01-11-2007, 08:10 PM
A day that Lake Mead biologists and water officials have dreaded arrived Wednesday with confirmation that invasive zebra mussels have infested part of the lake.
The discovery raises concerns that the non-native nuisance mollusks will clog water pipes, affect hydroelectric power operations, ruin boat engines and spread to waterways throughout the West.
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"The implications are huge," said Kent Turner, a wildlife biologist and chief of resource management for the National Park Service at Lake Mead National Recreation Area.
"We're under way with an experiment about what the ecological conditions are in Lake Mead that may support the growth of zebra mussels and the densities that can exist," he said.
Southern Nevada Water Authority spokesman J.C. Davis said the authority is working with the National Park Service to get divers and cameras down to the two drinking water supply intakes at Saddle Island to determine whether zebra mussels have reached those depths, 130 feet below the surface.
"They can colonize and plug up the raw water intakes if left unchecked," Davis said. "We're going to know within a few weeks, if not less."
Davis said that when the second intake was built a few years ago, it was equipped with a feed system to inject potassium permanganate in anticipation of chemical treatment being needed to kill zebra mussel colonies.
The first intake, built more than 30 years ago, is not equipped with a chemical feed, "but we could have one built if we need to," Davis said.
"We don't anticipate any effect on water delivery," he said.
National Park Service officials said live zebra mussels were discovered Saturday on a breakwater anchor cable at the Las Vegas Boat Harbor by a marina employee. He notified a monitoring program volunteer, Wen Baldwin, who checked samples and found what appeared to be more zebra mussels at the boat harbor and at Lake Mead Marina.
"We knew it was going to happen, but it really shouldn't have been this soon," said Baldwin, president of the Lake Mead Boat Owners Association.
Turner said tests confirmed the mollusks were zebra mussels. He said officials late Wednesday were expecting results from an independent laboratory to determine which one of two species they are.
On Tuesday, divers focused on Lake Mead's Boulder Basin to assess the extent of the problem. Turner said the greatest densities were found at between 25 feet deep and 40 feet deep, primarily at the Las Vegas Boat Harbor near the Hemenway ramp and on tire breakwaters, cables and concrete anchors for the marinas.
Bill Dickinson, superintendent of Lake Mead National Recreation Area, said his staff is "very concerned."
"We are taking immediate action, in cooperation and consultation with other resource agencies, to assess the extent of the problem and develop a management plan," Dickinson said in a statement.
Evidence suggests that the infestation began when live zebra mussels were brought to the lake about three years ago from an unknown source, Turner said.
"We certainly don't know ultimately how they got here," he said. "Certainly they got here either being live mussels on a boat trailer or other pieces of equipment from an area that previously had zebra mussels."
The mussels also can survive in a few inches of water in a boat's live well, bilge or in water from an engine's cooling system.
In 2004, a 54-foot houseboat from Kentucky was stopped from launching at Temple Bar after zebra mussels were found on its hull. Since then, rangers and volunteers have stopped other boats with zebra mussels from entering the lake.
Nevada Department of Wildlife spokesman Doug Nielsen, a former game warden who writes an outdoor column for the Review-Journal, said the department will be looking at options to stem or slow the mussels' movement.
"Right now, we're all taking a deep breath," he said. "Can they be stopped? At this point, nobody's found a way."
Up to an inch long, zebra mussels have caused billions of dollars in damage in the Great Lakes region and elsewhere in the Midwest and eastern United States by clogging intake pipes for water supplies and ruining boat engines. They were found in Lake St. Clair near Detroit in 1988 after being transported to the region in the ballast of a ship.
Bureau of Reclamation spokesman Bob Walsh said the agency staff in Boulder City will monitor intake structures at Hoover Dam to check for zebra mussels that could impact water conduits and hydroelectric power systems.
"We don't have any evidence they're at the dam yet," Walsh said. "We'll be taking a look."
Wednesday's announcement by the National Park Service sent ripples of concern through water supply and wildlife agencies on the West Coast, where officials fear wide-ranging economic and ecological impacts.
"We're obviously on high alert," said Steve Martarano, a spokesman for the California Department of Fish and Game.
He said California officials are working on a state response to the situation should the infestation spread downstream on the Colorado River system. They are bracing for the possibility that boats from Lake Mead will carry or have carried zebra mussels to other California waterways.
"We're looking at emergency regulations that could be enacted to ensure that vessels aren't coming or leaving with this invasive species on them," he said.
Congressional researchers have estimated that zebra mussels cost the power industry more than $3 billion primarily in the Great Lakes and Midwest region between 1993 and 1999. The impact on industries, businesses and communities has been more than $5 billion.
