Integrated real-time monitoring system to investigate the hypoxia in a shallow wind-driven bay

Corpus Christi Bay (Texas, USA) is a shallow wind-driven bay which experiences hypoxia (dissolved oxygen < 2 mg/L) during the summer. Since this bay is a very dynamic system, the processes that control the hypoxia can last on the order of hours to days. Monitoring systems installed on a single type of platform cannot fully capture these processes at the spatial and temporal scales of interest. Therefore, we have integrated monitoring systems installed on three different platform types: (1) fixed robotic, (2) mobile, and (3) remote. On the fixed robotic platform, an automated profiler system vertically moves a suite of water quality measuring sensors within the water column for continuous measurements. An integrated data acquisition, communication and control system has been configured on our mobile platform (research vessel) for synchronized measurements of hydrodynamic and water quality parameters at greater spatial resolution. In addition, a high-frequency radar system has been installed on remote platforms to generate surface current maps for the bay. With our integrated system, we were able to capture evidence of a hypoxic event in summer 2007; moreover, we detected low dissolved oxygen conditions in a part of the bay with no previously reported history of hypoxia.

[1]  W. Schroeder,et al.  The role of stratification in the deoxygenation of Mobile Bay and adjacent shelf bottom waters , 1987 .

[2]  Sea surface conditions remotely sensed by upward-looking ADCPs , 1995 .

[3]  P. Montagna,et al.  The effect of freshwater inflow on meiofaunal and macrofaunal populations in the Guadalupe and Nueces Estuaries, Texas , 1992 .

[4]  S. Glenn,et al.  Long-term Real-time Coastal Ocean Observation Networks , 2000 .

[5]  Quay Dortch,et al.  Nutrient changes in the Mississippi River and system responses on the adjacent continental shelf , 1996 .

[6]  B. Hodges,et al.  Case Study: A Thin-Layer Gravity Current with Implications for Desalination Brine Disposal , 2011 .

[7]  M. Islam.  Development of a Coastal Margin Observation and Assessment System (CMOAS) to capture the episodic events in a shallow bay , 2010 .

[8]  Jerrold E. Marsden,et al.  Richardson number criterion for the nonlinear stability of three-dimensional stratified flow , 1984 .

[9]  S. Nixon,et al.  Stratification and bottom-water hypoxia in the Pamlico River estuary , 1992 .

[10]  Kyeong Park,et al.  Temporal variability in summertime bottom hypoxia in shallow areas of Mobile Bay, Alabama , 2007 .

[11]  R. Flint.  Long-term estuarine variability and associated biological response , 1985 .

[12]  P. Montagna,et al.  Short-term succession dynamics of macrobenthos in a salinity-stressed estuary , 2005 .

[13]  G. Ward.  Processes and trends of circulation within the Corpus Christi Bay National Estuary Program study area , 1997 .

[14]  J. Bonner,et al.  A mechanistic dissolved oxygen model of Corpus Christi Bay to understand critical processes causing hypoxia , 2008, OCEANS 2008.

[15]  David J. Hill,et al.  Anomaly detection in streaming environmental sensor data: A data-driven modeling approach , 2010, Environ. Model. Softw..

[16]  Y. C. Agrawal,et al.  Instruments for particle size and settling velocity observations in sediment transport , 2000 .

[17]  John W. Miles,et al.  On the stability of heterogeneous shear flows , 1961, Journal of Fluid Mechanics.

[18]  Katja Fennel,et al.  Measurements of spectral optical properties and their relation to biogeochemical variables and processes in Crater Lake, Crater Lake National Park, OR , 2006, Hydrobiologia.

[19]  James S. Bonner,et al.  Simulation of constituent transport using a reduced 3D constituent transport model (CTM) driven by HF Radar: Model application and error analysis , 2007, Environ. Model. Softw..

[20]  D. A. Trujillo,et al.  Accuracy of surface current velocity measurements obtained from HF radar in Corpus Christi Bay, Texas , 2004, IGARSS 2004. 2004 IEEE International Geoscience and Remote Sensing Symposium.

[21]  Louis N. Howard,et al.  Note on a paper of John W. Miles , 1961, Journal of Fluid Mechanics.

[22]  J. Barth,et al.  Instruments and methods Spectral light absorption and attenuation measurements from a towed undulating vehicle , 2000 .

[23]  Donald E. Barrick,et al.  Ocean Surface Currents Mapped by Radar , 1977, Science.

[24]  P. Montagna,et al.  Seasonal hypoxia and models of benthic response in a Texas Bay , 1999 .

[25]  Mark A. Moline,et al.  Sub-kilometer length scales in coastal waters , 2008 .

[26]  H. Paerl,et al.  Estimating the spatial extent of bottom-water hypoxia and habitat degradation in a shallow estuary , 2002 .