Ocean Acidification in Larval Sea Urchins from Low pH Environments
Evans, T.G. and G.E. Hofmann (2012) Defining the limits of physiological plasticity: how gene expression can assess and predict the consequences of ocean change. Phil. Trans. of Royal Soociety B 367, 1733-1745 doi: 10.1098/rstb.2012.0019
Kelly, M. W. and G.E. Hofmann (2012) Adaptation and the physiology of ocean acidification.Functional Ecology. doi:10.1111/j.1365-2435.2012.02061.x
Evans,T.G., F.Chan,B.A. Menge and G.E. Hofmann (2013) Transciptomic responses to ocean acidification in larval sea urchins from a naturally low pH environment. Molecular Ecollgy.doi:10.1111/mec.12188
Yu,P.C., P.G. Matson, T.R. Martz and G.E. Hofmann (2011) The ocean acidification seascape and its relationship to the performance of calcifying marine invertebrates: laboratory experiments on the development of urchin larvae framed by environmetally relevant pCO2/pH. Journal of Experimental Marine Biology and Ecology 400: 288-295
Hofmann, G.E., M.J. O’Donnell and A.E. Todgham (2008) Using functional genomics to asess the impact of ocean acidification on calcifying marine organisms. Mar Ecol. Prog. Series.373:219-225
Malakoff, D. (2012) Researcher struggle to assess responses to ocean acidification. Science 338 (5): 27-28.
Very briefly tell us a bit about yourself, your career path over the years, and specifically what brought you to begin researching ocean acidification?
L. David Smith
Do you think the adaptive changes that you observe in your test organisms will be sufficient to maintain an ocean ecosystem in 100 years if CO2 levels continue to increase at their current rate? You mention coral bleaching and a decrease in photosynthesis levels in plants–isn’t there a point where small adaptive changes can’t keep up, because the exosystem is collapsing? Will we reach that point?
Given that deeper waters have even more dissolved CO2 than shallow waters, do ‘deeper’ organisms have better (or any) internal mechanisms for dealing with low-acid environments? Do you anticipate that organisms in deep ocean waters could handle further acidification better than shallow organisms?
In your 2012 paper, “Adaptation and the physiology of ocean acidification,” you mention a study that found that the coccolithophore E. hyxleyi showed substantial adaptive evolution in its calcification response under high CO2 conditions in a laboratory. However, in the ocean, coccolithophores would face competition with other phytoplankton species that do not rely on calcification, such as diatoms; how would the effects of such competition affect their potential for adaptation?
In your research on transcptomics of acidification in urchins you find that early life stage embryos “can mount an adaptive response to elevated pCO2.” Do you think this adaptive response could be naturally selected for in future generations of urchins or will drastic shifts in pH surpass the ability for these urchins to adapt?
You demonstrated that in different species of musels occupying different temperature niches, that the heat shock response system was different between species. Because the heat stress response, especially in terms of HSPs, is so heavily conserved across species, as the earth experiences global climate change that causes temperature extremes, do you think the system as a whole is plastic and adaptable to these changes? Could one species’ HS response be more sensitive than another?
Do symbionts also possess the ability to display phenotypic plasticity as a response to increased pCO2 levels? IN addition, is it possible to perhaps use CSR symbionts to have a better understanding of the host-symbiont relationship?
Have transcriptomic studies revealed any genes that confer resilience to environmental changes? If yes, are there any that are conserved across taxa?
In the 2013 article, you mentioned major developmental pathways such as the noncanonical Wnt pathway, Notch signaling, FGF signaling, etc. that could potentially be affected by increased levels of pCO2. How does pCO2 interact with these pathways, which may ultimately affect downstream effector genes involved in calcification?
Is the process of calcification in urchins less metabolically expensive than that found in orals? Is it likely that the variation between the calcification processes in urchins and corals will lead to differential tolerance to ocean acidification?