05-31-2009, 11:15 AM
All of the trout in New Mexico's McAllister Lake, a popular fishing spot near Las Vegas, have reportedly died as the result of hot summer temperatures and an accidental diversion of water.
"McAllister Lake is really on the threshold for trout in New Mexico," says Eric Frey, Northeast Area Fisheries Manager. "Because the lake is so shallow, summer heat causes marginal water quality for trout survival."
The fish kill was reported to the Department of Game and Fish on June 22. An investigation determined that high water temperatures and low oxygen levels likely killed all the trout in the lake.
So what led to this disaster? Several factors, including natural and man-made problems.
Each year a water allotment is diverted into McAllister Lake from the Storrie Lake Project, but this year personnel changes in the Department caused a miscommunication and no water was requested from the Storrie Lakes Water Users to be released into the lake. Lower than usual water levels meant that warmer summer days quickly made warmer water.
However, biologists said that even with the additional water, a fish kill may have occurred this year.
One reason trout have thrived in McAllister Lake is an elaborate aeration system installed in 1989 designed to provide enough dissolved oxygen to avoid frequent fish die-offs during hot summer months. The system of air pumps and hundreds of feet of tubing continually stirs the lake and keeps the oxygen levels high enough for trout survival.
To protect the aeration system's tubing, the Department of Game and Fish does not allow boat anchors in the lake. However, year after year biologists find the tubing pulled and tangled by anchors. On shore, all-terrain vehicles damaged the system lines, and rodents infested the aeration pump house. Replacing the system is an expensive effort that could be damaged again by a few illegally placed boat anchors.
This year the Department also began receiving complaints about too many carp in McAllister Lake. Anglers reported that they were catching nothing but carp. Biologists found that the carp not only were an irritation to some anglers but also apparently were contributing to a decline in the aquatic vegetation. The vegetation acts as habitat for smaller fish, filters the water and helps improve the water's clarity. The Department removed 400 carp from the lake this year, but huge numbers remain.
Any effort to remove carp from the lake will be addressed in a step-wise approach that could include netting, fish toxicants, and allowing the lake to dry.
McAllister Lake has been a very popular fishing spot for many years. It was stocked with bass and other warmwater fish until the late 1940s, when the Department began to stock trout. From 1997 to 2004, the Game and Fish Department estimated angler use from 18,413 to 49,926 angler visits a year. McAllister has ranked in the top 50 waters statewide for angling use. With proper management and a working aeration system, the lake can provide good growth rates for trout.<br />
Department of Game and Fish biologists and administrators will be working on a plan of action this winter with hopes of making improvements to the lake as soon as possible. Funding and water will be key issues in determining how soon McAllister Lake will be back in the fishing report and producing trout for anglers' creels.
For more information about McAllister Lake, please contact the Department of Game and Fish Northeast Area Office in Raton, (505) 445-2311.
"McAllister Lake is really on the threshold for trout in New Mexico," says Eric Frey, Northeast Area Fisheries Manager. "Because the lake is so shallow, summer heat causes marginal water quality for trout survival."
The fish kill was reported to the Department of Game and Fish on June 22. An investigation determined that high water temperatures and low oxygen levels likely killed all the trout in the lake.
So what led to this disaster? Several factors, including natural and man-made problems.
Each year a water allotment is diverted into McAllister Lake from the Storrie Lake Project, but this year personnel changes in the Department caused a miscommunication and no water was requested from the Storrie Lakes Water Users to be released into the lake. Lower than usual water levels meant that warmer summer days quickly made warmer water.
However, biologists said that even with the additional water, a fish kill may have occurred this year.
One reason trout have thrived in McAllister Lake is an elaborate aeration system installed in 1989 designed to provide enough dissolved oxygen to avoid frequent fish die-offs during hot summer months. The system of air pumps and hundreds of feet of tubing continually stirs the lake and keeps the oxygen levels high enough for trout survival.
To protect the aeration system's tubing, the Department of Game and Fish does not allow boat anchors in the lake. However, year after year biologists find the tubing pulled and tangled by anchors. On shore, all-terrain vehicles damaged the system lines, and rodents infested the aeration pump house. Replacing the system is an expensive effort that could be damaged again by a few illegally placed boat anchors.
This year the Department also began receiving complaints about too many carp in McAllister Lake. Anglers reported that they were catching nothing but carp. Biologists found that the carp not only were an irritation to some anglers but also apparently were contributing to a decline in the aquatic vegetation. The vegetation acts as habitat for smaller fish, filters the water and helps improve the water's clarity. The Department removed 400 carp from the lake this year, but huge numbers remain.
Any effort to remove carp from the lake will be addressed in a step-wise approach that could include netting, fish toxicants, and allowing the lake to dry.
McAllister Lake has been a very popular fishing spot for many years. It was stocked with bass and other warmwater fish until the late 1940s, when the Department began to stock trout. From 1997 to 2004, the Game and Fish Department estimated angler use from 18,413 to 49,926 angler visits a year. McAllister has ranked in the top 50 waters statewide for angling use. With proper management and a working aeration system, the lake can provide good growth rates for trout.<br />
Department of Game and Fish biologists and administrators will be working on a plan of action this winter with hopes of making improvements to the lake as soon as possible. Funding and water will be key issues in determining how soon McAllister Lake will be back in the fishing report and producing trout for anglers' creels.
For more information about McAllister Lake, please contact the Department of Game and Fish Northeast Area Office in Raton, (505) 445-2311.