The discovery raises concerns that the non-native nuisance mollusks will clog water pipes, affect hydroelectric power operations, ruin boat engines and spread to waterways throughout the West.
Advertisement
"The implications are huge," said Kent Turner, a wildlife biologist and chief of resource management for the National Park Service at Lake Mead National Recreation Area.
"We're under way with an experiment about what the ecological conditions are in Lake Mead that may support the growth of zebra mussels and the densities that can exist," he said.
Southern Nevada Water Authority spokesman J.C. Davis said the authority is working with the National Park Service to get divers and cameras down to the two drinking water supply intakes at Saddle Island to determine whether zebra mussels have reached those depths, 130 feet below the surface.
"They can colonize and plug up the raw water intakes if left unchecked," Davis said. "We're going to know within a few weeks, if not less."
Davis said that when the second intake was built a few years ago, it was equipped with a feed system to inject potassium permanganate in anticipation of chemical treatment being needed to kill zebra mussel colonies.
The first intake, built more than 30 years ago, is not equipped with a chemical feed, "but we could have one built if we need to," Davis said.
"We don't anticipate any effect on water delivery," he said.
National Park Service officials said live zebra mussels were discovered Saturday on a breakwater anchor cable at the Las Vegas Boat Harbor by a marina employee. He notified a monitoring program volunteer, Wen Baldwin, who checked samples and found what appeared to be more zebra mussels at the boat harbor and at Lake Mead Marina.
"We knew it was going to happen, but it really shouldn't have been this soon," said Baldwin, president of the Lake Mead Boat Owners Association.
Turner said tests confirmed the mollusks were zebra mussels. He said officials late Wednesday were expecting results from an independent laboratory to determine which one of two species they are.
On Tuesday, divers focused on Lake Mead's Boulder Basin to assess the extent of the problem. Turner said the greatest densities were found at between 25 feet deep and 40 feet deep, primarily at the Las Vegas Boat Harbor near the Hemenway ramp and on tire breakwaters, cables and concrete anchors for the marinas.
Bill Dickinson, superintendent of Lake Mead National Recreation Area, said his staff is "very concerned."
"We are taking immediate action, in cooperation and consultation with other resource agencies, to assess the extent of the problem and develop a management plan," Dickinson said in a statement.
Evidence suggests that the infestation began when live zebra mussels were brought to the lake about three years ago from an unknown source, Turner said.
"We certainly don't know ultimately how they got here," he said. "Certainly they got here either being live mussels on a boat trailer or other pieces of equipment from an area that previously had zebra mussels."
The mussels also can survive in a few inches of water in a boat's live well, bilge or in water from an engine's cooling system.
In 2004, a 54-foot houseboat from Kentucky was stopped from launching at Temple Bar after zebra mussels were found on its hull. Since then, rangers and volunteers have stopped other boats with zebra mussels from entering the lake.
Nevada Department of Wildlife spokesman Doug Nielsen, a former game warden who writes an outdoor column for the Review-Journal, said the department will be looking at options to stem or slow the mussels' movement.
"Right now, we're all taking a deep breath," he said. "Can they be stopped? At this point, nobody's found a way."
Up to an inch long, zebra mussels have caused billions of dollars in damage in the Great Lakes region and elsewhere in the Midwest and eastern United States by clogging intake pipes for water supplies and ruining boat engines. They were found in Lake St. Clair near Detroit in 1988 after being transported to the region in the ballast of a ship.
Bureau of Reclamation spokesman Bob Walsh said the agency staff in Boulder City will monitor intake structures at Hoover Dam to check for zebra mussels that could impact water conduits and hydroelectric power systems.
"We don't have any evidence they're at the dam yet," Walsh said. "We'll be taking a look."
Wednesday's announcement by the National Park Service sent ripples of concern through water supply and wildlife agencies on the West Coast, where officials fear wide-ranging economic and ecological impacts.
"We're obviously on high alert," said Steve Martarano, a spokesman for the California Department of Fish and Game.
He said California officials are working on a state response to the situation should the infestation spread downstream on the Colorado River system. They are bracing for the possibility that boats from Lake Mead will carry or have carried zebra mussels to other California waterways.
"We're looking at emergency regulations that could be enacted to ensure that vessels aren't coming or leaving with this invasive species on them," he said.
Congressional researchers have estimated that zebra mussels cost the power industry more than $3 billion primarily in the Great Lakes and Midwest region between 1993 and 1999. The impact on industries, businesses and communities has been more than $5 billion.