Limits...
Harnessing natural recovery processes to improve restoration outcomes: an experimental assessment of sponge-mediated coral reef restoration.

Biggs BC - PLoS ONE (2013)

Bottom Line: Restoration is increasingly implemented to reestablish habitat structure and function following physical anthropogenic disturbance, but scientific knowledge of effectiveness of methods lags behind demand for guidelines.Differences in overall sponge species performance suggest species selection is important to consider.Employing organisms that jump start successional pathways and facilitate recovery can significantly improve restoration outcomes; however, best practices require techniques be tailored to each system.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Science, Florida State University, Tallahassee, Florida, USA. Biggs@bio.fsu.edu

ABSTRACT

Background: Restoration is increasingly implemented to reestablish habitat structure and function following physical anthropogenic disturbance, but scientific knowledge of effectiveness of methods lags behind demand for guidelines. On coral reefs, recovery is largely dependent on coral reestablishment, and substratum stability is critical to the survival of coral fragments and recruits. Concrete is often used to immobilize rubble, but its ecological performance has not been rigorously evaluated, and restoration has generally fallen short of returning degraded habitat to pre-disturbance conditions. Fragments of erect branching sponges mediate reef recovery by facilitating rubble consolidation, yet such natural processes have been largely overlooked in restoring reefs.

Methods: On two reefs in Curacao, four treatments - coral rubble alone, rubble seeded with sponge fragments, rubble bound by concrete, and concrete "rubble" bound by concrete - were monitored over four years to investigate rubble consolidation with and without sponges and the ecological performance of treatments in terms of the number and diversity of coral recruits. Species specific rates of sponge fragment attachment to rubble, donor sponge growth and tissue replacement, and fragment survival inside rubble piles were also investigated to evaluate sponge species performance and determine rates for sustainably harvesting tissue. FINDINGS/SIGNIFICANCE: Rubble piles seeded with sponges retained height and shape to a significantly greater degree, lost fewer replicates to water motion, and were significantly more likely to be consolidated over time than rubble alone. Significantly more corals recruited to sponge-seeded rubble than to all other treatments. Coral diversity was also greatest for rubble with sponges and it was the only treatment to which framework building corals recruited. Differences in overall sponge species performance suggest species selection is important to consider. Employing organisms that jump start successional pathways and facilitate recovery can significantly improve restoration outcomes; however, best practices require techniques be tailored to each system.

Show MeSH

Related in: MedlinePlus

Number of coral recruits at each site, during each survey, by treatment.A. Sea Aquarium. B. Barracuda point. For Sea Aquarium (A): open, light gray, dark gray and black bars indicate the number of coral recruits at months 12, 24, 36, and 48, respectively. For Barracuda Point (B): open, light gray, dark gray and black bars indicate the number of coral recruits at months 12, 21, 33, and 45, respectively. Letters above black bars (months 48 and 45 for Sea Aquarium and Barracuda Point, respectively), indicate significant differences (P<0.05) among treatments within each site in the number of coral recruits based on pairwise comparison with Bonferroni correction. Within each site, bars that share the same letter are not significantly different (P>0.05) from one another.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3672152&req=5

pone-0064945-g006: Number of coral recruits at each site, during each survey, by treatment.A. Sea Aquarium. B. Barracuda point. For Sea Aquarium (A): open, light gray, dark gray and black bars indicate the number of coral recruits at months 12, 24, 36, and 48, respectively. For Barracuda Point (B): open, light gray, dark gray and black bars indicate the number of coral recruits at months 12, 21, 33, and 45, respectively. Letters above black bars (months 48 and 45 for Sea Aquarium and Barracuda Point, respectively), indicate significant differences (P<0.05) among treatments within each site in the number of coral recruits based on pairwise comparison with Bonferroni correction. Within each site, bars that share the same letter are not significantly different (P>0.05) from one another.

Mentions: Recruitment at SA was initially (month 12) greatest to concrete bound coral rubble; however, its replicates lost recruits and gained fewer new recruits in each successive survey, while sponge-rubble continued to accumulate recruits (Figure 6A). By month 24, and in each successive survey, sponge-rubble had greater numbers of recruits than all other treatments. When compared 48 months after deployment, the number of coral recruits at SA differed significantly among treatments (GLM, F 3, 46 = 10.59, P<0.0001), and a significantly greater number of corals had recruited to sponge-rubble than to all other treatments (Figure 6A). Analyzed over time (repeated measures), treatment itself was not found to significantly influence recruitment (LME, F3, 77 = 1.55, P = 0.208).


