Most importantly, Asian clams, unlike the zebra mussel, are incapable of destroying Lake Tahoe. Quagga mussels have been found at depths of up to 540 feet in Lake Michigan where they filter feed year round.Consequently, quagga mussels may end up being the more problematic of these two mussel species in California. QUAGGA/ZEBRA MUSSELS What are quagga/zebra mussels? These mussels were most likely Zebra/quagga mussels, unlike the Asian clam, have thin shells and their shells are not asymmetrical like those of the Asian clam. Similar observed effects between zebra and quagga mussel filtration suggest that quagga mussels could also contribute to this impact. Although the quagga mussel closely resembles its cousin, it is not expected to have as great an impact on native mussels because it does not show a preference for using them as substrates. Goals / Objectives Two of the biggest threats to the structure and function of NewYork lakes are climate change and invasive species, in particular two species of dreissenid mussels - the zebra mussel (Dreissena polymorpha) and the quagga mussel (Dreissena rostriformis bugensis). A Menace to the West • ACTIVITIES assessment Questions (with answers following) 1 How could you tell the difference between a zebra and quagga mussel? How big are quagga/zebra mussels when compared to native mussels? The quagga is a close relative of the zebra mussel and is very similar in appearance and in environmental and economic impact. Sometimes they are larger, sometimes they are microscopic. Zebra mussels are found throughout all the Great Lakes, Lake St. Clair and the Mississippi river watershed. Since the 1980s zebra mussels have spread throughout much of the eastern United States. Both species attach to rocks, sand, silt or each other by producing tiny but strong “byssal” threads, string-like strands of protein. Sometimes they are larger, sometimes they are microscopic. Although both zebra and quagga mussel populations have most likely peaked—the zebra mussel around 1989 and the quagga mussel between 1998 and 2002—another invader, the round goby, has been preying on selected benthic groups, continuing to affect the composition of the community. Problem. The zebra mussel is triangular in shape, with one flat edge that allows it to stand on its ventral side without falling over; For But there are just as many seagulls and people visiting the beaches, so that’s not likely the answer. Zebra mussels also prefer warmer water temperatures and do not grow as big as quagga mussels. Zebra and quagga mussels likely made their way to the Western USA on trailered watercraft. Unlike the zebra mussel, quagga mussels are found to be limited to the southern Great Lakes; Lake Ontario, Michigan, Huron and Erie. Those are invasive mussels that made their way from Eastern Europe, likely in the ballasts of cargo ships. Zebra (Dreissena polymorpha) and quagga (D. bugensis) mussels cost the U.S. economy up to $1 billion each year. However, seasonal effects were unlikely to contribute to any differences in the mechanical detachment force between zebra and quagga mussels By 2008, mean density of Lake Michigan quagga mussels … Invasive zebra and quagga mussels (collectively called dreissenid mussels) are causing significant ecological and economic impacts and the range of these impacts continues to increase as they spread across North America. Zebra and Quagga Mussels Aquatic Invasions! This is consistent with our assumption that both species have the same survival term ϕ(t) due to competition for food. Unlike the zebra mussel, quagga mussels are found to be limited to the southern Great Lakes; Lake Ontario, Michigan, Huron and Erie. Those are invasive mussels that made their way from Eastern Europe, likely in the ballasts of cargo ships. A Menace to the West • ACTIVITIES assessment Questions (with answers following) 1 How could you tell the difference between a zebra and quagga mussel?