Determining the effects of freshwater inflow on benthic macrofauna in the Caloosahatchee Estuary, Florida

• Published in: Integrated environmental assessment and management Vol. 12; no. 3; pp. 529 - 539
• Main Authors: Palmer, Terence A, Montagna, Paul A, Chamberlain, Robert H, Doering, Peter H, Wan, Yongshan, Haunert, Kathleen M, Crean, Daniel J
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.07.2016
• Subjects: Animals; Aquatic ecosystems; Aquatic Organisms - physiology; Bioindicator; Brackish; Community structure; Ecohydrology; Ecosystem integrity; Environmental flow; Environmental Monitoring; Estuaries; Florida; Fresh water; Fresh Water - analysis; Freshwater environments; Indicator species; Infauna; Invertebrates - physiology; Legislation; Macrofauna; Marine; Salinity; State laws; Water flow; Water inflow; Water quality; Florida; United States > US; Ecohydrology; Bioindicator; Environmental flow; Infauna; Salinity
• ISSN: 1551-3777; 1551-3793
• DOI: 10.1002/ieam.1688

ABSTRACT Florida legislation requires determining and implementing an appropriate range and frequency of freshwater inflows that will sustain a fully functional estuary. Changes in inflow dynamics to the Caloosahatchee Estuary, Florida have altered salinity regimes that, in turn, have altered the ecological integrity of the estuary. The purpose of this current project is to determine how changes in freshwater inflows affect water quality, and in turn, benthic macrofauna, spatially within the Caloosahatchee Estuary and between multiyear wet and dry periods. Thirty‐four benthic species were identified as being indicator species for salinity zones, and the estuary was divided into 4 zones based on differences in community structure within the estuary. Community structure had the highest correlations with water quality parameters that were common indicators of freshwater conditions resulting from inflows. A significant relationship between salinity and diversity occurs both spatially and temporally because of increased numbers of marine species as salinities increase. A salinity‐based model was used to estimate inflow during wet and dry periods for each of the macrofauna community zones. The approach used here (identifying bioindicators and community zones with corresponding inflow ranges) is generic and will be useful for developing targets for managing inflow in estuaries worldwide. Integr Environ Assess Manag 2016;12:529–539. © 2015 SETAC Key Points A generic approach is developed to identify bioindicators of salinity zones with corresponding inflow ranges. The Caloosahatchee Estuary is divided into 4 macrobenthic community zones. Macrofauna communities are correlated with freshwater indicators, that is, salinity. Dry periods and high salinities correlate with increases in macrobenthic diversity.