On the potential for ocean acidification to be a general cause of ancient reef crises

Abstract

Anthropogenic rise in the carbon dioxide concentration in the atmosphere leads to global warming and acidification of the oceans. Ocean acidification (OA) is harmful to many organisms but especially to those that build massive skeletons of calcium carbonate, such as reef corals. Here, we test the recent suggestion that OA leads not only to declining calcification of reef corals and reduced growth rates of reefs but may also have been a trigger of ancient reef crises and mass extinctions in the sea. We analyse the fossil record of biogenic reefs and marine organisms to (1) assess the timing and intensity of ancient reef crises, (2) check which reef crises were concurrent with inferred pulses of carbon dioxide concentrations and (3) evaluate the correlation between reef crises and mass extinctions and their selectivity in terms of inferred physiological buffering. We conclude that four of five global metazoan reef crises in the last 500 Myr were probably at least partially governed by OA and rapid global warming. However, only two of the big five mass extinctions show geological evidence of OA.

Effects of diurnally oscillatingpCO2on the calcification and survival of coral recruits

“…In the present study, coral recruits in diurnally oscillating pCO 2 on a natural phase were exposed to elevated DIC mostly in the form of HCO À 3 at night (table 1), which is thought to be used as the primary DIC source for calcification and photosynthesis in corals during the day [10,41,44 -45]. During night, HCO 3 2 might then be sequestered in the coral tissue.…”

“…Ocean acidification (OA) arising from the dissolution of atmospheric CO 2 in seawater is thought to be one of the most serious threats facing marine ecosystems [1][2][3], because most calcifying organisms deposit less CaCO 3 at high pCO 2 [4][5][6]. Some of the most striking examples of these effects are exhibited by scleractinian corals [7], yet despite the negative implications of these trends for coral reef ecosystems [8], progress has been slow in elucidating the mechanisms underlying the response of corals to high pCO 2 [9][10][11].…”

Long-term legacy of massive carbon input to the Earth system: Anthropocene versus Eocene

“…It is not clear, however, whether the benthic extinction was caused by changes in oxygenation, bottom water temperatures, carbonate undersaturation as a result of the carbon input, and/or other factors [25,65]. Finally, a growing body of evidence suggests that coastal coral reef and ostracode communities experienced a significant reduction in diversity at the end of the Palaeocene [27,73], though the exact role of acidification has yet to be firmly established. In sum, it appears that the direct effects of ocean acidification on marine planktonic calcifiers during the PETM may have been limited because of a relatively 'slow' carbon input rate (slow on human time scales, rapid on geological time scales).…”

“…While the PEB marks a major extinction event of benthic foraminifera, affecting 30-50% of species globally, and the decline of coralgal reefs [25,27,73], most species of calcareous nannoplankton and zooplankton taxa appear to have survived the PEB (see discussion above). Also, terrestrial species experienced only minor extinction [87].…”

A triász és a jura időszak határán lezajlott globális krízis és annak nyomai magyarországi rétegsorokban

“…Ezzel szemben a partközeli élőhelyű és a zátonyszervezetek körében észlelt kihalá sok emelkedése statisztikailag igazolható . A triász-jura tömeges kihalási esemény felte hetően a földtörténet egyik legnagyobb zátonykrízisével esett egybe (KIESSLING & SIMPSON, 2011). Emelett töme gesen tűntek el különösen vastag mészvázat elválasztó (hiperkalcifikáló) fajok a Scleractinia, Bivalvia, Gastro poda csoportokban, míg egyes nem mészvázú formák számot tevő veszteségek nélkül átvészelték a megváltozott környezeti állapotokat (pl.…”