Plastic response of the oyster Ostrea chilensis to temperature and pCO2 within the present natural range of variability

Abstract

Estuaries are characterized by high fluctuation of their environmental conditions. Environmental parameters measured show that the seawater properties of the Quempillé n estuary (i.e. temperature, salinity, pCO 2 , pH and ΩCaCO 3) were highly fluctuating and related with season and tide. We test the effects of increasing temperature and pCO 2 in the seawater on the physiological energetics of the bivalve Ostrea chilensis. Juvenile oysters were exposed to an orthogonal combination of three temperatures (10, 15, and 20˚C) and two pCO 2 levels (~400 and~1000 μatm) for a period of 60 days to evaluate the temporal effect (i.e. 10, 20, 30, 60 days) on the physiological rates of the oysters. Results indicated a significant effect of temperature and time of exposure on the clearance rate, while pCO 2 and the interaction between pCO 2 and the other factors studied did not show significant effects. Significant effects of temperature and time of exposure were also observed on the absorption rate, but not the pCO 2 nor its interaction with other factors studied. Oxygen consumption was significantly affected by pCO 2 , temperature and time. Scope for growth was only significantly affected by time; despite this, the highest values were observed for individuals subject to to 20˚C and to~1000 μatm pCO 2. In this study, Ostrea chilensis showed high phenotypic plasticity to respond to the high levels of temperature and pCO 2 experienced in its habitat as no negative physiological effects were observed. Thus, the highly variable conditions of this organism's environment could select for individuals that are more resistant to future scenarios of climate change, mainly to warming and acidification.

Population-specific effects of ocean acidification in the Olympia oyster

“…Curiously, despite size differences associated with parental treatments in the Oyster Bay population, there were no differences in gene expression. Differing sizes may therefore not be due to variable growth rate, as that would likely have been reflected in expression profiles (Meyer & Manahan, 2010; Pace et al, 2006). It is possible that cryptic intergenerational transcriptome plasticity could be induced by high pCO 2 or other environmental stressors, but that was not revealed under ambient conditions in which larvae were reared.…”

“…Multiple studies have reported little to no effects of acidification in Ostrea spp. at the adult (Lemasson et al, 2018;Lemasson et al, 2019;Lemasson & Knights, 2021), juvenile (Navarro et al, 2020), and larval stages (Cole et al, 2016;Pereira et al, 2019;Waldbusser et al, 2016). In one study O. edulis larval growth and survival responded positively to acidification exposure (Prado et al, 2016).…”

Comparing life history traits and tolerance to changing environments of two oyster species (Ostrea edulis and Crassostrea gigas) through Dynamic Energy Budget theory

“…Warming seawater and air temperature in combination with decreasing alkalinity will increase the maintenance costs of intertidal populations. The impact of these factors and synergistic effects on the performance of the Ostrea and the Crassostrea genus have recently been a focus of study and concluded that larvae from brooding species were more tolerant to ocean acidification (in combination with other pressures) compared with broadcaster species ( Gazeau et al, 2013 ; Ko et al, 2014 ; Cole et al, 2016 ; Gray et al, 2019 ; Navarro et al ., 2020 ).…”

Juvenile Atlantic sea scallop, Placopecten magellanicus, energetic response to increased carbon dioxide and temperature changes

“…For the northern quahog, Mercenaria mercenaria, the combined effects of warming and increased CO 2 resulted in increased RR, but no effect was observed in the Eastern oyster, Crassostrea virginica [28]. Conversely, the oyster Ostrea chilensis showed no effects of high temperature and CO 2 upon physiological processes, indicating that this species may show high tolerance to these changes [29]. The above findings demonstrate that CO 2 and warming should be studied concomitantly as the interaction of these two factors may change the response of a species to future environmental conditions.…”