Background: Approach of FIT using EBM

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Background: Approach of FIT using EBM

This section provides background information on  the basis for Freshwater Inflow Tools including defining decision-support tools, ecosystem-based management strategies, and the us of the Domino Theory model.



Ecosystem-based management (EBM) strategies require a comprehensive approach to incorporate land, energy, and natural resource use and allocation, involving species management, natural commodities, and humans as components (Arkema et al. 2006). EBM also incorporates data analysis of various interactions over different amounts of time and space (Hutchison 2011). This may be directed at the maintenance or enhancement of the entire riverine ecosystem, including its various aquatic and riparian biota and components from source to sea (Tharme, R.E. 2003). Implementing ecosystem management strategies necessitates knowledge of multiple disciplines and large data sets. Incorporation of the data and strategies often requires tools that use the best-available science (Curtice et al. 2012). Tools that incorporate operational processes and systems of an organization, such as EBM strategies are called decision-support tools.

A decision support tool (DST) traditionally assimilates operations processing systems while functioning at the highest level of information systems to aid decision makers in the decision making process and support the transference of knowledge to all levels of the system (Sprague and Watson 1986). The objective of a DST is to improve the functionality of people in an organization. A review of structural components of decision support tools can provide valuable information for applying the knowledge gained towards the creation of a web-based decision support tools used to inform managers of issues regarding freshwater inflows in estuarine systems.

Decision support systems are created through the use of frameworks that developers practice to organize their actions (Sprague and Watson 1986). By giving DSS parameters, one may understand the key components needed to create a DSS system. Fundamental components a DSS must have include dialog, data, and modeling (Alter 1980; Bennett 1977). A successful DSS equalizes the three components so it is easy to use by having informative text, makes available a wide variety of data, and provides analysis and modeling (Alter 1980; Bennett 1977). DSS are developed with the ability to be adaptable. DSS require human, hardware, software, and data source interaction (Sprague and Watson 1986). DSS are decision motivated because they are geared towards managers and policy makers. DSS occur at three levels of technology including specific DSS, DSS tools, and DSS generators (Alter 1980; Bennett 1977; Sprague and Watson 1986).

The creation of web-based decision support tools are a relatively recent occurrence that allows for the integration of large amounts od data. While all tools are meant for ecosystem management and generally feature concepts and terms within the scope of science, the approaches often vary greatly. For example, the EBM Network features hundreds of Geographic Information System (GIS) tools related to coastal-marine spatial planning and management decision-making ( The National Oceanic and Atmospheric Administration (NOAA) have created a Coastal Services Center web site that features GIS analysis tools such as habitat priority planning, manipulative tools such as lidar data handler, and data visualization tools such as historical hurricane tracks ( Also, the Texas Commission on Environmental Quality has an informative regulatory tool for environmental flows. It features papers regarding the environmental flows in Texas ( The specific tool will depend not only on the needs of the community but also the stage of the decision process (Klinsky et al. 2010). Below in the first table are some examples of currently available ecosystem-based tools networks.

Ecosystem-based tools networks.

Network Organization
Coastal Services Center National Oceanic and Atmospheric Administration
EBM Tools Network 4,000+ Member Network
Gulf of Mexico Alliance Partnership of states: Alabama, Mississippi, Texas, Florida, Louisiana
Texas Commission on Environmental Equality Texas Commission on Environmental Quality

Currently, there is a lack of web-based decision support tools for managing freshwater inflows into estuaries. A few web pages shown below in table 2 offer some information addressing freshwater inflow issues. In Texas, for example, only 5 decision support tools relating to freshwater inflows were found through a literature review and are shown below in Table 2. There is a need for new decision support tools to provide information on environmental flows to mangers.

Freshwater inflows information available online. The table shows A) Freshwater inflow information resources and B) the associated acronyms.

A. Resources Organization Overview
TX Environmental Flow Program (SB3) TCEQ Provides links to all existing reports regarding freshwater inflows
Senate Bill 3 Nueces BBASC BBASC Explains SB3 process and provides specific Nueces applications (BBEST and BBASC reports)
NERR Science Collaborative MANERR Project to address climate change by helping to establish freshwater inflow requirements
Freshwater Inflows and Estuaries TPWD Case studies of methodologies to estimate changes, impacts, and needs of freshwater inflows
Environmental Flows Information System for Texas CRWR Data models and database to determine environmental flow needs


 B. Acronym Organization
TCEQ Texas Commission on Environmental Quality
BBASC Basin and Bay Area Stakeholder Committee
MANERR Mission-Aransas National Estuarine Research Reserve
TPWD Texas Parks and Wildlife
CRWR Center for Research in Water Resources

       Levels of Decision Support Systems

The term decision support system (DSS) is given to three levels of hardware/software that vary in capabilities and therefore their relative purposes and tasks (Sprague and Watson 1986). Each DSS supplies managers with an education that they can use to understand and solve intricate problems. Freshwater Inflow Tools is a decision support tool falling under the DSS tool category.



