Consumer diversity interacts with prey defenses to drive ecosystem function.
Reads0
Chats0
TLDR
The findings indicate that the total diet breadth of the herbivore community and the probability of all macroalgae being removed from reefs by herbivores increases with increasing Herbivore diversity, but that a few critical species drive this relationship.Abstract:
Prey traits linking consumer diversity to ecosystem function remain poorly understood. On tropical coral reefs, herbivores promote coral dominance by suppressing competing macroalgae, but the roles of herbivore identity and diversity, macroalgal defenses, and their interactions in affecting reef resilience and function are unclear. We studied adjacent pairs of no-take marine reserves and fished areas on reefs in Fiji and found that protected reefs supported 7–17× greater biomass, 2–3× higher species richness of herbivorous fishes, and 3–11× more live coral cover than did fished reefs. In contrast, macroalgae were 27–61× more abundant and 3–4× more species-rich on fished reefs. When we transplanted seven common macroalgae from fished reefs into reserves they were rapidly consumed, suggesting that rates of herbivory (ecosystem functioning) differed inside vs. outside reserves.
We then video-recorded feeding activity on the same seven macroalgae when transplanted into reserves, and assessed the functional redundancy vs. complementarity of herbivorous fishes consuming these macroalgae. Of 29 species of larger herbivorous fishes on these reefs, only four species accounted for 97% of macroalgal consumption. Two unicornfish consumed a range of brown macroalgae, a parrotfish consumed multiple red algae, and a rabbitfish consumed a green alga, with almost no diet overlap among these groups. The two most chemically rich, allelopathic algae were each consumed by a single, but different, fish species. This striking complementarity resulted from herbivore species differing in their tolerances to macroalgal chemical and structural defenses.
A model of assemblage diet breadth based on our feeding observations predicted that high browser diversity would be required for effective control of macroalgae on Fijian reefs. In support of this model, we observed strong negative relationships between herbivore diversity and macroalgal abundance and diversity across the six study reefs. Our findings indicate that the total diet breadth of the herbivore community and the probability of all macroalgae being removed from reefs by herbivores increases with increasing herbivore diversity, but that a few critical species drive this relationship. Therefore, interactions between algal defenses and herbivore tolerances create an essential role for consumer diversity in the functioning and resilience of coral reefs.read more
Citations
More filters
Journal ArticleDOI
Climate-driven regime shift of a temperate marine ecosystem
Thomas Wernberg,Scott Bennett,Scott Bennett,Russell C. Babcock,Russell C. Babcock,Thibaut de Bettignies,Katherine Cure,Katherine Cure,Martial Depczynski,Francois Dufois,Jane Fromont,Christopher J. Fulton,Renae Hovey,Euan S. Harvey,Thomas H. Holmes,Gary A. Kendrick,Ben Radford,Ben Radford,Julia Santana-Garcon,Julia Santana-Garcon,Benjamin J. Saunders,Dan A. Smale,Dan A. Smale,Mads S. Thomsen,Mads S. Thomsen,Chenae A. Tuckett,Fernando Tuya,Mathew A. Vanderklift,Shaun K. Wilson +28 more
TL;DR: It is shown that extreme warming of a temperate kelp forest off Australia resulted not only in its collapse, but also in a shift in community composition that brought about an increase in herbivorous tropical fishes that prevent the reestablishment of kelp.
Journal ArticleDOI
The tropicalization of temperate marine ecosystems: climate-mediated changes in herbivory and community phase shifts
Adriana Vergés,Peter D. Steinberg,Mark E. Hay,Alistair G. B. Poore,Alexandra H. Campbell,Enric Ballesteros,Kenneth L. Heck,David J. Booth,Melinda A. Coleman,David A. Feary,Will F. Figueira,Tim J. Langlois,Ezequiel M. Marzinelli,Toni Mizerek,Peter J. Mumby,Yohei Nakamura,Moninya Roughan,Erik van Sebille,Alex Sen Gupta,Dan A. Smale,Dan A. Smale,Fiona Tomas,Fiona Tomas,Thomas Wernberg,Shaun K. Wilson +24 more
TL;DR: It is argued that this phase shift is facilitated by poleward-flowing boundary currents that are creating ocean warming hotspots around the globe, enabling the range expansion of tropical species and increasing their grazing rates in temperate areas.
