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Humans and seasonal climate variability threaten large-bodied coral reef fish with small ranges. Nat Commun 2016; 7:10491. [PMID: 26839155 PMCID: PMC4742806 DOI: 10.1038/ncomms10491] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 12/18/2015] [Indexed: 12/17/2022] Open
Abstract
Coral reefs are among the most species-rich and threatened ecosystems on Earth, yet the extent to which human stressors determine species occurrences, compared with biogeography or environmental conditions, remains largely unknown. With ever-increasing human-mediated disturbances on these ecosystems, an important question is not only how many species can inhabit local communities, but also which biological traits determine species that can persist (or not) above particular disturbance thresholds. Here we show that human pressure and seasonal climate variability are disproportionately and negatively associated with the occurrence of large-bodied and geographically small-ranging fishes within local coral reef communities. These species are 67% less likely to occur where human impact and temperature seasonality exceed critical thresholds, such as in the marine biodiversity hotspot: the Coral Triangle. Our results identify the most sensitive species and critical thresholds of human and climatic stressors, providing opportunity for targeted conservation intervention to prevent local extinctions. Knowing which species traits may confer resilience to human-mediated stressors will help predict future impacts on biodiversity. Here, Mellin et al. show that large bodied fish with small geographic ranges are disproportionately affected by the negative impacts of human disturbance and climate variability.
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McClanahan TR, Muthiga NA, Abunge C, Kamukuru AT, Mwakalapa E, Kalombo H. What Happens after Conservation and Management Donors Leave? A Before and After Study of Coral Reef Ecology and Stakeholder Perceptions of Management Benefits. PLoS One 2015; 10:e0138769. [PMID: 26469979 PMCID: PMC4607501 DOI: 10.1371/journal.pone.0138769] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 09/03/2015] [Indexed: 11/29/2022] Open
Abstract
The coral reefs of Tanga, Tanzania were recognized as a national conservation priority in the early 1970s, but the lack of a management response led to damage by dynamite, beach seines, and high numbers of fishers until the mid 1990s. Subsequently, an Irish Aid funded IUCN Eastern Africa program operated from 1994 to mid 2007 to implement increased management aimed at reducing these impacts. The main effects of this management were to establish collaborative management areas, reduce dynamite and seine net fishing, and establish small community fisheries closures beginning in 1996. The ecology of the coral reefs was studied just prior to the initiation of this management in 1996, during, 2004, and a few years after the project ended in 2010. The perceptions of resource users towards management options were evaluated in 2010. The ecological studies indicated that the biomass of fish rose continuously during this period from 260 to 770 kg/ha but the small closures were no different from the non-closure areas. The benthic community studies indicate stability in the coral cover and community composition and an increase in coralline algae and topographic complexity over time. The lack of change in the coral community suggests resilience to various disturbances including fisheries management and the warm temperature anomaly of 1998. These results indicate that some aspects of the management program had been ecologically successful even after the donor program ended. Moreover, the increased compliance with seine net use and dynamite restrictions were the most likely factors causing this increase in fish biomass and not the closures. Resource users interviewed in 2010 were supportive of gear restrictions but there was considerable between-community disagreement over the value of specific restrictions. The social-ecological results suggest that increased compliance with gear restrictions is largely responsible for the improvements in reef ecology and is a high priority for future management programs.
