Temperature and acidification variability reduce physiological performance in the intertidal zone porcelain crabPetrolisthes cinctipes

Abstract

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 O 2 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.

Urchins in a high CO2 world: partitioned effects of body-size, ocean warming and acidification on metabolic rate

“…This highlights the highly partitioned nature of these factors, and suggests that the mechanisms by which each influences metabolism are relatively separated within the physiological pathway. By contrast, other studies of marine invertebrates, albeit often with brief acclimation and narrow size ranges, suggest that the combined metabolic effects of temperature and pH are highly interactive Matoo et al, 2013;Melatunan et al, 2011;Paganini et al, 2014;Uthicke et al, 2014). The increased energetic costs that are associated with a R, metabolic rate (oxygen uptake, mg O 2 h −1 ); M, ash-free dry mass (see also Fig.…”

“…Warming and acidification are known to cause metabolic changes in marine invertebrates, and in combination frequently act interactively (e.g. Catarino et al, 2012;Paganini et al, 2014). Body size has been shown to affect the magnitude of response to both of these stressors (Appelhans et al, 2014;.…”

Thermal variation, thermal extremes and the physiological performance of individuals

“…However, true integration of the lessons of biochemical adaptation and ecomechanics to study physiological variation requires overcoming several lingering challenges and then developing rigorous, empirical means to test these ideas. Ultimately, individual performance is highly dependent on a multitude of physical factors (temperature being but one, Paganini et al, 2014) and on the specific ecological context (Pörtner et al, 2006;Rosa and Seibel, 2008). This complexity demands concerted efforts from biologists of all stripes to tackle the causes and consequences of variation.…”

Interactive effects of seawater acidification and elevated temperature on biomineralization and amino acid metabolism in the musselMytilus edulis

“…Global seawater surface pH is projected to drop a further 0.3-0.4 units by the end of this century, with seawater warming of 1-4°C (Bates et al, 2008;Doney et al, 2012). Seawater acidification and warming have negative impacts on the larval development, growth, reproduction, biomineralization, and physiological and biochemical performance of some marine organisms, especially marine calcifiers, by disturbing ion and acid-base equilibrium, energy budgets and calcium carbonate (CaCO 3 ) saturation state (CeballosOsuna et al, 2013;Gazeau et al, 2013;Paganini et al, 2014;Pimentel et al, 2014;Rosa et al, 2014;Schlegel et al, 2015;Stillman and Paganini, 2015;Turner et al, 2015;Wittmann and Portner, 2013;Yao and Somero, 2014).…”