Water Resources Research Act Program

Details for Project ID 2011CT226B

Testing Methods used for DNA Barcoding of Environmental Samples from the Eightmile River for Diatom (Bacillariophyta) Identification.

Institute: Connecticut
Year Established: 2011 Start Date: 2011-03-01 End Date: 2012-02-28
Total Federal Funds: $10,690 Total Non-Federal Funds: $21,420

Principal Investigators: Diba Khan-Bureau, Louise Lewis, Gary A. Robbins

Abstract: Microscopic algae, particularly diatoms, are accepted as biological indicators for monitoring and assessing watercourses. Diatoms are sensitive to pollution, acidification, turbidity, salinization, nutrient loading and thermal alterations. However diatom identification can be difficult since there are hundreds of thousands of species and many that have yet to be identified. Diatom taxonomy is in a state of flux, and varying protocols for diatom identification have created confusion in the use of diatoms for assessments. Specimens are often examined by light microscopy (LM) and scanning electron microscopy (SEM) to provide morphological identifications. Species can be difficult to distinguish because the morphology of a species can be influenced by the life cycle stage and phenotypic plasticity in response to environmental conditions. These factors affect estimates of biodiversity. More accessible and newer DNA-based methods have led to some revisions of the morphology-based taxonomy, including descriptions of new genera and species that are morphologically cryptic. These methods also have provided evidence to question the accuracy of diatom identification using morphology alone. Many researchers believe that DNA barcoding would be a valuable tool to provide a consistent categorization that can be used to enhance the identification of diatoms and make the data from different studies directly comparable, even if taxonomy changes. In this study, environmental sampling from Connecticut's Eightmile River would be performed followed by DNA barcoding. This protocol could provide information about the diversity of diatoms found in a river sample. If this method can be consistently applied and optimized, use of this procedure in conjunction with morphological examination may have a significant impact on the accurate identification of these important organisms as water quality biological indicators.