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Affiliation(s)
- Timothy R McClanahan
- Wildlife Conservation Society, Marine Program, Bronx, NY, United States of America; Wildlife Conservation Society, Marine Program, Mombasa, Kenya
| | - Nyawira A Muthiga
- Wildlife Conservation Society, Marine Program, Bronx, NY, United States of America; Wildlife Conservation Society, Marine Program, Mombasa, Kenya
| | - Caroline Abunge
- Wildlife Conservation Society, Marine Program, Mombasa, Kenya
| | - Albogast T Kamukuru
- University of Dar es Salaam, Department of Aquatic Sciences and Fisheries, Dar es Salaam, Tanzania
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Caselle JE, Rassweiler A, Hamilton SL, Warner RR. Recovery trajectories of kelp forest animals are rapid yet spatially variable across a network of temperate marine protected areas. Sci Rep 2015; 5:14102. [PMID: 26373803 PMCID: PMC4642697 DOI: 10.1038/srep14102] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 08/18/2015] [Indexed: 11/17/2022] Open
Abstract
Oceans currently face a variety of threats, requiring ecosystem-based approaches to management such as networks of marine protected areas (MPAs). We evaluated changes in fish biomass on temperate rocky reefs over the decade following implementation of a network of MPAs in the northern Channel Islands, California. We found that the biomass of targeted (i.e. fished) species has increased consistently inside all MPAs in the network, with an effect of geography on the strength of the response. More interesting, biomass of targeted fish species also increased outside MPAs, although only 27% as rapidly as in the protected areas, indicating that redistribution of fishing effort has not severely affected unprotected populations. Whether the increase outside of MPAs is due to changes in fishing pressure, fisheries management actions, adult spillover, favorable environmental conditions, or a combination of all four remains unknown. We evaluated methods of controlling for biogeographic or environmental variation across networks of protected areas and found similar performance of models incorporating empirical sea surface temperature versus a simple geographic blocking term based on assemblage structure. The patterns observed are promising indicators of the success of this network, but more work is needed to understand how ecological and physical contexts affect MPA performance.
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Affiliation(s)
- Jennifer E. Caselle
- Marine Science Institute, University of California, Santa Barbara, CA 93106 USA
| | - Andrew Rassweiler
- Marine Science Institute, University of California, Santa Barbara, CA 93106 USA
| | - Scott L. Hamilton
- Moss Landing Marine Laboratories, 8272 Moss Landing Rd., Moss Landing, CA 95039 USA
| | - Robert R. Warner
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106 USA
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Species distribution models of tropical deep-sea snappers. PLoS One 2015; 10:e0127395. [PMID: 26030067 PMCID: PMC4451071 DOI: 10.1371/journal.pone.0127395] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 04/15/2015] [Indexed: 11/19/2022] Open
Abstract
Deep-sea fisheries provide an important source of protein to Pacific Island countries and territories that are highly dependent on fish for food security. However, spatial management of these deep-sea habitats is hindered by insufficient data. We developed species distribution models using spatially limited presence data for the main harvested species in the Western Central Pacific Ocean. We used bathymetric and water temperature data to develop presence-only species distribution models for the commercially exploited deep-sea snappers Etelis Cuvier 1828, Pristipomoides Valenciennes 1830, and Aphareus Cuvier 1830. We evaluated the performance of four different algorithms (CTA, GLM, MARS, and MAXENT) within the BIOMOD framework to obtain an ensemble of predicted distributions. We projected these predictions across the Western Central Pacific Ocean to produce maps of potential deep-sea snapper distributions in 32 countries and territories. Depth was consistently the best predictor of presence for all species groups across all models. Bathymetric slope was consistently the poorest predictor. Temperature at depth was a good predictor of presence for GLM only. Model precision was highest for MAXENT and CTA. There were strong regional patterns in predicted distribution of suitable habitat, with the largest areas of suitable habitat (> 35% of the Exclusive Economic Zone) predicted in seven South Pacific countries and territories (Fiji, Matthew & Hunter, Nauru, New Caledonia, Tonga, Vanuatu and Wallis & Futuna). Predicted habitat also varied among species, with the proportion of predicted habitat highest for Aphareus and lowest for Etelis. Despite data paucity, the relationship between deep-sea snapper presence and their environments was sufficiently strong to predict their distribution across a large area of the Pacific Ocean. Our results therefore provide a strong baseline for designing monitoring programs that balance resource exploitation and conservation planning, and for predicting future distributions of deep-sea snappers.
