Application of an ecological health assessment for Reclamation managed reservoirs
1) What kind of aquatic indicators can be monitored to determine the ecological condition of Reclamation reservoirs in the western US? 2) Can a standardized ecological health assessment be used to assess, rate, and compare ecological condition of reservoirs operated and managed by Reclamation? 3) Could an ecological reservoir health assessment be used to fulfill both water quality and fisheries type data needs? 4) Could an ecological reservoir health assessment be implemented to a centralized web-based database?
Need and Benefit
There have been many investigations using physiochemical (water temperature, dissolved oxygen, and water quality) or biological parameters (chlorophyll-a, macroinvertebrate, and fish) performed by different offices of Reclamation. Some have been conducted in short- and long-term periods and others periodically at established monitoring intervals. However, these data have been mostly used and stored separately when projects were completed. In addition, these parameters will vary depending on the natural conditions at the time of sampling, for example, fluctuation of precipitation, inflow, water level, and temperature with climate change. It could be difficult to understand and compare these parameters without temporal and spatial characteristics of the hydrologic and thermal regimes. Most investigations have described measured or mean values on physiochemical parameters and lists of fauna species with individual numbers and catch rate statistics in the results. Through the use of an Ecological Health Assessment these data (temporal and spatial) could be easily compared. However, it is very difficult to assess the general ecological condition of reservoirs with the comparison of individual parameters. Therefore, there would be value in developing a standardized list of parameters (subset) from a larger list of commonly sampled parameters that could be used in the development of an Ecological Health Assessment.
The overall reservoir rating on an Ecological Health Assessment is based on a number of indicators and is determined by taking the sum of each index from sites up to four locations, divided by the maximum possible rating for that reservoir, and expressed as a percentage. Application of the Ecological Health Assessment on reservoirs with a decision of indicators and its indexing would provide comparable rates by time and site as well as ecological health status trends. The findings could be used to indicate conditions that could cause environmental concerns if left unnoticed.
The development of a web-based database that could apply an Ecological Health Assessment for a reservoir could be a valuable tool for general characterization of the aquatic ecosystem and making comparisons between Reclamation reservoirs. Also, such a database could be used to describe baseline conditions for future reporting and coupled with literature reviews to design more specific studies when necessary. Furthermore, these data would be very important sources for long-term trends because individual parameters would be varied widely due to an ecological complexity. If made available on the web (intranet) the potential for use (and improvement) would be increased over time.
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Bureau of Reclamation Review
The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.
Assessing the Ecological Health of Reclamation's Reservoirs (final, PDF,
By Dmitri Vidergar
Publication completed on September 30, 2014