Potential Zebra and Quagga Mussels Impacts in Standley Lake
Zebra (Dreissena polymorpha) and Quagga (Dreissena rostiformis bugensis) Mussels • Both are an aquatic invasive species (non- native) • Very similar in impacts on water bodies • Grow to approximately 1 inch (Zebra mussels somewhat smaller) • The only freshwater mollusk species that attach via threads to hard surfaces
Background • Originate from eastern Europe (Caspian & Black Sea)
Zebra/Quagga Mussel Biology • Spawn one to two times per year in Great Lake • Each female can produce 1 million eggs per year • Seeing 3 times that in warmer Lake Mead Beer Can • Filter one quart of water per day/mussel
Biology • Fertilized eggs develop within a few days into free- swimming larvae called veligers • Settle onto hard surfaces and quickly attach with very strong bond • As dense as 700,000 per square meter
2008
2015
Impacts of Zebra Mussels Lake Winnebago, Wisconsin
Standley Lake as a Water Supply
Infrastructure Impacts… • Mussel attachment could interrupt basic water service • Some facilities have reported large reductions in pumping capacity and occasional shutdowns • They can move through pipelines and infest water treatment plant processes and equipment
Impacts to Water Treatment Plant Infrastructure Pipe clogged with Zebra Mussels Sampling Plates at Parker Dam, California a fter only six weeks
Standley Lake Outlet Structure (being lowered into lake during 2003 rehabilitation project)
Underwater Photo – Domestic Water Intake Parker Dam (CA) - February 21, 2008
Underwater Photo – Trash Rack Parker Dam (CA)- January 15, 2008
Standley Lake Outlet System Standley Lake Northglenn SL Dam WTF FRICO Release Thornton WTF WTF = Water Treatment Facility Northwest WTF = a Valve Semper WTF
Potential Costs to the City • Quagga/Zebra Mussel Risk Assessment and Treatment Study – HDR, 2010 • $8.26 Million Capital Costs • $2.5 Million Operations and Maintenance – 2009 $
Impacts on Lake Ecosystem • Filtering so much water makes it clearer • Clear water allows light to penetrate further • More light penetration to greater depths allows plants and algae to grow deeper than before
Further impacts • This also results in more bad algae, which create taste and odor problems. These are difficult and expensive to treat • Decomposing algae mats stink • Harbor e. coli and botulism – Hundreds of thousands of bird deaths in the Great Lakes
Zebra Mussel on Crayfish
Impacts to Boats
Recreation Impacts: • Rotting mussels and sharp shells on shorelines • Smelly algae blooms • Downstream impacts on Big Dry Creek and rivers and reservoirs downstream
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