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da Silva IM, Hill N, Shimadzu H, Soares AMVM, Dornelas M. Spillover effects of a community-managed marine reserve. PLoS One 2015; 10:e0111774. [PMID: 25927235 PMCID: PMC4415971 DOI: 10.1371/journal.pone.0111774] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Accepted: 10/07/2014] [Indexed: 11/29/2022] Open
Abstract
The value of no-take marine reserves as fisheries-management tools is controversial, particularly in high-poverty areas where human populations depend heavily on fish as a source of protein. Spillover, the net export of adult fish, is one mechanism by which no-take marine reserves may have a positive influence on adjacent fisheries. Spillover can contribute to poverty alleviation, although its effect is modulated by the number of fishermen and fishing intensity. In this study, we quantify the effects of a community-managed marine reserve in a high poverty area of Northern Mozambique. For this purpose, underwater visual censuses of reef fish were undertaken at three different times: 3 years before (2003), at the time of establishment (2006) and 6 years after the marine reserve establishment (2012). The survey locations were chosen inside, outside and on the border of the marine reserve. Benthic cover composition was quantified at the same sites in 2006 and 2012. After the reserve establishment, fish sizes were also estimated. Regression tree models show that the distance from the border and the time after reserve establishment were the variables with the strongest effect on fish abundance. The extent and direction of the spillover depends on trophic group and fish size. Poisson Generalized Linear Models show that, prior to the reserve establishment, the survey sites did not differ but, after 6 years, the abundance of all fish inside the reserve has increased and caused spillover of herbivorous fish. Spillover was detected 1km beyond the limit of the reserve for small herbivorous fishes. Six years after the establishment of a community-managed reserve, the fish assemblages have changed dramatically inside the reserve, and spillover is benefitting fish assemblages outside the reserve.
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Affiliation(s)
- Isabel Marques da Silva
- Departamento de Zoologia, Universidade do Lúrio, Pemba, Mozambique and Departamento de Biologia, Universidade de Aveiro, Aveiro, Portugal
- * E-mail:
| | - Nick Hill
- Conservation Programmes, Zoological Society of London, London, England, United Kingdom
| | - Hideyasu Shimadzu
- Centre for Biological Diversity and Scottish Oceans Institute, School of Biology, University of St. Andrews, St. Andrews, Scotland, United Kingdom
| | | | - Maria Dornelas
- Centre for Biological Diversity and Scottish Oceans Institute, School of Biology, University of St. Andrews, St. Andrews, Scotland, United Kingdom
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Recovery potential of the world's coral reef fishes. Nature 2015; 520:341-4. [PMID: 25855298 DOI: 10.1038/nature14358] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 02/27/2015] [Indexed: 11/09/2022]
Abstract
Continuing degradation of coral reef ecosystems has generated substantial interest in how management can support reef resilience. Fishing is the primary source of diminished reef function globally, leading to widespread calls for additional marine reserves to recover fish biomass and restore key ecosystem functions. Yet there are no established baselines for determining when these conservation objectives have been met or whether alternative management strategies provide similar ecosystem benefits. Here we establish empirical conservation benchmarks and fish biomass recovery timelines against which coral reefs can be assessed and managed by studying the recovery potential of more than 800 coral reefs along an exploitation gradient. We show that resident reef fish biomass in the absence of fishing (B0) averages ∼1,000 kg ha(-1), and that the vast majority (83%) of fished reefs are missing more than half their expected biomass, with severe consequences for key ecosystem functions such as predation. Given protection from fishing, reef fish biomass has the potential to recover within 35 years on average and less than 60 years when heavily depleted. Notably, alternative fisheries restrictions are largely (64%) successful at maintaining biomass above 50% of B0, sustaining key functions such as herbivory. Our 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.
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Hehre EJ, Meeuwig JJ. Differential response of fish assemblages to coral reef-based seaweed farming. PLoS One 2015; 10:e0118838. [PMID: 25822342 PMCID: PMC4378911 DOI: 10.1371/journal.pone.0118838] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 01/21/2015] [Indexed: 11/19/2022] Open
Abstract
As the global demand for seaweed-derived products drives the expansion of seaweed farming onto shallow coral ecosystems, the effects of farms on fish assemblages remain largely unexplored. Shallow coral reefs provide food and shelter for highly diverse fish assemblages but are increasingly modified by anthropogenic activities. We hypothesized that the introduction of seaweed farms into degraded shallow coral reefs had potential to generate ecological benefits for fish by adding structural complexity and a possible food source. We conducted 210 transects at 14 locations, with sampling stratified across seaweed farms and sites adjacent to and distant from farms. At a seascape scale, locations were classified by their level of exposure to human disturbance. We compared sites where (1) marine protected areas (MPAs) were established, (2) neither MPAs nor blast fishing was present (hence “unprotected”), and (3) blast fishing occurred. We observed 80,186 fish representing 148 species from 38 families. The negative effects of seaweed farms on fish assemblages appeared stronger in the absence of blast fishing and were strongest when MPAs were present, likely reflecting the positive influence of the MPAs on fish within them. Species differentiating fish assemblages with respect to seaweed farming and disturbance were typically small but also included two key target species. The propensity for seaweed farms to increase fish diversity, abundance, and biomass is limited and may reduce MPA benefits. We suggest that careful consideration be given to the placement of seaweed farms relative to MPAs.