The first of the three technologies is the specific DSS. This is the system that allows managers to carry out a task relating to a set of interconnected problems by doing the necessary work (Sprague and Watson 1986). An example of a specific DSS is a data collection program. The USGS uses data collection programs to download data from USGS gauges.  The data can then be manipulated temporally and spatially to query stream flows. The specific DSS actually does the job required.

The second of the three DSS technologies is the DSS Generator. The DSS generator has the ability to build a specific DSS using a platform of hardware and software (Sprague and Watson 1986). An example of a DSS Generator is the Executive Information Center (EIS) developed by Boeing Computer Services that has an array of integrated capabilities including report preparation, a modeling language, and statistical analysis, each available as a separate, specific DSS (Boeing). Each capability is offered separately but all work together using a common set of data to make financial decisions (Sprague and Watson 1986). The DSS Generator can create specific DSS by building upon the framework in place. DSS Generators can act as a stable environment from which specific DSS can be produced and modified easily (Sprague and Watson 1986).  The DSS Generator can also lead to the creation of DSS tools.

The third and final part of the DSS technologies is DSS tools. According to Sprague and Watson (1986), DSS tools are, “the most fundamental level of technology applied to the development of a DSS.” This is because a DSS Tool aids in the creation of a DSS Generator and/or a specific DSS. DSS Tools available have increased significantly in recent years. DSS Tools improve the overall functioning of a system. DSS Tools allow managers to make decisions concerning complex and dynamic systems. An example is the CommunityViz Tool developed by Placeways and used to make land-use related decisions by modeling and analyzing land use realities and possibilities (Sprague and Watson 1986). The development of DSS Tools requires the cooperation of human, software, and hardware systems alike.

        Approach of Freshwater Inflow Tools: Creating DST using EBM



Freshwater Inflow Decision support tool is an informative tool aimed at aided in the creation of ecosystem-based management strategies for freshwater inflows that integrates historic and current information, uses the cooperation of multiple agencies, provides studies used to determine freshwater requirements in estuaries of the Gulf of Mexico, considers policy and public outreach, and a plan of how to implement the strategy.

The purpose of this project was to integrate data previously collected along the Texas Coast in the Gulf of Mexico and use the information to create a web-based decision support tool for the management of freshwater inflow in estuaries. The sources of previously collected data are listed in the table below.

Existing long-term observation data networks for the Texas coast. A) Agencies and observing networks, and B) data available. Source: Dr. Paul Montagna

A. Identity Source
HRI Harte Research Institute, Texas A&M University-Corpus Christi (TAMUCC)
NASA National Aeronautics and Space Administration
NOAA National Oceanic and Atmospheric Administration
TCOON Texas Coastal Ocean Observing Network, TAMUCC
TCEQ Texas Commission on Environmental Quality
TGLO Texas General Land Office
TNRIS Texas Natural Resource Inventory
TPWD Texas Parks and Wildlife Department
TWDB Texas Water Development Board
USEPA U.S. Environmental Protection Agency
USGS U.S. Geological Survey


B. Category Data Sources
Hydrology Rain, runoff, gauged,  returns, evaporation, diversions TWDB, USGS
Water Quality Salinity, temperature, dissolved oxygen, nutrients, chlorophyll HRI, TCEQ, TPWD, USEPA
Habitats Area, geo-referenced locations TGLO, NOAA, USGS
Watersheds Locations, water quality TCEQ, USEPA
Remote Sensing Satellite imagery NASA, NOAA
Biological Fish, epifauna, infauna, juveniles, oysters HRI, TPWD
Socioeconomic Population, land use, economic HRI, NOAA, TNRIS

        Introduction to the Domino Theory

Studies conducted in Texas estuaries over the past twenty years have led to a culminating approach to studying freshwater inflows and creating flow standards. This is an introductory overview of the approach used to identify freshwater inflow needs in several Texas estuary studies and will be covered in greater detail later on. This decision-support tool will use the Domino Theory (Palmer et al. 2011, Montagna et al. 2011) that asserts that freshwater inflows indirectly affect estuarine resources. This is illustrated below:



The “Domino Theory” suggests freshwater inflows have an indirect effect. Source: Palmer et al. (2011) Hydrobiologia, 667:49-67.

