Temperature and acidification variability reduce physiological performance in the intertidal zone porcelain crab Petrolisthes cinctipes.
We show here that increased variability of temperature and pH synergistically negatively affects the energetics of intertidal zone crabs. Under future climate scenarios, coastal ecosystems are projected to have increased extremes of low tide-associated thermal stress and ocean acidification-associated low pH, the individual or interactive effects of which have yet to be determined. To characterize energetic consequences of exposure to increased variability of pH and temperature, we exposed porcelain crabs, Petrolisthes cinctipes, to conditions that simulated current and future intertidal zone thermal and pH environments. During the daily low tide, specimens were exposed to no, moderate or extreme heating, and during the daily high tide experienced no, moderate or extreme acidification. Respiration rate and cardiac thermal limits were assessed following 2.5 weeks of acclimation. Thermal variation had a larger overall effect than pH variation, though there was an interactive effect between the two environmental drivers. Under the most extreme temperature and pH combination, respiration rate decreased while heat tolerance increased, indicating a smaller overall aerobic energy budget (i.e. a reduced O2 consumption rate) of which a larger portion is devoted to basal maintenance (i.e. greater thermal tolerance indicating induction of the cellular stress response). These results suggest the potential for negative long-term ecological consequences for intertidal ectotherms exposed to increased extremes in pH and temperature due to reduced energy for behavior and reproduction.
Romberg Tiburon Center for Environmental Studies, San Francisco State University, 3150 Paradise Drive, Tiburon, CA 94920, USA.
Adam W
AW
Paganini
Romberg Tiburon Center for Environmental Studies, San Francisco State University, 3150 Paradise Drive, Tiburon, CA 94920, USA.
Nathan A
NA
Miller
Romberg Tiburon Center for Environmental Studies, San Francisco State University, 3150 Paradise Drive, Tiburon, CA 94920, USA Department of Integrative Biology, University of California Berkeley, 3040 Valley Life Sciences, Building no. 3140, Berkeley, CA 94720, USA Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132, USA stillmaj@sfsu.edu.
Jonathon H
JH
Stillman
D000064:Acclimatization; D000818:Animals; D033381:Anomura / Q000502:physiology*; D057231:Climate Change; D006358:Hot Temperature / Q000009:adverse effects*; D006863:Hydrogen-Ion Concentration; D012623:Seawater / Q000737:chemistry*; D013312:Stress, Physiological; D055871:Tidal Waves
Comparative physiology; Global warming; Marine; Metabolism; Ocean acidification; Thermal tolerance