Crumbling reefs and cold-water coral habitat loss in a future ocean: evidence of “coralporosis” as an indicator of habitat integrity

Hennige, S. J. et al. (2020) Crumbling reefs and cold-water coral habitat loss in a future ocean: evidence of “coralporosis” as an indicator of habitat integrity. Frontiers in Marine Science, 7, 668. (doi: 10.3389/fmars.2020.00668)

Abstract

Ocean acidification is a threat to the net growth of tropical and deep-sea coral reefs, due to gradual changes in the balance between reef growth and loss processes. Here we go beyond identification of coral dissolution induced by ocean acidification and identify a mechanism that will lead to a loss of habitat in cold-water coral reef habitats on an ecosystem-scale. To quantify this, we present in situ and year-long laboratory evidence detailing the type of habitat shift that can be expected (in situ evidence), the mechanisms underlying this (in situ and laboratory evidence), and the timescale within which the process begins (laboratory evidence). Through application of engineering principals, we detail how increased porosity in structurally critical sections of coral framework will lead to crumbling of load-bearing material, and a potential collapse and loss of complexity of the larger habitat. Importantly, in situ evidence highlights that cold-water corals can survive beneath the aragonite saturation horizon, but in a fundamentally different way to what is currently considered a biogenic cold-water coral reef, with a loss of the majority of reef habitat. The shift from a habitat with high 3-dimensional complexity provided by both live and dead coral framework, to a habitat restricted primarily to live coral colonies with lower 3-dimensional complexity represents the main threat to cold-water coral reefs of the future and the biodiversity they support. Ocean acidification can cause ecosystem-scale habitat loss for the majority of cold-water coral reefs.

• Item Type: Articles
• Additional Information: This work was supported by the Independent Research Fellowship from the Natural Environment Research Council (NERC) to SH (NE/K009028/1 and NE/K009028/2) and the MASTS pooling initiative [The Marine Alliance for Science and Technology for Scotland, funded by the Scottish Funding Council (grant reference HR09011)] and contributing institutions. Experimental incubations for N. Atlantic corals were supported by the UK Ocean Acidification programme (NE/H017305/1 to JMR). Fieldwork in Southern California was supported by NOAA National Centers for Coastal Ocean Science project “Vulnerability of Deep Sea Corals to Ocean Acidification”, with additional funds from South Carolina Sea Grant Graduate Consortium R556, and the PADI Foundation 2013 Grant Award #7904. In kind support was provided by Channel Islands National Marine Sanctuary, National Marine Fisheries Service, and the College of Charleston, SC, United States. UW and AG were supported by the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom under grant no. EP/P005756/1. The study was supported by the Diamond Light Source experimental campaigns MT19794 and MT20412. This manuscript is a contribution to the European Union’s Horizon 2020 Research and Innovation Program under grant agreement No. 678760 (ATLAS) and No. 818123 (iAtlantic), and the UKRI GCRF One Ocean Hub (NE/S008950/1).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Kamenos, Professor Nick
• Authors: Hennige, S. J., Wolfram, U., Wickes, L., Murray, F., Roberts, J. M., Kamenos, N. A., Schofield, S., Groetsch, A., Spiesz, E. M., Aubin-Tam, M.-E., and Etnoyer, P. J.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Frontiers in Marine Science
• Publisher: Frontiers Media
• ISSN: 2296-7745
• ISSN (Online): 2296-7745
• Copyright Holders: Copyright © 2020 Hennige, Wolfram, Wickes, Murray, Roberts, Kamenos, Schofield, Groetsch, Spiesz, Aubin-Tam and Etnoyer
• First Published: First published in Frontiers in Marine Science 7:668
• Publisher Policy: Reproduced under a Creative Commons licence