Habitat collapse due to overgrazing threatens turtle conservation in marine protected areas

Christianen, Marjolijn J. A., Herman, Peter M. J., Bouma, Tjeerd J., Lamers, Leon P. M., van Katwijk, Marieke M., van der Heide, Tjisse, Mumby, Peter J., Silliman, Brian R., Engelhard, Sarah L., van de Kerk, Madelon, Kiswara, Wawan and van de Koppel, Johan (2014) Habitat collapse due to overgrazing threatens turtle conservation in marine protected areas. Proceedings of the Royal Society of London B: Biological Sciences, 281 1777: . doi:10.1098/rspb.2013.2890


Author Christianen, Marjolijn J. A.
Herman, Peter M. J.
Bouma, Tjeerd J.
Lamers, Leon P. M.
van Katwijk, Marieke M.
van der Heide, Tjisse
Mumby, Peter J.
Silliman, Brian R.
Engelhard, Sarah L.
van de Kerk, Madelon
Kiswara, Wawan
van de Koppel, Johan
Title Habitat collapse due to overgrazing threatens turtle conservation in marine protected areas
Journal name Proceedings of the Royal Society of London B: Biological Sciences   Check publisher's open access policy
ISSN 0962-8452
1471-2954
Publication date 2014-01-08
Sub-type Article (original research)
DOI 10.1098/rspb.2013.2890
Volume 281
Issue 1777
Total pages 7
Place of publication London, United Kingdom
Publisher The Royal Society Publishing
Language eng
Abstract Marine protected areas (MPAs) are key tools for combatting the global over-exploitation of endangered species. The prevailing paradigm is that MPAs are beneficial in helping to restore ecosystems to more 'natural' conditions. However, MPAs may have unintended negative effects when increasing densities of protected species exert destructive effects on their habitat. Here, we report on severe seagrass degradation in a decade-old MPA where hyper-abundant green turtles adopted a previously undescribed below-ground foraging strategy. By digging for and consuming rhizomes and roots, turtles create abundant bare gaps, thereby enhancing erosion and reducing seagrass regrowth. A fully parametrized model reveals that the ecosystem is approaching a tipping point, where consumption overwhelms regrowth, which could potentially lead to complete collapse of the seagrass habitat. Seagrass recovery will not ensue unless turtle density is reduced to nearly zero, eliminating the MPA's value as a turtle reserve. Our results reveal an unrecognized, yet imminent threat to MPAs, as sea turtle densities are increasing at major nesting sites and the decline of seagrass habitat forces turtles to concentrate on the remaining meadows inside reserves. This emphasizes the need for policy and management approaches that consider the interactions of protected species with their habitat.
Keyword Alternate stable states
Marine reserves
Plant-herbivore interactions
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2015 Collection
School of Biological Sciences Publications
 
Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 19 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 27 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Tue, 28 Jan 2014, 10:24:50 EST by System User on behalf of School of Biological Sciences