Development Under ElevatedpCO₂Conditions Does Not Affect Lipid Utilization and Protein Content in Early Life-History Stages of the Purple Sea Urchin,Strongylocentrotus purpuratus

Abstract

Ocean acidification (OA) is expected to have a major impact on marine species, particularly during early life-history stages. These effects appear to be species-specific and may include reduced survival, altered morphology, and depressed metabolism. However, less information is available regarding the bioenergetics of development under elevated CO(2) conditions. We examined the biochemical and morphological responses of Strongylocentrotus purpuratus during early development under ecologically relevant levels of pCO(2) (365, 1030, and 1450 μatm) that may occur during intense upwelling events. The principal findings of this study were (1) lipid utilization rates and protein content in S. purpuratus did not vary with pCO(2); (2) larval growth was reduced at elevated pCO(2) despite similar rates of energy utilization; and (3) relationships between egg phospholipid content and larval length were found under control but not high pCO(2) conditions. These results suggest that this species may either prioritize endogenous energy toward development and physiological function at the expense of growth, or that reduced larval length may be strictly due to higher costs of growth under OA conditions. This study highlights the need to further expand our knowledge of the physiological mechanisms involved in OA response in order to better understand how present populations may respond to global environmental change.

Experimental ocean acidification alters the allocation of metabolic energy

“…Protein growth was maintained by changing the balance between increased rates of protein synthesis and decreased protein depositional efficiency. Our findings support prior work showing that ocean acidification does not affect protein content (22) but highlight the critical need to study the mechanisms and dynamics of biosynthesis, which undergo dramatic changes to compensate for the maintenance of biochemical content during growth. Similarly, our results show that increases in ion transport by Na + ,K + -ATPase and the concomitant increase in ATP demand were not predicted by changes in the expression of the gene coding for that protein or by changes in the amount of total enzyme.…”

Response of Copepods to Elevated pCO2 and Environmental Copper as Co-Stressors – A Multigenerational Study

“…This contrasting growth response indicates that, in this particular situation, Tisbe are preferentially reallocating energy to somatic growth at the expense of fecundity. Stump et al 2011 [63] observed developmental delay in sea urchin larvae alongside increased metabolic rates, suggesting that changes in energy budgets may result from ocean acidification stress leading to increased scope for growth; however, no such pattern was observed by Matson et al 2012 [64]. An alternative explanation may be that under the culture conditions, the animals were copper deficient and by increasing copper bioavailability through pH manipulation we have thereby released Tisbe from a growth limiting condition.…”

The stunting effect of a high CO2ocean on calcification and development in sea urchin larvae, a synthesis from the tropics to the poles

“…The larvae of S. purpuratus from the Eastern Pacific upwelling system are comparatively more resilient to nearfuture acidification projections, exhibiting a low decrease in arm growth in high pCO 2 [31,32,56]. Populations of S. purpuratus from this region have experienced upwelling of CO 2 -rich water for thousands of years and so may be acclimatized/ adapted to seawater acidification [31,32,56].…”

“…Populations of S. purpuratus from this region have experienced upwelling of CO 2 -rich water for thousands of years and so may be acclimatized/ adapted to seawater acidification [31,32,56]. However, the shifting baseline of increasing acidification may move pH spikes during upwelling to levels beyond present day threshold tolerances, as indicated by failure of spat in bivalve hatcheries in the region [33].…”