Physiological advantages of dwarfing in surviving extinctions in high-CO2 oceans

Abstract

Physiological changes associated with dwarfing in two marine molluscs that are adapted to acidified seawater at shallow CO2 seeps help the animals keep their shells intact. Such changes may have helped species to survive past mass extinction events. Excessive CO2 in the present-day ocean–atmosphere system is causing ocean acidification, and is likely to cause a severe biodiversity decline in the future1, mirroring effects in many past mass extinctions2,3,4. Fossil records demonstrate that organisms surviving such events were often smaller than those before5,6, a phenomenon called the Lilliput effect7. Here, we show that two gastropod species adapted to acidified seawater at shallow-water CO2 seeps were smaller than those found in normal pH conditions and had higher mass-specific energy consumption but significantly lower whole-animal metabolic energy demand. These physiological changes allowed the animals to maintain calcification and to partially repair shell dissolution. These observations of the long-term chronic effects of increased CO2 levels forewarn of changes we can expect in marine ecosystems as CO2 emissions continue to rise unchecked, and support the hypothesis that ocean acidification contributed to past extinction events. The ability to adapt through dwarfing can confer physiological advantages as the rate of CO2 emissions continues to increase.

Cite this article

Garilli, V., Rodolfo-Metalpa, R., Scuderi, D. et al. Physiological advantages of dwarfing in surviving extinctions in high-CO₂ oceans. Nature Clim Change 5, 678–682 (2015). https://doi.org/10.1038/nclimate2616

View full text

>> Full Text:   Physiological advantages of dwarfing in surviving extinctions in high-CO2 oceans