Please use this identifier to cite or link to this item:
Scopus Web of Science® Altmetric
Type: Journal article
Title: Global regime shift dynamics of catastrophic sea urchin overgrazing
Author: Ling, S.
Scheibling, R.
Rassweiler, A.
Johnson, C.
Shears, N.
Connell, S.
Salomon, A.
Norderhaug, K.
Pérez-Matus, A.
Hernández, J.
Clemente, S.
Blamey, L.
Hereu, B.
Ballesteros, E.
Sala, E.
Garrabou, J.
Cebrian, E.
Zabala, M.
Fujita, D.
Johnson, L.
Citation: Philosophical Transactions of the Royal Society B: Biological Sciences, 2015; 370(1659):1-10
Publisher: Royal Society
Issue Date: 2015
ISSN: 0962-8436
Statement of
S.D. Ling, R.E. Scheibling, A. Rassweiler, C.R. Johnson, N. Shears, S.D. Connell, A.K. Salomon, K.M. Norderhaug, A. Pérez-Matus, J.C. Hernández, S. Clemente, L.K. Blamey, B. Hereu, E. Ballesteros, E. Sala, J. Garrabou, E. Cebrian, M. Zabala, D. Fujita, and L.E. Johnson
Abstract: A pronounced, widespread and persistent regime shift among marine ecosystems is observable on temperate rocky reefs as a result of sea urchin overgrazing. Here, we empirically define regime-shift dynamics for this grazing system which transitions between productive macroalgal beds and impoverished urchin barrens. Catastrophic in nature, urchin overgrazing in a well-studied Australian system demonstrates a discontinuous regime shift, which is of particular management concern as recovery of desirable macroalgal beds requires reducing grazers to well below the initial threshold of overgrazing. Generality of this regime-shift dynamic is explored across 13 rocky reef systems (spanning 11 different regions from both hemispheres) by compiling available survey data (totalling 10 901 quadrats surveyed in situ) plus experimental regime-shift responses (observed during a total of 57 in situ manipulations). The emergent and globally coherent pattern shows urchin grazing to cause a discontinuous ‘catastrophic’ regime shift, with hysteresis effect of approximately one order of magnitude in urchin biomass between critical thresholds of overgrazing and recovery. Different life-history traits appear to create asymmetry in the pace of overgrazing versus recovery. Once shifted, strong feedback mechanisms provide resilience for each alternative state thus defining the catastrophic nature of this regime shift. Importantly, human-derived stressors can act to erode resilience of desirable macroalgal beds while strengthening resilience of urchin barrens, thus exacerbating the risk, spatial extent and irreversibility of an unwanted regime shift for marine ecosystems.
Keywords: Phase-shift; hysteresis; kelp beds; sea urchin barrens; alternative stable states; tipping point
Rights: © 2014 The Author(s) Published by the Royal Society. All rights reserved.
RMID: 0030020098
DOI: 10.1098/rstb.2013.0269
Appears in Collections:Ecology, Evolution and Landscape Science publications

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.