Journal ArticleDOI
Predicting climate-driven regime shifts versus rebound potential in coral reefs
Nicholas A. J. Graham,Simon Jennings,Simon Jennings,M. Aaron MacNeil,M. Aaron MacNeil,David Mouillot,David Mouillot,Shaun K. Wilson +7 more
TL;DR: Although conditions governing regime shift or recovery dynamics were diverse, pre-disturbance quantification of simple factors such as structural complexity and water depth accurately predicted ecosystem trajectories, foreshadow the likely divergent but predictable outcomes for reef ecosystems in response to climate change.
Journal ArticleDOI
Long-term empirical evidence of ocean warming leading to tropicalization of fish communities, increased herbivory, and loss of kelp
Adriana Vergés,Christopher Doropoulos,Hamish A. Malcolm,Mathew Skye,Marina Garcia-Pizá,Ezequiel M. Marzinelli,Alexandra H. Campbell,Enric Ballesteros,Andrew S. Hoey,Ana Vila-Concejo,Yves-Marie Bozec,Peter D. Steinberg +11 more
TL;DR: An increase in the proportion of warmwater species (“tropicalization”) as oceans warm is increasing fish herbivory in kelp forests, contributing to their decline and subsequent persistence in alternate “kelp-free” states, and posing a significant threat to kelp-dominated ecosystems in Australia and globally.
Journal ArticleDOI
Recovery potential of the world's coral reef fishes
M. Aaron MacNeil,Nicholas A. J. Graham,Joshua E. Cinner,Shaun K. Wilson,Ivor D. Williams,Joseph Maina,Steven P. Newman,Alan M. Friedlander,Stacy D. Jupiter,Nicholas Polunin,Tim R. McClanahan +10 more
TL;DR: The results demonstrate that crucial ecosystem functions can be maintained through a range of fisheries restrictions, allowing coral reef managers to develop recovery plans that meet conservation and livelihood objectives in areas where marine reserves are not socially or politically feasible solutions.
References
More filters
Journal ArticleDOI
Prey diversity is associated with weaker consumer effects in a meta-analysis of benthic marine experiments.
TL;DR: The effects of species diversity on trophic interactions may scale consistently from small-scale manipulations to cross-community comparisons, and are suggested to be more capable of maintaining abundance via compensatory responses, by containing prey species that are resistant to (or tolerant of) predators.
Journal ArticleDOI
Loss of functionally unique species may gradually undermine ecosystems
Eoin J. O'Gorman,Eoin J. O'Gorman,Jon M. Yearsley,Tasman P. Crowe,Mark C. Emmerson,Ute Jacob,Owen L. Petchey +6 more
TL;DR: It is shown that highly unique species consistently tend to have the weakest mean interaction strength per unit biomass in the system, which appears to be driven by the empirical pattern of size structuring in aquatic systems and the trophic position of each species in the web.
Journal ArticleDOI
Role of Species Diversity and Secondary Compound Complementarity on Diet Selection of Mediterranean Shrubs by Goats
TL;DR: It is suggested that goats can increase intake of Mediterranean shrubs high in secondary compounds by selecting those with different classes of phytotoxins, and biological diversity within Mediterranean maquis vegetation also plays a positive role in increasing shrub intake by goats.
Journal ArticleDOI
Corals fail to recover at a Caribbean marine reserve despite ten years of reserve designation
TL;DR: In this paper, the authors test whether 10 years of reserve designation have translated into positive effects on coral communities in Glover's Reef, Belize, and conclude that regional stressors are overwhelming local management efforts and that additional strategies are required to improve local coral condition.
Journal ArticleDOI
Effects of seaweed extracts and secondary metabolites on feeding by the herbivorous surgeonfish Naso lituratus
TL;DR: The results, together with previous work, suggest that tropical herbivorous fishes differ in their responses to plant chemistry, and this variability precludes broad generalization about the effects of marine plant secondary metabolites on herbivory fishes.