Ecosystem resilience following salinity change in a hypersaline estuary. (30th September 2019)

• Record Type: Journal Article
• Authors: Breaux, Natasha; Lebreton, Benoit; Palmer, Terence A.; Guillou, Gaël; Beseres Pollack, Jennifer
• Is Part Of: Estuarine, coastal and shelf science. Volume 225(2019)
• Publication Date: 2019-09-30
• Subjects: Carbon isotope ratio -- Black drum -- Pogonias cromis -- Benthos -- Trophic relationships -- USA -- Texas -- Baffin bay estuary; Estuarine oceanography -- Periodicals; Coasts -- Periodicals; Estuarine biology -- Periodicals; Seashore biology -- Periodicals; Coasts; Estuarine biology; Estuarine oceanography; Seashore biology; Periodicals; 551.461805
• DOI: 10.1016/j.ecss.2019.106258
• Languages: English
• ISSNs: 0272-7714

Abstract

Abstract: Salinity variability can act as a disturbance to communities in estuarine systems. Climate models predict changes in precipitation patterns will increase future hydrological variability, particularly in the southwestern United States. This study used infaunal community characterization, stomach content, and stable isotope analyses to evaluate the functioning of an estuarine food web over a range of wet and dry conditions. Baffin Bay is a predominantly hypersaline system in the semi-arid region of South Texas, USA supporting large populations of Pogonias cromis, black drum, a commercially important benthic predator. Salinity was the best predictor of changes in benthic macrofauna biomass, abundance, and diversity in Baffin Bay. Isotopic analyses of muscle tissues indicate that black drum use resources, particularly deposit-feeding benthic macrofauna, from both Baffin Bay and an adjacent system under normal estuarine salinity (≤35) conditions, but are more constrained to Baffin Bay under hypersaline (>35) conditions. This spatial restriction may be due to the energetic cost of osmotic regulation in hypersaline conditions, which can limit movement of euryhaline fish. Understanding the impacts of salinity change on benthic prey availability and trophic interaction dynamics is critical to determining ecosystem-scale effects of salinity variability. Graphical abstract: Image 1 Highlights: High salinity leads to low benthic prey availability in the Baffin Bay complex. Deposit feeders compose the majority of Baffin Bay complex benthic predator diet. Lower salinity conditions favor fish migration for feeding purposes.