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Affiliation(s)
- E. James Hehre
- Sea Around Us Project /Fisheries Center, University of British Columbia, Vancouver, BC, Canada
- * E-mail:
| | - J. J. Meeuwig
- School of Animal Biology and Centre for Marine Futures (Oceans Institute), University of Western Australia, Crawley, WA, Australia
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Emslie MJ, Logan M, Williamson DH, Ayling AM, MacNeil MA, Ceccarelli D, Cheal AJ, Evans RD, Johns KA, Jonker MJ, Miller IR, Osborne K, Russ GR, Sweatman HPA. Expectations and Outcomes of Reserve Network Performance following Re-zoning of the Great Barrier Reef Marine Park. Curr Biol 2015; 25:983-92. [PMID: 25819564 DOI: 10.1016/j.cub.2015.01.073] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Revised: 12/16/2014] [Accepted: 01/30/2015] [Indexed: 11/25/2022]
Abstract
Networks of no-take marine reserves (NTMRs) are widely advocated for preserving exploited fish stocks and for conserving biodiversity. We used underwater visual surveys of coral reef fish and benthic communities to quantify the short- to medium-term (5 to 30 years) ecological effects of the establishment of NTMRs within the Great Barrier Reef Marine Park (GBRMP). The density, mean length, and biomass of principal fishery species, coral trout (Plectropomus spp., Variola spp.), were consistently greater in NTMRs than on fished reefs over both the short and medium term. However, there were no clear or consistent differences in the structure of fish or benthic assemblages, non-target fish density, fish species richness, or coral cover between NTMR and fished reefs. There was no indication that the displacement and concentration of fishing effort reduced coral trout populations on fished reefs. A severe tropical cyclone impacted many survey reefs during the study, causing similar declines in coral cover and fish density on both NTMR and fished reefs. However, coral trout biomass declined only on fished reefs after the cyclone. The GBRMP is performing as expected in terms of the protection of fished stocks and biodiversity for a developed country in which fishing is not excessive and targets a narrow range of species. NTMRs cannot protect coral reefs directly from acute regional-scale disturbance but, after a strong tropical cyclone, impacted NTMR reefs supported higher biomass of key fishery-targeted species and so should provide valuable sources of larvae to enhance population recovery and long-term persistence.
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Affiliation(s)
- Michael J Emslie
- Australian Institute of Marine Science, PMB No. 3, Townsville MC, Townsville, QLD 4810, Australia.
| | - Murray Logan
- Australian Institute of Marine Science, PMB No. 3, Townsville MC, Townsville, QLD 4810, Australia
| | - David H Williamson
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia; College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia
| | - Anthony M Ayling
- Sea Research, 20 Rattray Avenue, Hideaway Bay, QLD 4800, Australia
| | - M Aaron MacNeil
- Australian Institute of Marine Science, PMB No. 3, Townsville MC, Townsville, QLD 4810, Australia
| | - Daniela Ceccarelli
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
| | - Alistair J Cheal
- Australian Institute of Marine Science, PMB No. 3, Townsville MC, Townsville, QLD 4810, Australia
| | - Richard D Evans
- Department of Parks and Wildlife, 17 Dick Perry Avenue, Kensington, Perth, WA 6151, Australia; Oceans Institute, University of Western Australia, Crawley, WA 6009, Australia
| | - Kerryn A Johns
- Australian Institute of Marine Science, PMB No. 3, Townsville MC, Townsville, QLD 4810, Australia
| | - Michelle J Jonker
- Australian Institute of Marine Science, PMB No. 3, Townsville MC, Townsville, QLD 4810, Australia
| | - Ian R Miller
- Australian Institute of Marine Science, PMB No. 3, Townsville MC, Townsville, QLD 4810, Australia
| | - Kate Osborne
- Australian Institute of Marine Science, PMB No. 3, Townsville MC, Townsville, QLD 4810, Australia
| | - Garry R Russ
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia; College of Marine and Environmental Sciences, James Cook University, Townsville, QLD 4811, Australia
| | - Hugh P A Sweatman
- Australian Institute of Marine Science, PMB No. 3, Townsville MC, Townsville, QLD 4810, Australia
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Karr KA, Fujita R, Halpern BS, Kappel CV, Crowder L, Selkoe KA, Alcolado PM, Rader D. Thresholds in Caribbean coral reefs: implications for ecosystem-based fishery management. J Appl Ecol 2015. [DOI: 10.1111/1365-2664.12388] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kendra A. Karr
- Oceans Program; Environmental Defense Fund; 123 Mission Street 28th Floor San Francisco CA 94105 USA
- Ecology and Evolutionary Biology; 100 Shaffer Road, University of California Santa Cruz; Santa Cruz CA 95064 USA
| | - Rod Fujita
- Oceans Program; Environmental Defense Fund; 123 Mission Street 28th Floor San Francisco CA 94105 USA
- Center for Ocean Solutions; Woods Institute for the Environment; Stanford University; 99 Pacific St. Suite 555E Monterey CA 93940 USA
| | - Benjamin S. Halpern
- National Center for Ecological Analysis and Synthesis; 735 State St. Suite 300 Santa Barbara CA 93101 USA
- Bren School of Environmental Science and Management; University of California; Santa Barbara CA 93016 USA
- Imperial College London; Silwood Park Campus Buckhurst Road Ascot SL5 7PY UK
| | - Carrie V. Kappel
- National Center for Ecological Analysis and Synthesis; 735 State St. Suite 300 Santa Barbara CA 93101 USA
| | - Larry Crowder
- Center for Ocean Solutions; Woods Institute for the Environment; Stanford University; 99 Pacific St. Suite 555E Monterey CA 93940 USA
| | - Kimberly A. Selkoe
- National Center for Ecological Analysis and Synthesis; 735 State St. Suite 300 Santa Barbara CA 93101 USA
- Hawaii Institute of Marine Biology; University of Hawai'i; Kane'ohe HI 97644 USA
| | - Pedro M. Alcolado
- Instituto de Oceanologia; Calle 1ra. E No. 18406 Playa Ciudad Habana Cuba
| | - Doug Rader
- Oceans Program; Environmental Defense Fund; 4000 Westchase Blvd. Suite 510 Raleigh NC 27607 USA
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Response of rocky reef top predators (Serranidae: Epinephelinae) in and around marine protected areas in the Western Mediterranean Sea. PLoS One 2014; 9:e98206. [PMID: 24905331 PMCID: PMC4048186 DOI: 10.1371/journal.pone.0098206] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 04/30/2014] [Indexed: 11/20/2022] Open
Abstract
Groupers species are extremely vulnerable to overfishing and many species are threatened worldwide. In recent decades, Mediterranean groupers experienced dramatic population declines. Marine protected areas (MPAs) can protect populations inside their boundaries and provide individuals to adjacent fishing areas through the process of spillover and larval export. This study aims to evaluate the effectiveness of six marine reserves in the Western Mediterranean Sea to protect the populations of three species of grouper, Epinephelus marginatus, Epinephelus costae and Mycteroperca rubra, and to understand in which circumstances MPAs are able to export biomass to neighbouring areas. All the studied MPAs, except one where no grouper was observed, were able to maintain high abundance, biomass and mean weight of groupers. Size classes were more evenly distributed inside than outside MPAs. In two reserves, biomass gradients could be detected through the boundaries of the reserve as an indication of spillover. In some cases, habitat structure appeared to exert a great influence on grouper abundance, biomass and mean individual weight, influencing the gradient shape. Because groupers are generally sedentary animals with a small home range, we suggest that biomass gradients could only occur where groupers attain sufficient abundance inside MPA limits, indicating a strongly density-dependent process.
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Valdivia A, Bruno JF, Cox CE, Hackerott S, Green SJ. Re-examining the relationship between invasive lionfish and native grouper in the Caribbean. PeerJ 2014; 2:e348. [PMID: 24765582 PMCID: PMC3994649 DOI: 10.7717/peerj.348] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 03/25/2014] [Indexed: 11/20/2022] Open
Abstract
Biotic resistance is the idea that native species negatively affect the invasion success of introduced species, but whether this can occur at large spatial scales is poorly understood. Here we re-evaluated the hypothesis that native large-bodied grouper and other predators are controlling the abundance of exotic lionfish (Pterois volitans/miles) on Caribbean coral reefs. We assessed the relationship between the biomass of lionfish and native predators at 71 reefs in three biogeographic regions while taking into consideration several cofactors that may affect fish abundance, including among others, proxies for fishing pressure and habitat structural complexity. Our results indicate that the abundance of lionfish, large-bodied grouper and other predators were not negatively related. Lionfish abundance was instead controlled by several physical site characteristics, and possibly by culling. Taken together, our results suggest that managers cannot rely on current native grouper populations to control the lionfish invasion.
