HR: 15:25h
AN: B43G-07    [Abstracts]
TI: Bridging the Reef gaps: first evidence for corals surviving under low pH conditions
AU: * Tchernov, D
EM: dani@vms.huji.ac.il
AF: The Department of Evolution, Systematics and Ecology, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, The Hebrew University of Jerusalem. Berman building, Givat Ram, JR 91904, Israel, Jerusalem, 91904, Israel
AU: * Tchernov, D
EM: dani@vms.huji.ac.il
AF: The Interuniversity Institute for Marine Sciences at Eilat (IUI). H. Steinitz Marine Biology Laboratory., The Interuniversity Institute for Marine Sciences at Eilat (IUI). H. Steinitz Marine Biology Laboratory., Eilat, 88103, Israel
AU: Fine, M
EM: finema@mail.biu.ac.il
AF: AU: Fine, M
EM: finema@mail.biu.ac.il
AF: The Interuniversity Institute for Marine Sciences at Eilat (IUI). H. Steinitz Marine Biology Laboratory., The Interuniversity Institute for Marine Sciences at Eilat (IUI). H. Steinitz Marine Biology Laboratory., Eilat, 88103, Israel
AB: Following two major extinction events, the late Permian and Triassic/Jurassic, there is a long absence of corals from the geological record followed by a recurrence coral fossils. This unusual disappearance and reappearance, referred to commonly as 'reef gaps', was explained as a failure in sampling effort, and/or the movement of these species into geographic 'refugia' that have not been found. Because the phylogeny of recent corals suggests their origin in the pre-Permian-extinction , an alternative explanation for reef gaps hypothesized that corals have a means of alternating between soft bodies and fossilizing forms. This study supports this hypothesis. Thirty coral fragments from 5 coral colonies of the scleractinian Mediterranean corals Oculina patagonica (encrusting) and Madracis pharencis (bulbous) were subjected to pH 7.4-7.6 (in accordance with the pH projected by the IPCC for the year 2300) and 30 fragments to pH 8.0-8.3 (ambient) over a period of 12 months. 100% of the colonies in the experiment and 90% of all polyps survived to the end the experiment. The corals grown in acidified conditions, where skeleton-building conditions were absent, maintained basic life functions as a solitary skeleton-less ecophenotype resembling a sea anemone. On an evolutionary scale, these results provide a possible explanation to coral survival over major extinction events such as the Permian/Triassic and Triassic/Jurassic events. It is important to note that these results only demonstrate that corals can persist as soft bodied ecophoenotypes, but the loss of reef framework has major ramifications to the entire structure and function of coral reef ecosystems, ultimately impacting the services they provide to human society.
DE: 1605 Abrupt/rapid climate change (4901, 8408)
DE: 4853 Photosynthesis
DE: 4916 Corals (4220)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting