Exposure to Elevated Temperature and Pco₂Reduces Respiration Rate and Energy Status in the PeriwinkleLittorina littorea

Abstract

In the future, marine organisms will face the challenge of coping with multiple environmental changes associated with increased levels of atmospheric Pco(2), such as ocean warming and acidification. To predict how organisms may or may not meet these challenges, an in-depth understanding of the physiological and biochemical mechanisms underpinning organismal responses to climate change is needed. Here, we investigate the effects of elevated Pco(2) and temperature on the whole-organism and cellular physiology of the periwinkle Littorina littorea. Metabolic rates (measured as respiration rates), adenylate energy nucleotide concentrations and indexes, and end-product metabolite concentrations were measured. Compared with values for control conditions, snails decreased their respiration rate by 31% in response to elevated Pco(2) and by 15% in response to a combination of increased Pco(2) and temperature. Decreased respiration rates were associated with metabolic reduction and an increase in end-product metabolites in acidified treatments, indicating an increased reliance on anaerobic metabolism. There was also an interactive effect of elevated Pco(2) and temperature on total adenylate nucleotides, which was apparently compensated for by the maintenance of adenylate energy charge via AMP deaminase activity. Our findings suggest that marine intertidal organisms are likely to exhibit complex physiological responses to future environmental drivers, with likely negative effects on growth, population dynamics, and, ultimately, ecosystem processes.

The metabolic response of pteropods to acidification reflects natural CO<sub>2</sub>-exposure in oxygen minimum zones

“…High CO 2 decreases the metabolic rate in the mussel Mytilus galloprovincialis , the snail Littorina littorea (Melatunan et al, 2011), the thecosome pteropod Limacina helicina antarctica (Seibel et al, 2012) and the Humbolt squid Dosidicus gigas (Rosa and Seibel, 2008). Other research found an increase in metabolic rate of the pteropod Limacina helicina (Comeau et al, 2009(Comeau et al, , 2010a and in the bivalve Laternula elliptica (Cummings et al, 2011), whereas there was no change in the metabolic rate of the cuttlefish Sepia officianlis (Gutowska et al, 2008) and the mussel Mytilus edulis (Thomsen and Melzner, 2010).…”

Adaptation and acclimatization to ocean acidification in marine ectotherms: anin situtransplant experiment with polychaetes at a shallow CO2vent system

“…However, the ability to cope with chronic exposure to elevated pCO 2 conditions appears to be characterized by the acquisition of moderately lower metabolic rates (on average 223% in this study) in both the acclimatized and the adapted species. While metabolic depression in the short term helps an organism to maintain a balance between energy supply and demand [15,16,25,26,111], in the longer term it can rstb.royalsocietypublishing.org Phil Trans R Soc B 368: 20120444 involve the reorganization of its energy budget, often leading to a decrease in its scope for growth and reproduction [2].…”

Physiological niche and geographical range in European diving beetles (Coleoptera: Dytiscidae)

“…For example, in Antarctic fish, it has been found that above their optimal temperature range, cellular processes switch from mainly carbohydrate (glucose and glycogen) to lipid and finally protein metabolism [6]. Other studies on marine gastropods into the effects of sub-lethal elevations in temperature reveal the accumulation of 'end-product' metabolites (lactate and succinate) while ATP concentrations remain stable, indicating an increased reliance on anaerobic metabolism with temperature, using carbohydrates as the energy source [7]. Plasticity of such metabolic processes may be vital in widespread, more northerly distributed species, as organisms encounter increasingly variable climates with latitude [8].…”