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Affiliation(s)
- Abel Valdivia
- Department of Biology, The University of North Carolina at Chapel Hill , Chapel Hill, NC , USA
| | - John F Bruno
- Department of Biology, The University of North Carolina at Chapel Hill , Chapel Hill, NC , USA
| | - Courtney E Cox
- Department of Biology, The University of North Carolina at Chapel Hill , Chapel Hill, NC , USA
| | - Serena Hackerott
- Department of Biology, The University of North Carolina at Chapel Hill , Chapel Hill, NC , USA
| | - Stephanie J Green
- Department of Zoology, Oregon State University , Corvallis, OR , USA
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62
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Lindfield SJ, McIlwain JL, Harvey ES. Depth refuge and the impacts of SCUBA spearfishing on coral reef fishes. PLoS One 2014; 9:e92628. [PMID: 24663400 PMCID: PMC3963921 DOI: 10.1371/journal.pone.0092628] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 02/23/2014] [Indexed: 11/18/2022] Open
Abstract
In recent decades, spearfishing with SCUBA has emerged as an efficient method for targeting reef fish in deeper waters. However, deeper waters are increasingly recognised as a potential source of refuge that may help sustain fishery resources. We used a combination of historical catch data over a 20-year time period and fishery-independent surveys to investigate the effects of SCUBA spearfishing on coral reef fish populations in the southern Mariana Islands. Two jurisdictions were studied; Guam, where SCUBA spearfishing is practiced, and the nearby Commonwealth of Northern Mariana Islands (CNMI), where SCUBA spearfishing has been banned since 2003. Fishery-independent data were collected using baited remote underwater stereo-video systems (stereo-BRUVs) stratified by depth, marine protected area status and jurisdiction. Herbivores (primary consumers) dominated spearfishing catches, with parrotfish (scarines) and surgeonfish/unicornfish (acanthurids) the main groups harvested. However, the large, endangered humphead wrasse (Cheilinus undulatus) was the main species by weight landed by SCUBA spearfishers. SCUBA spearfishing was associated with declining size of scarines over time and catches shifting from a dominance of large parrotfishes to a mixed assemblage with increasing proportions of acanthurids. Comparisons between Guam and the nearby CNMI revealed differences in the assemblage of fished species and also greater size of scarines and acanthurids in deep water where SCUBA fishing is banned. These results suggest that SCUBA spearfishing impacts reef fish populations and that the restriction of this fishing method will ensure refuge for fish populations in deeper waters. We recommend a ban on SCUBA spearfishing to preserve or aid the recovery of large, functionally important coral reef species and to improve the sustainability of coral reef fisheries.
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Affiliation(s)
- Steven J. Lindfield
- The UWA Oceans Institute and School of Plant Biology, Faculty of Natural and Agricultural Sciences, The University of Western Australia, Crawley, Western Australia, Australia
- * E-mail:
| | - Jennifer L. McIlwain
- Department of Environment and Agriculture, Curtin University, Bentley, Western Australia, Australia
| | - Euan S. Harvey
- Department of Environment and Agriculture, Curtin University, Bentley, Western Australia, Australia
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Taylor BM, Choat JH. Comparative demography of commercially important parrotfish species from Micronesia. JOURNAL OF FISH BIOLOGY 2014; 84:383-402. [PMID: 24446696 DOI: 10.1111/jfb.12294] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 11/06/2013] [Indexed: 06/03/2023]
Abstract
Fishery-independent sampling was used to determine growth patterns, life span, mortality rates and timing of maturation and sex change in 12 common parrotfishes (Labridae: tribe Scarinae) from five genera (Calotomus, Cetoscarus, Chlorurus, Hipposcarus and Scarus) in Micronesia. Interspecific variation in life-history traits was explored using multivariate analysis. All species displayed strong sex-specific patterns of length-at-age among which males reached larger asymptotic lengths. There was a high level of correlation among life-history traits across species. Relationships between length-based and age-based variables were weakest, with a tenuous link between maximum body size and life span. Cluster analysis based on similarities among life-history traits demonstrated that species were significantly grouped at two major levels. The first grouping was driven by length-based variables (lengths at maturity and sex change and maximum length) and separated the small- and large-bodied species. Within these, species were grouped by age-based variables (age at maturity, mortality and life span). Groupings based on demographic and life-history features were independent of phylogenetic relationships at the given taxonomic level. The results reiterate that body size is an important characteristic differentiating species, but interspecific variation in age-based traits complicates its use as a life-history proxy. Detailed life-history metrics should facilitate future quantitative assessments of vulnerability to overexploitation in multispecies fisheries.
