Ocean acidification induced by atmospheric CO2 may be a major threat to marine ecosystems, particularly to calcareous nannoplankton. We show that, during the Aptian (∼120 million years ago) Oceanic Anoxic Event 1a, which resulted from a massive addition of volcanic CO2, the morphological features of calcareous nannofossils traced the biological response to acidified surface waters. We observe the demise of heavily calcified nannoconids and reduced calcite paleofluxes at the beginning of a pre-anoxia calcification crisis. Ephemeral coccolith dwarfism and malformation represent species-specific adjustments to survive lower pH, whereas later, abundance peaks indicate intermittent alkalinity recovery. Deepwater acidification occurred with a delay of 25,000 to 30,000 years. After the dissolution climax, nannoplankton and carbonate recovery developed over ∼160,000 years under persisting global dysoxia-anoxia.
Calcareous nannoplankton response to surface-water acidification around oceanic anoxic event 1a / E. Erba, C. Bottini, H.J. Weissert, C.E. Keller. - In: SCIENCE. - ISSN 0036-8075. - 329:5990(2010), pp. 428-432. [10.1126/science.1188886]
Calcareous nannoplankton response to surface-water acidification around oceanic anoxic event 1a
E. Erba
;C. BottiniSecondo
;
2010
Abstract
Ocean acidification induced by atmospheric CO2 may be a major threat to marine ecosystems, particularly to calcareous nannoplankton. We show that, during the Aptian (∼120 million years ago) Oceanic Anoxic Event 1a, which resulted from a massive addition of volcanic CO2, the morphological features of calcareous nannofossils traced the biological response to acidified surface waters. We observe the demise of heavily calcified nannoconids and reduced calcite paleofluxes at the beginning of a pre-anoxia calcification crisis. Ephemeral coccolith dwarfism and malformation represent species-specific adjustments to survive lower pH, whereas later, abundance peaks indicate intermittent alkalinity recovery. Deepwater acidification occurred with a delay of 25,000 to 30,000 years. After the dissolution climax, nannoplankton and carbonate recovery developed over ∼160,000 years under persisting global dysoxia-anoxia.File | Dimensione | Formato | |
---|---|---|---|
Erba et al_2010.pdf
accesso riservato
Tipologia:
Publisher's version/PDF
Dimensione
738.33 kB
Formato
Adobe PDF
|
738.33 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.