Studies done in Texas estuaries in the Gulf of Mexico to determine the roles of freshwater inflows found altering the hydrology could cause changes in estuarine systems (Palmer et al. 2011). The inflow studies done to assess the effects of changing flows used benthic invertebrates and macrofauna biomass as bioindicators (Palmer et al. 2008). Bioindicators are species that can be used to signify the health of an ecosystem. Benthic biomass varies by condition. The condition can be defined as the state of ecological resources and the interconnections of ecological resources. Salinity was deemed as the most important ecological condition determining bioindicator species biomass, abundance, and biodiversity. Therefore, these measured changes in bioindicator are correlated with changing freshwater inflows (Kim et al. 2009). Estuarine systems experience changes in many ecosystem components due to altered freshwater inflows including hydro climate, water quality, benthic communities, epibenthic communities, fish communities, invasive species, ecosystem services, and other water resources. Estuarine ecosystem changes have resulted in losses of habitat, biodiversity, and productivity (Montagna et al. 2002b). The use of bioindicators to determine a salinity tolerance range of that bioindicator and then link the salinity range to quantities of freshwater inflows has been integrated and modeled by the Domino Theory as discussed previously and here more in-depth.