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Affiliation(s)
- B M Taylor
- School of Marine and Tropical Biology, James Cook University, Townsville, Qld 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Qld 4811, Australia
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64
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Vallès H, Oxenford HA. Parrotfish size: a simple yet useful alternative indicator of fishing effects on Caribbean reefs? PLoS One 2014; 9:e86291. [PMID: 24466009 PMCID: PMC3896469 DOI: 10.1371/journal.pone.0086291] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 12/11/2013] [Indexed: 11/19/2022] Open
Abstract
There is great need to identify simple yet reliable indicators of fishing effects within the multi-species, multi-gear, data-poor fisheries of the Caribbean. Here, we investigate links between fishing pressure and three simple fish metrics, i.e. average fish weight (an estimate of average individual fish size), fish density and fish biomass, derived from (1) the parrotfish family, a ubiquitous herbivore family across the Caribbean, and (2) three fish groups of "commercial" carnivores including snappers and groupers, which are widely-used as indicators of fishing effects. We hypothesize that, because most Caribbean reefs are being heavily fished, fish metrics derived from the less vulnerable parrotfish group would exhibit stronger relationships with fishing pressure on today's Caribbean reefs than those derived from the highly vulnerable commercial fish groups. We used data from 348 Atlantic and Gulf Rapid Reef Assessment (AGRRA) reef-surveys across the Caribbean to assess relationships between two independent indices of fishing pressure (one derived from human population density data, the other from open to fishing versus protected status) and the three fish metrics derived from the four aforementioned fish groups. We found that, although two fish metrics, average parrotfish weight and combined biomass of selected commercial species, were consistently negatively linked to the indices of fishing pressure across the Caribbean, the parrotfish metric consistently outranked the latter in the strength of the relationship, thus supporting our hypothesis. Overall, our study highlights that (assemblage-level) average parrotfish size might be a useful alternative indicator of fishing effects over the typical conditions of most Caribbean shallow reefs: moderate-to-heavy levels of fishing and low abundance of highly valued commercial species.
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Affiliation(s)
- Henri Vallès
- Department of Biological and Chemical Sciences, The University of the West Indies, Cave Hill Campus, Cave Hill, Barbados
| | - Hazel A. Oxenford
- Centre for Resource Management and Environmental Studies (CERMES), The University of the West Indies, Cave Hill Campus, Cave Hill, Barbados
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Williamson DH, Ceccarelli DM, Evans RD, Jones GP, Russ GR. Habitat dynamics, marine reserve status, and the decline and recovery of coral reef fish communities. Ecol Evol 2014; 4:337-54. [PMID: 24634720 PMCID: PMC3936382 DOI: 10.1002/ece3.934] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 11/26/2013] [Accepted: 11/29/2013] [Indexed: 11/08/2022] Open
Abstract
Severe climatic disturbance events often have major impacts on coral reef communities, generating cycles of decline and recovery, and in some extreme cases, community-level phase shifts from coral-to algal-dominated states. Benthic habitat changes directly affect reef fish communities, with low coral cover usually associated with low fish diversity and abundance. No-take marine reserves (NTRs) are widely advocated for conserving biodiversity and enhancing the sustainability of exploited fish populations. Numerous studies have documented positive ecological and socio-economic benefits of NTRs; however, the ability of NTRs to ameliorate the effects of acute disturbances on coral reefs has seldom been investigated. Here, we test these factors by tracking the dynamics of benthic and fish communities, including the important fishery species, coral trout (Plectropomus spp.), over 8 years in both NTRs and fished areas in the Keppel Island group, Great Barrier Reef, Australia. Two major disturbances impacted the reefs during the monitoring period, a coral bleaching event in 2006 and a freshwater flood plume in 2011. Both disturbances generated significant declines in coral cover and habitat complexity, with subsequent declines in fish abundance and diversity, and pronounced shifts in fish assemblage structure. Coral trout density also declined in response to the loss of live coral, however, the approximately 2:1 density ratio between NTRs and fished zones was maintained over time. The only post-disturbance refuges for coral trout spawning stocks were within the NTRs that escaped the worst effects of the disturbances. Although NTRs had little discernible effect on the temporal dynamics of benthic or fish communities, it was evident that the post-disturbance refuges for coral trout spawning stocks within some NTRs may be critically important to regional-scale population persistence and recovery.
