Effects of Invasive Quagga Mussels (Dreissena rostriformis bugensis) on Chlorophyll and Water Clarity in Lakes Mead and Havasu of the Lower Colorado River Basin, 2007–2009

• Published in: Quagga and Zebra Mussels pp. 519 - 532
• Format: Book Chapter
• Language: English
• Published: United Kingdom CRC Press 2014; Taylor & Francis Group
• Subjects: Aquaculture & fishing: practice & techniques; Biodiversity; The hydrosphere; Dreissenid Mussels; Dreissena Rostriformis Bugensis; Ua Ry; Las Vegas Bay; Water Clarity; Lower Colorado River Basin; Chlorophyll Concentrations; Zebra Mussels; Colorado River; Quagga Mussel Population; Lake Havasu; De Ce; Virgin Basin; Colorado River Basin; Secchi Depth Transparency; Lake Mead; Au Gu; Invasive Quagga Mussels; Boulder Basin; Dreissenid Population; Fe Br; Increase Water Clarity; Quagga Mussels; Las Vegas Wash
• DOI: 10.1201/b15437-39
• ISBN: 143985436X; 9781439854365

Quagga mussels (Dreissena rostriformis bugensis) were found in the Boulder Basin of Lake Mead (Nevada-Arizona) in the lower Colorado River Basin on January 6, 2007, and the population continued to grow from 2007 through 2009. This study focused on ecological impacts of quagga mussels in Lake Mead, which is the largest reservoir by water volume in the United States. Annual chlorophyll a concentrations decreased signicantly during the post-quagga period (2007-2009) compared to the pre-quagga period (2002-2006) in Boulder Basin (−45%) and Virgin Basin (−20%), but not in Las Vegas Bay, Overton Arm, or Gregg Basin. Water clarity increased signicantly in Boulder Basin (+13%) in the post-quagga period, but not in other basins in Lake Mead. Although chlorophyll a concentration’s and water clarity changed in the post-quagga period, falling water levels and changes in nutrient inputs from wastewater treatment plants are also likely causes for these observations.