The responses of subtropical nearshore fishes to climate change

• Main Author: Shultz, Aaron D.
• Other Authors: Suski, Cory, Philipp, David, Brawn, Jeffrey, Weatherhead, Patrick, Bell, Alison
• Format: Text
• Language: English
• Published: 2015
• Subjects: Blood chemistry; multiple stressors; nearshore; physiological response; stress; temperature; scope for activity; metabolic rate; performance; oxygen capacity limited thermal tolerance; carbon dioxide; salinity; acclimation; ocean acidification; respirometry; marine community; ectotherm; Critical Thermal Maximum (CTMax); Critical Thermal Minimum (CTMin); thermal scope; plasticity; climate change; extreme weather; physiological costs; behavior; predation; Ocean acidification
• Online Access: http://hdl.handle.net/2142/88975

Global climate change is expected to alter seawater conditions and marine ecosystems. The Intergovernmental Panel on Climate Change (IPCC) predicts that sea surface pH will decrease by 0.06 - 0.32 pH units and temperature will increase by 0.6-2.0°C over the next 100 years, and extreme weather events, such as major storms (e.g., tropical cyclones), floods, heat waves, and cold spells, are expected to increase in intensity and frequency. Nearshore ecosystems serve as critical habitat for juvenile fishes (e.g., schoolmaster snapper, yellowfin mojarra) and function as foraging grounds for adults (e.g., bonefish, checkered puffer), yet it is unclear how nearshore fishes will respond to forecasted increases in temperature and pCO2. To fill this knowledge gap, I assessed the physiology, behavior, and thermal plasticity of nearshore species challenged by climate change stressors, and determined how the presence of a predator will influence habitat choice under forecasted conditions. Climate change research on marine organisms has primarily focused on species that inhabit the open ocean or coral reef environments. Elevated temperature, salinity, and acidity (reduced pH) have all been shown to result in varying degrees of physiological disturbance in organisms across ecosystems, yet little effort has been devoted to understanding the magnitude of these disturbances in nearshore fishes across seasons. Moreover, few studies have investigated the synergistic (or canceling) effects of combined climate-related challenges. Based on this background, the purpose of this aspect of the study was to assess the relative impacts of climate-related challenges across seasons on fishes that inhabit the nearshore ecosystem. To do this, blood-based physiological responses to elevated temperature, salinity, acidity, and temperature + acidity of adult bonefish, adult checkered puffer, and juvenile yellowfin mojarra were compared across seasons (i.e., summer and winter). Bonefish exposed to climate-related challenges experienced elevated Cl-, ...