Harnessing natural recovery processes to improve restoration outcomes: an experimental assessment of sponge-mediated coral reef restoration.

Biggs BC - PLoS ONE (2013)

Number of coral recruits at each site, during each survey, by treatment.A. Sea Aquarium. B. Barracuda point. For Sea Aquarium (A): open, light gray, dark gray and black bars indicate the number of coral recruits at months 12, 24, 36, and 48, respectively. For Barracuda Point (B): open, light gray, dark gray and black bars indicate the number of coral recruits at months 12, 21, 33, and 45, respectively. Letters above black bars (months 48 and 45 for Sea Aquarium and Barracuda Point, respectively), indicate significant differences (P<0.05) among treatments within each site in the number of coral recruits based on pairwise comparison with Bonferroni correction. Within each site, bars that share the same letter are not significantly different (P>0.05) from one another.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3672152&req=5

pone-0064945-g006: Number of coral recruits at each site, during each survey, by treatment.A. Sea Aquarium. B. Barracuda point. For Sea Aquarium (A): open, light gray, dark gray and black bars indicate the number of coral recruits at months 12, 24, 36, and 48, respectively. For Barracuda Point (B): open, light gray, dark gray and black bars indicate the number of coral recruits at months 12, 21, 33, and 45, respectively. Letters above black bars (months 48 and 45 for Sea Aquarium and Barracuda Point, respectively), indicate significant differences (P<0.05) among treatments within each site in the number of coral recruits based on pairwise comparison with Bonferroni correction. Within each site, bars that share the same letter are not significantly different (P>0.05) from one another.
Mentions: Recruitment at SA was initially (month 12) greatest to concrete bound coral rubble; however, its replicates lost recruits and gained fewer new recruits in each successive survey, while sponge-rubble continued to accumulate recruits (Figure 6A). By month 24, and in each successive survey, sponge-rubble had greater numbers of recruits than all other treatments. When compared 48 months after deployment, the number of coral recruits at SA differed significantly among treatments (GLM, F 3, 46 = 10.59, P<0.0001), and a significantly greater number of corals had recruited to sponge-rubble than to all other treatments (Figure 6A). Analyzed over time (repeated measures), treatment itself was not found to significantly influence recruitment (LME, F3, 77 = 1.55, P = 0.208).

Bottom Line: Restoration is increasingly implemented to reestablish habitat structure and function following physical anthropogenic disturbance, but scientific knowledge of effectiveness of methods lags behind demand for guidelines.Differences in overall sponge species performance suggest species selection is important to consider.Employing organisms that jump start successional pathways and facilitate recovery can significantly improve restoration outcomes; however, best practices require techniques be tailored to each system.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Science, Florida State University, Tallahassee, Florida, USA. Biggs@bio.fsu.edu

ABSTRACT

Background: Restoration is increasingly implemented to reestablish habitat structure and function following physical anthropogenic disturbance, but scientific knowledge of effectiveness of methods lags behind demand for guidelines. On coral reefs, recovery is largely dependent on coral reestablishment, and substratum stability is critical to the survival of coral fragments and recruits. Concrete is often used to immobilize rubble, but its ecological performance has not been rigorously evaluated, and restoration has generally fallen short of returning degraded habitat to pre-disturbance conditions. Fragments of erect branching sponges mediate reef recovery by facilitating rubble consolidation, yet such natural processes have been largely overlooked in restoring reefs.

Methods: On two reefs in Curacao, four treatments - coral rubble alone, rubble seeded with sponge fragments, rubble bound by concrete, and concrete "rubble" bound by concrete - were monitored over four years to investigate rubble consolidation with and without sponges and the ecological performance of treatments in terms of the number and diversity of coral recruits. Species specific rates of sponge fragment attachment to rubble, donor sponge growth and tissue replacement, and fragment survival inside rubble piles were also investigated to evaluate sponge species performance and determine rates for sustainably harvesting tissue. FINDINGS/SIGNIFICANCE: Rubble piles seeded with sponges retained height and shape to a significantly greater degree, lost fewer replicates to water motion, and were significantly more likely to be consolidated over time than rubble alone. Significantly more corals recruited to sponge-seeded rubble than to all other treatments. Coral diversity was also greatest for rubble with sponges and it was the only treatment to which framework building corals recruited. Differences in overall sponge species performance suggest species selection is important to consider. Employing organisms that jump start successional pathways and facilitate recovery can significantly improve restoration outcomes; however, best practices require techniques be tailored to each system.

Show MeSH
Related in: MedlinePlus