Biological impacts of deep-sea carbon dioxide injection inferred from indices of physiological performance

Abstract

SUMMARYA recent proposal to store anthropogenic carbon dioxide in the deep ocean is assessed here with regard to the impacts on deep-living fauna. The stability of the deep-sea has allowed the evolution of species ill-equipped to withstand rapid environmental changes. Low metabolic rates of most deep-sea species are correlated with low capacities for pH buffering and low concentrations of ion-transport proteins. Changes in seawater carbon dioxide partial pressure (PCO2) may thus lead to large cellular PCO2 and pH changes. Oxygen transport proteins of deep-sea animals are also highly sensitive to changes in pH. Acidosis leads to metabolic suppression, reduced protein synthesis,respiratory stress, reduced metabolic scope and, ultimately, death. Deep-sea CO2 injection as a means of controlling atmospheric CO2levels should be assessed with careful consideration of potential biological impacts. In order to properly evaluate the risks within a relevant timeframe,a much more aggressive approach to research is warranted.

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

“…Full compensation for these changes often takes up to 48-72 h (Seibel and Walsh, 2003). The response measured in our experiments, being after only 6-18 h of exposure, may not be one of a final stable steady state and cannot be interpreted as indicative of a response to chronic acidification, only to the type pteropods would experience during short migrations into regions of hypercapnia.…”

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].…”

The rate of metabolism in marine animals: environmental constraints, ecological demands and energetic opportunities

“…Oxygen consumption rates have now been measured for deep-and shallow-living representatives of many major phyla, both benthic and pelagic, and in several regions. Biochemical proxies of metabolism have provided estimates of metabolic capacity in many additional species (Torres & Somero 1988;Childress & Somero 1990;Seibel et al 1998Drazen 2002a;Seibel & Walsh 2003;Treberg et al 2003;Dalhoff 2004;Thuesen et al 2005b), while submersibles, landers and new tagging techniques have provided detailed studies of locomotion and behaviour in the deep sea (Priede et al 1990;Marshall & Diebel 1995;Villanueva et al 1997;Hunt & Seibel 2000;Bailey et al 2003Bailey et al , 2005Drazen & Robison 2004;Robison 2004;Seibel et al 2005). More than 10 years have passed since the last specific reviews of deep-sea metabolic rates (Childress 1995;Mahaut et al 1995).…”