N UECES B AY S ALINITY M ONITORING P ROJECT

1. NUECES BAY SALINITY MONITORING PROJECT Principle Investigator: John S. Adams, Division of Nearshore Research Conrad Blucher Institute for Surveying and Science, Texas A&M University-Corpus Christi History The health of the Nueces Estuary greatly depends on freshwater inflows into the Nueces Bay. The construction of Lake Salt 01 Nueces Bay Gulf of Mexico Corpus Christi in 1958 and the Choke Canyon Reservoir in 1987 reduced the amount of fresh water entering Nueces Bay by 99%, as determined by the Bureau of Reclamation. In 1992, an order was issued by the Texas Water Commission requiring water releases from the Lake Corpus Christi Reservoir, with a volume representative of that historically entering the bay. The order required continuous monitoring of salinity levels within the Nueces Bay system. Salt 03 Salt 04 Salinity: A major factor affecting the physical makeup of an estuary. Prolonged hypersaline conditions are harmful to the overall health and diversity of an estuary. pH: Acidic and alkaline waters adversely affect many biological processes. Acidic conditions cause sediments to release toxicants into the water. Dissolved Oxygen: Extended periods of depressed dissolved oxygen concentrations (<2mg/L) can lead to a “dead” estuary. Most desirable fish species suffer if concentrations fall below 3-4mg/L. Depth: Measured relative to station. Data Management • Data from the Salinity stations are collected at thirty minute intervals by the DNR network • Data acquisition, archiving and distribution take place autonomously • Daily data inspections result in timely station repairs and excellent data quality • The DNR system makes use of line-of-site radio and satellite IP technology to provide data to end-users in near-real time (less than five minute delay) • All DNR data are easily accessible through the DNR website Overview The Division of Nearshore Research began the Nueces Bay Salinity Monitoring Project in 1991, under the sponsorship of the City of Corpus Christi. Monitoring stations are deployed throughout the Nueces Bay, River and Delta to continuously measure salinity, along with temperature, pH and dissolved oxygen. Salt 05 DNR Data Query Page Salt 08 The above parameters are measured using a Hydrolab ™ H2O Multiparameter Water Quality Sensor Decreased salinity concentrations following heavy rains in the Nueces Estuary are graphed using DNRs Data Query page The DNR website displays Quality Control Graphs in near-real time http://lighthouse.tamucc.edu/Salinity Whites Point