A rare Uroglena bloom in Beaver Lake, Arkansas, spring 2015

摘要

Green WR, Hufhines B. 2017. A rare Uroglena bloom in Beaver Lake, Arkansas, spring 2015. Lake Reserve Manage. 33:8-13.A combination of factors triggered a Uroglena volvox bloom and taste and odor event in Beaver Lake, a water-supply reservoir in northwest Arkansas, in late April 2015. Factors contributing to the bloom included increased rainfall and runoff containing increased concentrations of dissolved organic carbon, followed by a stable pool, low nutrient concentrations, and an expansion of lake surface area and littoral zone. This was the first time U. volvox was identified in Beaver Lake and the first time it was recognized as a source of taste and odor. Routine water quality samples happened to be collected by the US Geological Survey and the Beaver Water District throughout the reservoir during the bloom. Higher than normal rainfall in March 2015 increased the pool elevation in Beaver Lake by 2.3m (by early April), increased the surface area by 10%, and increased the littoral zone by 1214 ha; these conditions persisted for 38days, resulting from flood water being retained behind the dam. Monitoring programs that cover a wide range of reservoir features, including dissolved organic carbon, zooplankton, and phytoplankton, are valuable in explaining unusual events such as this Uroglena bloom.