW Fisheries Chief. “So we have the warm water issue and, of course, the main one is that we have a quagga mussel infection. As a result we shut down the hatchery.”

Following the Lake Mead Hatchery’s closure in spring 2007, the Willow Beach National Fish Hatchery offered NDOW the use of a few of its raceways as well as net pens submerged in the cold waters of the Colorado River.
Since then, the trout NDOW has released in Lake Mead and Lake Mohave each winter have been raised at this facility. However, NDOW has chosen to discontinue this practice due to logistics and escalating costs.

In addition, “We’ve lost a lot of shoreline too. The places that are shallower – we call them littoral zones – where the trout would hold after being stocked. Now we’re stocking the fish and they don’t hold where anglers can catch them. Instead they move out of the area quicker than in the past, so it just became monetarily and otherwise impossible to stock the fish anymore. So the decision was made to stop stocking trout,” Warren said.

Though NDOW will no longer be stocking trout in Lake Mead or Lake Mohave, the agency hopes the program can be revived by reopening the Lake Mead Fish Hatchery at some point in the future.

“Our hope is that sometime in the future we can get it up and running again. The Southern Nevada Water Authority is building a new intake that will draw water from 200 feet below the surface of Lake Mead, and they’ll ozonate it and chlorinate it. If we were able to tap into that water supply that would enable us to bring the hatchery back online, but there also would be significant costs associated with doing so. All that will need to be considered as we move forward,” said Warren.

In the past NDOW has hauled in trout purchased from hatcheries located in Oregon, but that effort had mixed results.

“Due to the logistics of hauling purchased fish all the way from Oregon this is really not a viable option. Not only is this very expensive, but it’s a very long haul and the fish did not travel well. So we didn’t get much of a return on those fish. It really is a no-win scenario,” Warren explained.

Even though NDOW will no longer stock trout in Lake Mead and Lake Mohave the agency will continue to stock the Las Vegas area urban ponds and the popular fisheries in nearby Nye and Lincoln counties.
Those include Eagle Valley Reservoir, Echo Canyon reservoir and the impoundments at the Kirch Wildlife Management Area.

In addition, the Willow Beach National Fish Hatchery will continue its weekly trout plants at Willow Beach.

Although NDOW will no longer be stocking trout at Lake Mead, anglers will continue to benefit from excellent catch rates on other game fish species such as smallmouth bass, largemouth bass and striped bass.
The average catch rate at Lake Mead was 3.9 fish a day in 2010. That includes all species of fish. In 2009, 86 percent of the fish reeled in by anglers were striped bass.

Thanks in part to the arrival of gizzard shad, the body condition of striped bass may be the best it has been for some years, according to fisheries biologists, the fish averaged 16.5-inches in the catch in 2010.