How are they impacting the environment and the economy?
Zebra mussels have caused major ecological and economic problems since their arrival in North America, and quagga mussels pose much of the same threats. Quaggas are prodigious water filterers, removing substantial amounts of phytoplankton and suspended particulate from the water. By removing the phytoplankton, quaggas in turn decrease the food source for zooplankton, therefore altering the food web. Impacts associated with the filtration of water include increases in water transparency, decreases in mean chlorophyll a concentrations, and accumulation of pseudofeces (Claxton et al., 1998). Water clarity increases light penetration causing a proliferation of aquatic plants that can change species dominance and alter the entire ecosystem. The pseudofeces that is produced from filtering the water accumulates and creates a foul environment. As the waste particles decompose, oxygen is used up, and the pH becomes very acidic and toxic byproducts are produced. In addition, quagga and zebra mus