The approach of the Domino Theory first identifies indicator species of interest. It then links estuarine species of interest to estuarine conditions, and then that estuarine condition to the corresponding range of freshwater inflows. Highlighted case studies conducted on Texas’ Coast  have used the Domino Theory technique.

The first step of the Domino Theory is to identify the bioindicator for a particular estuary. Bioindicators are species that can be used to signify the health of an ecosystem. The inflow studies done to assess the effects of changing flows in Texas estuaries used benthic invertebrates and macrofauna biomass as bioindicators (Palmer et al. 2008). The implications of using benthos are that freshwater inflows enhance secondary production because of the salinity gradients caused by mixing fresh water and sea water (Montagna and Kalke 1992).


Macrobenthos Source:

Benthic biomass, abundance, and diversity vary by estuarine condition. The condition can be defined as the state of ecological integrity and the functionality of connections between them (EPA 2008). Therefore, the changes in biomass are correlated with changing freshwater inflows (Kim et al. 2009). These studies done to determine the roles of freshwater inflows found altering the hydrology causes changes in estuarine systems (Palmer et al. 2011).

The use of benthic organisms is useful for several reasons. Benthos are used as indicators of many environmental stressors because they are able to integrate spatial and temporal changes in ecosystem factors (Smith et al. 2001). Another rationale for using benthos is that they cannot travel large distances when ecosystem conditions change. This is important because abundance, diversity, and biomass changes can be measured over long periods of time at established sampling points and more accurately reflect the changes in ecosystem condition. Other marine organisms such as fish are more mobile and changes in biomass, diversity, and abundance can be the result of other biological responses including avoidance.

Salinity Ranges Source:

Salinity Ranges Source:

The next step is to determine the salinity ranges or requirements of the bioindicator and to identify them spatially and temporarily (Montagna et al. 2002a, b, 2009). Salinity is the main factor for associated biological responses in the case studies that will be presented. Salinity ranges are useful because it is possible to measure the amount of freshwater inflows that are associated with those salinity levels in a particular estuary.

The third step is to identify the flow regime associated with the range of salinities, which s can be accomplished using hydrodynamics and salinity transport models (Montagna et al. 2002a, b, 2009). The freshwater inflow regime can be created taking into consideration the quantity and quality of freshwater, and tidal connections of the estuary.

The Domino Theory Approach is covered in further detail under The Domino Theory section.

        Case Studies

The case studies presented will include those done by the Basin and Bays Expert Science Teams (BEST) in estuaries along the Texas Coast in the Gulf of Mexico. The estuaries along Texas’s coast and in the Gulf of Mexico have been the source of many freshwater inflow studies in recent years. The estuaries studied include Sabine-Nueces Estuary, Trinity-San-Jacinto Estuary, Lavaca-Colorado Estuary, Guadalupe Estuary, Mission-Aransas Estuary, Nueces Estuary, and Laguna Madre Estuary. Texas’ coast is an ideal study area because of the somewhat similar geomorphic features of the estuaries and the climatic gradient of decreasing rainfall that runs along Texas’ coast from the northeast to the southwest end.

Much of the information used to create the content of Inflows, namely the case studies section, was taken from research conducted by the Basin and Bays Expert Science Teams (BBEST) in estuaries along the Texas Coast (TCEQ 2009).  These BBEST studies were performed to support the Senate Bill 3 environmental flow process in Texas.  These estuaries include the Sabine-Neches Estuary, Trinity-San Jacinto Estuary, Lavaca-Colorado Estuary, Guadalupe Estuary, Mission-Aransas Estuary, Nueces Estuary, and Laguna Madre Estuary and are shown in Figure 2.

Ongoing monitoring programs that focus on the needs and effects of freshwater inflows on Texas’ bays and estuaries provide sources of data. Monitoring programs are performed by multiple agencies including: Texas Water Developmental Board, Texas Parks and Wildlife Department, the Texas Commission on Environmental Quality, Basin and Bay Expert Science Teams, University of Texas at Austin Mission-Aransas National Estuarine Research Reserve,Center for Research in Water Resources, and the Environmental Protection Agency.

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