Quagga

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In response, the California Department of Fish and Game immediately created a multi-agency task force that included Metropolitan Water District as one of its members.

Within a few days after the initial discovery, divers from Fish and Game, the U.S. Fish and Wildlife Service and Metropolitan plunged into the waters of lakes Mead, Mohave and Havasu. It only took minutes for MWD divers to make the first verified discovery of quagga mussels in California, in the Lake Havasu waters at Whitsett Intake plant. Clinging to concrete surfaces and anchors about 40 feet below the surface at Metropolitan’s pumping plant, the mussels were now a threat to the Colorado River Aqueduct that serves Southern California.

Quaggas were found in lakes Mead and Mohave as well.

The question was—why?

Experts quickly realized that prior to 2007, the previous hunts had focused on the zebra mussels, which tend to favor shallower depths. These quaggas were found in deeper, darker waters about 35 to 40 feet below the surface.

Metropolitan divers later uncovered quaggas in the pumping plants and washbasins at the east end of the system, at the beginning of MWD’s Colorado River Aqueduct. They were small colonies of young quaggas, more than 200 miles from the nearest MWD reservoir.

U.S. Fish and Wildlife biologists looked at the data, and concluded at that time that the infestation was in its very early stages – possibly two years from causing any serious issues.

Mussel-encrusted bait bucket Lake Oologah, Okla. Photo by David Britton, Ph.D. U.S. Fish & Wildlife Service.

But the quagga had outsmarted them. Unknown to the country’s top quagga experts, the warmer temperatures of the western United States were to prove much more hospitable than they realized.

The first sign came during a routine shutdown in March, which doubled as a quagga-scouting mission. The mussels had encroached 20 miles into the aqueduct, but were still in small quantities. Metropolitan crews dried out the aqueduct, then applied shock chlorination when the water began flowing again.

By June, the quaggas had spread more than 125 miles into the aqueduct, showing up at some of Metropolitan’s pumping plants along the way and beginning to thrive at the east end of the aqueduct. Now the experts realized that the quaggas were growing and reproducing much faster than they realized – and that there had been a spring spawning season in lakes Mead and Mohave.

Metropolitan shut down the entire aqueduct in July to dry out the mussels and kill them. During the shutdown, the quaggas were discovered at the entry points to Lake Mathews, the reservoir at the end of the aqueduct, as well as Lake Skinner, an MWD-owned reservoir that fills with Colorado River water. In response, Metropolitan went to 24-hour-a-day chlorination.

Like any drawn-out conflict, the first steps focused on surveillance, and learning how to detect and analyze the enemy. Metropolitan staffers quickly developed an expertise in detecting baby quaggas (known as veligers), and learned how to detect the mussels through water analysis.

	Photo by Bob Pitman U.S. Fish & Wildlife Service.

Toward that end, Metropolitan convened a meeting of the U. S. Fish and Wildlife Service, state Department of Fish and Game, federal Bureau of Reclamation, California Department of Water Resources, Los Angeles Department of Water and Power, and the city of San Diego. In addition, Southern Nevada Water Authority and Portland State University (the laboratory for the 100th Meridian Initiative) also attended and discussed their monitoring programs.

“Controlling the spread of this mussel in our water system is a top priority for us,” Metropolitan Chief Operating Officer Debra Man said. “We plan to take every action necessary to protect and maintain the reliability of our aqueduct, lakes, pipelines and other facilities.”

Managing the mussel invasion has become a nationwide effort involving state Fish and Game, plus the Fish and Wildlife service, enlisting scientists from the Center for Lakes and Reservoirs of Portland State University, the Great Lakes Water Institute, and the Reclamation bureau.

Quaggas also began showing up at other Southern California lakes, including reservoirs in San Diego County.
By late summer, Metropolitan was allocating millions of dollars toward upgrading its chlorination facilities at its key reservoirs, and redesigning the Colorado River Aqueduct to allow portions to be shut down for spot treatment operations without requiring shutdown of the entire aqueduct. Metropolitan staff and construction services staff were working diligently with the water quality section to implement and further develop control programs.

Photo by David Britton, Ph.D. U.S. Fish & Wildlife Service

It was part of a larger integrated strategy where the tools might range from deterring mussels from attaching to surfaces, or enlisting predators or parasites in a biological control program, or altering the temperature or pH within reservoirs to keep mussels under control. Microbiologists at Metropolitan’s nationally-known water quality lab quickly learned how to dissect quagga mussels, hovering over microscopes, taking pictures and determining which quaggas had reached the reproductive stage. They began setting up a laboratory that will be devoted exclusively to the study of quaggas, and their behavior in Southern California reservoirs.

Because the quaggas most likely traveled west via boat trailers, among the most important members of the anti-quagga coalition has been the boating public itself. Metropolitan quickly began training marina staff and operators on how to inspect and decontaminate boats.

It reflects a wider statewide concern that boaters might inadvertently introduce the quagga mussel into bodies of water throughout the state. Staff began working with the California Department of Water Resources to establish a monitoring and response program.

Along with the response within California, Metropolitan began working with the U.S. Fish and Wildlife Service (the agency with jurisdiction over the river) to establish a Colorado River Quagga Mussel Coalition in conjunction with the Arizona Department of Water Resources, Southern Nevada Water Authority and the Coachella Valley Water District, among others.

“Quagga mussels are going to be a serious issue for all of us for a long time,” Man observed. “This is going to be one of those battles that require everyone’s cooperation and understanding.”

	Boaters can help prevent spread
	• Remove any visible mud, plants, fish or animals • Before leaving an area, drain water from your boat, trailer, tackle and gear. Clean and dry anything that came in contact with water (boats, trailers, equipment) • Never put plants, fish or animals into a body of water unless they came out of that body of water • Consider more aggressive cleaning of your boat if it has been at a lake with known nuisance species
	More information about quagga mussels: 100th Meridian Initiative California Department of Fish and Game