Anthropogenic CO2 emissions are acidifying the world’s oceans. A growing body of evidence demonstrates that this ocean acidification can impact survival, growth, development and physiology in marine invertebrates. A few years ago, a global analysis of the literature revealed that echinoderms were surprisingly robust to ocean acidification (Dupont et al., 2010a). An updated semi-quantitative analysis of the literature confirms that sea urchins are resilient to near-future ocean acidification. Direct impacts of ocean acidification on sea urchins are mostly negative but sub-lethal. These include slower somatic and gonadal growth and reflect a shift in energy budgets linked to additional costs of pHe and pHi regulation rather than a direct impact on calcification. This highlights the plasticity of this taxonomic group at levels from molecular to whole organism physiology when facing a changing environment. All life-history stages can be impacted but juveniles are the most sensitive to near-future ocean acidification. Sea urchins also show evidence of acclimation and adaptation potential. However, despite some resilience to ocean acidification in adult and larval stages, strong negative carry-over effects between adult, larval and juvenile stages are likely to compromise the sustainability of some urchin populations. Most of the published evidence are based on short term analyses and focus on single life-history stages, neglecting key processes such as carry-over effects between different life-history stages and generations. As a consequence, the vast majority of published evidence probably underestimates the real impact of ocean acidification. Recommendations for experimental design and future research priorities are discussed.

Dupont S. & Thorndyke M., 2013. Direct impacts of near-future ocean acidification on sea urchins. In Fernández-Palacios J. M., de Nascimento L., Hernández J. C., Clemente S., González A. & Díaz-González J. P., Climate change perspective from the Atlantic: past, present and future. Servicio de Publicaciones, Universidad de La Laguna. pp. 461-485. Book chapter.