eCite Digital Repository

Overfishing reduces resilience of kelp beds to climate-driven catastrophic phase shift


Ling, SD and Johnson, CR and Frusher, SD and Ridgway, KR, Overfishing reduces resilience of kelp beds to climate-driven catastrophic phase shift, National Academy of Sciences of The United States of America. Proceedings, 106, (52) pp. 22341-22345. ISSN 0027-8424 (2009) [Refereed Article]

Restricted - Request a copy

Copyright Statement

Copyright 2009 National Academy of Sciences. All rights reserved.

Official URL:

DOI: doi:10.1073/pnas.0907529106


A key consideration in assessing impacts of climate change is the possibility of synergistic effects with other human-induced stressors. In the ocean realm, climate change and overfishing pose two of the greatest challenges to the structure and functioning of marine ecosystems. In eastern Tasmania, temperate coastal waters are warming at approximately four times the global ocean warming average, representing the fastest rate of warming in the Southern Hemisphere. This has driven range extension of the ecologically important long-spined sea urchin (Centrostephanus rodgersii), which has now commenced catastrophic overgrazing of productive Tasmanian kelp beds leading to loss of biodiversity and important rocky reef ecosystem services. Coincident with the overgrazing is heavy fishing of reef-based predators including the spiny lobster Jasus edwardsii. By conducting experiments inside and outside Marine Protected Areas we show that fishing, by removing large predatory lobsters, has reduced the resilience of kelp beds against the climate-driven threat of the sea urchin and thus increased risk of catastrophic shift to widespread sea urchin barrens. This shows that interactions between multiple human-induced stressors can exacerbate nonlinear responses of ecosystems to climate change and limit the adaptive capacity of these systems. Management actions focused on reducing the risk of catastrophic phase shift in ecosystems are particularly urgent in the face of ongoing warming and unprecedented levels of predator removal from the world's oceans.

Item Details

Item Type:Refereed Article
Keywords:climate change, overgrazing, sea urchin, temperate reefs, trophic interactions
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Fisheries sciences
Research Field:Aquaculture and fisheries stock assessment
Objective Division:Environmental Management
Objective Group:Terrestrial systems and management
Objective Field:Assessment and management of terrestrial ecosystems
UTAS Author:Ling, SD (Dr Scott Ling)
UTAS Author:Johnson, CR (Professor Craig Johnson)
UTAS Author:Frusher, SD (Professor Stewart Frusher)
ID Code:59769
Year Published:2009
Web of Science® Times Cited:385
Deposited By:Zoology
Deposited On:2009-12-17
Last Modified:2010-05-27
Downloads:2 View Download Statistics

Repository Staff Only: item control page