Water Resources Research Act Program

Details for Project ID 2006PR29B

DISSOLVED OXYGEN DYNAMICS IN TWO RESERVOIRS OF CONTRASTING TROPHIC STATUS IN PUERTO RICO

Institute: Puerto Rico
Year Established: 2006 Start Date: 2006-03-01 End Date: 2008-08-30
Total Federal Funds: $40,000 Total Non-Federal Funds: $82,144

Principal Investigators: David Sotomayor, Martinez Gustavo, Luis Perez-Alegria, Carlos Santos

Abstract: The Puerto Rico 2002 Water Quality Inventory and List of Impaired Waters Report stated that all (18) reservoirs in Puerto Rico were impaired for aquatic life use, with the cause being low dissolved oxygen (DO) (PREQB, 2002). The eutrophic conditions due to inputs of sediments and nutrients to the reservoirs were identified as the primary reason for the lakes not meeting the water quality standard for DO. Changes in the trophic status of reservoirs may affect their DO concentrations and dynamics. Adequate assessment of the ecological conditions influencing DO concentratins in tropical reservoirs must include evaluation of temporal and spatial changes (including depth) in DO concentrations as well as associated nutrient concentration and ancillary parameters. A proper understanding of the DO dynamics in reservoirs cannot be drawn from historical water quality data gathered in reservoirs by public agencies in Puerto Rico, for example USGS monitoring network or PREQB. This study aims to characterize the DO dynamics in two reservoirs to calculate the areal O2 deficit (as an index of lake productivity). The data and indices generated will serve as baseline data for modeling purposes and for the eventual establishment of DO numeric criteria in Puerto Rico.