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Do behavioral foraging responses of prey to predators function similarly in restored and pristine foodwebs?

Madin EM, Gaines SD, Madin JS, Link AK, Lubchenco PJ, Selden RL, Warner RR - PLoS ONE (2012)

Bottom Line: We compared these responses for two functionally distinct herbivorous prey fishes (the damselfish Plectroglyphidodon dickii and the parrotfish Chlorurus sordidus) within pairs of coral reefs in pristine and restored ecosystems in two regions of these species' biogeographic ranges, allowing us to quantify the magnitude and temporal scale of this key ecosystem variable's recovery.We demonstrate that restoration of top predator abundances also restored prey foraging excursion behaviors to a condition closely resembling those of a pristine ecosystem.Increased understanding of behavioral aspects of ecosystem change will greatly improve our ability to predict the cascading consequences of conservation tools aimed at ecological restoration, such as marine reserves.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, California, United States of America. elizabeth.madin@uts.edu.au

ABSTRACT
Efforts to restore top predators in human-altered systems raise the question of whether rebounds in predator populations are sufficient to restore pristine foodweb dynamics. Ocean ecosystems provide an ideal system to test this question. Removal of fishing in marine reserves often reverses declines in predator densities and size. However, whether this leads to restoration of key functional characteristics of foodwebs, especially prey foraging behavior, is unclear. The question of whether restored and pristine foodwebs function similarly is nonetheless critically important for management and restoration efforts. We explored this question in light of one important determinant of ecosystem function and structure--herbivorous prey foraging behavior. We compared these responses for two functionally distinct herbivorous prey fishes (the damselfish Plectroglyphidodon dickii and the parrotfish Chlorurus sordidus) within pairs of coral reefs in pristine and restored ecosystems in two regions of these species' biogeographic ranges, allowing us to quantify the magnitude and temporal scale of this key ecosystem variable's recovery. We demonstrate that restoration of top predator abundances also restored prey foraging excursion behaviors to a condition closely resembling those of a pristine ecosystem. Increased understanding of behavioral aspects of ecosystem change will greatly improve our ability to predict the cascading consequences of conservation tools aimed at ecological restoration, such as marine reserves.

Show MeSH
Biomass of piscivorous fishes.Piscivorous fish biomass (per unit reef area) at reefs used in this study. Bars are means (±SE).
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pone-0032390-g002: Biomass of piscivorous fishes.Piscivorous fish biomass (per unit reef area) at reefs used in this study. Bars are means (±SE).

Mentions: Here we use a suite of paired fished and unfished reefs to explore the restoration of one key aspect of ecosystem functioning: prey foraging behavior. Specifically, we do so by asking whether differences in prey foraging behavior between a near-pristine system within a marine reserve and its heavily-fished counterpart that had previously been a de facto reserve (due to its geographic isolation) in the Line Islands are similar to differences in prey behavior between reef systems in which protected predator populations have recovered relative to unprotected, fished analogues in the Great Barrier Reef. Figure 1 describes the history of fishing for the suite of reef pairs used in terms of the amount of time elapsed since the onset or cessation of fishing within each pair. Pairs of adjacent reefs under different fishing regimes situated within each of these realms have dramatically different average piscivore biomass as a result of their different fishing histories and regulations (Fig. 2). We show for two functionally-distinct herbivorous fish species that removal of fishing pressure, and the resultant recovery of top predators, leads to restoration of prey foraging behavior that is comparable to those of historically pristine systems, and in particular that this restoration can occur within only a few years of fishing closures.


Do behavioral foraging responses of prey to predators function similarly in restored and pristine foodwebs?

Madin EM, Gaines SD, Madin JS, Link AK, Lubchenco PJ, Selden RL, Warner RR - PLoS ONE (2012)

Biomass of piscivorous fishes.Piscivorous fish biomass (per unit reef area) at reefs used in this study. Bars are means (±SE).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3293809&req=5

pone-0032390-g002: Biomass of piscivorous fishes.Piscivorous fish biomass (per unit reef area) at reefs used in this study. Bars are means (±SE).
Mentions: Here we use a suite of paired fished and unfished reefs to explore the restoration of one key aspect of ecosystem functioning: prey foraging behavior. Specifically, we do so by asking whether differences in prey foraging behavior between a near-pristine system within a marine reserve and its heavily-fished counterpart that had previously been a de facto reserve (due to its geographic isolation) in the Line Islands are similar to differences in prey behavior between reef systems in which protected predator populations have recovered relative to unprotected, fished analogues in the Great Barrier Reef. Figure 1 describes the history of fishing for the suite of reef pairs used in terms of the amount of time elapsed since the onset or cessation of fishing within each pair. Pairs of adjacent reefs under different fishing regimes situated within each of these realms have dramatically different average piscivore biomass as a result of their different fishing histories and regulations (Fig. 2). We show for two functionally-distinct herbivorous fish species that removal of fishing pressure, and the resultant recovery of top predators, leads to restoration of prey foraging behavior that is comparable to those of historically pristine systems, and in particular that this restoration can occur within only a few years of fishing closures.

Bottom Line: We compared these responses for two functionally distinct herbivorous prey fishes (the damselfish Plectroglyphidodon dickii and the parrotfish Chlorurus sordidus) within pairs of coral reefs in pristine and restored ecosystems in two regions of these species' biogeographic ranges, allowing us to quantify the magnitude and temporal scale of this key ecosystem variable's recovery.We demonstrate that restoration of top predator abundances also restored prey foraging excursion behaviors to a condition closely resembling those of a pristine ecosystem.Increased understanding of behavioral aspects of ecosystem change will greatly improve our ability to predict the cascading consequences of conservation tools aimed at ecological restoration, such as marine reserves.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, California, United States of America. elizabeth.madin@uts.edu.au

ABSTRACT
Efforts to restore top predators in human-altered systems raise the question of whether rebounds in predator populations are sufficient to restore pristine foodweb dynamics. Ocean ecosystems provide an ideal system to test this question. Removal of fishing in marine reserves often reverses declines in predator densities and size. However, whether this leads to restoration of key functional characteristics of foodwebs, especially prey foraging behavior, is unclear. The question of whether restored and pristine foodwebs function similarly is nonetheless critically important for management and restoration efforts. We explored this question in light of one important determinant of ecosystem function and structure--herbivorous prey foraging behavior. We compared these responses for two functionally distinct herbivorous prey fishes (the damselfish Plectroglyphidodon dickii and the parrotfish Chlorurus sordidus) within pairs of coral reefs in pristine and restored ecosystems in two regions of these species' biogeographic ranges, allowing us to quantify the magnitude and temporal scale of this key ecosystem variable's recovery. We demonstrate that restoration of top predator abundances also restored prey foraging excursion behaviors to a condition closely resembling those of a pristine ecosystem. Increased understanding of behavioral aspects of ecosystem change will greatly improve our ability to predict the cascading consequences of conservation tools aimed at ecological restoration, such as marine reserves.

Show MeSH