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Affiliation(s)
- David H Williamson
- ARC Centre of Excellence for Coral Reef Studies, James Cook University Townsville, Queensland, 4811, Australia
| | - Daniela M Ceccarelli
- ARC Centre of Excellence for Coral Reef Studies, James Cook University Townsville, Queensland, 4811, Australia
| | - Richard D Evans
- Department of Parks & Wildlife 17 Dick Perry Ave., Kensington, Perth, Western Australia, 6151, Australia ; Oceans Institute, School of Plant Biology, University of Western Australia Crawley, Western Australia, 6009, Australia
| | - Geoffrey P Jones
- ARC Centre of Excellence for Coral Reef Studies, James Cook University Townsville, Queensland, 4811, Australia ; School of Marine and Tropical Biology, James Cook University Townsville, Queensland, 4811, Australia
| | - Garry R Russ
- ARC Centre of Excellence for Coral Reef Studies, James Cook University Townsville, Queensland, 4811, Australia ; School of Marine and Tropical Biology, James Cook University Townsville, Queensland, 4811, Australia
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66
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Edwards CB, Friedlander AM, Green AG, Hardt MJ, Sala E, Sweatman HP, Williams ID, Zgliczynski B, Sandin SA, Smith JE. Global assessment of the status of coral reef herbivorous fishes: evidence for fishing effects. Proc Biol Sci 2014; 281:20131835. [PMID: 24258715 PMCID: PMC3843826 DOI: 10.1098/rspb.2013.1835] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 10/04/2013] [Indexed: 11/12/2022] Open
Abstract
On coral reefs, herbivorous fishes consume benthic primary producers and regulate competition between fleshy algae and reef-building corals. Many of these species are also important fishery targets, yet little is known about their global status. Using a large-scale synthesis of peer-reviewed and unpublished data, we examine variability in abundance and biomass of herbivorous reef fishes and explore evidence for fishing impacts globally and within regions. We show that biomass is more than twice as high in locations not accessible to fisheries relative to fisheries-accessible locations. Although there are large biogeographic differences in total biomass, the effects of fishing are consistent in nearly all regions. We also show that exposure to fishing alters the structure of the herbivore community by disproportionately reducing biomass of large-bodied functional groups (scraper/excavators, browsers, grazer/detritivores), while increasing biomass and abundance of territorial algal-farming damselfishes (Pomacentridae). The browser functional group that consumes macroalgae and can help to prevent coral-macroalgal phase shifts appears to be most susceptible to fishing. This fishing down the herbivore guild probably alters the effectiveness of these fishes in regulating algal abundance on reefs. Finally, data from remote and unfished locations provide important baselines for setting management and conservation targets for this important group of fishes.
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Affiliation(s)
- C. B. Edwards
- Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0202, USA
| | - A. M. Friedlander
- U.S. Geological Survey, Hawaii Cooperative Fishery Research Unit, University of Hawaii at Manoa, Honolulu, HI 96822, USA
| | - A. G. Green
- The Nature Conservancy, Brisbane, Queensland 4101, Australia
| | | | - E. Sala
- National Geographic Society, Washington, DC 20090, USA
| | - H. P. Sweatman
- Australian Institute of Marine Science, TMC, Townsville, Queensland 4810, Australia
| | - I. D. Williams
- Pacific Islands Fisheries Science Center, Coral Reef Ecosystem Division, National Oceanic and Atmospheric Administration (NOAA), Honolulu, HI 96822, USA
| | - B. Zgliczynski
- Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0202, USA
| | - S. A. Sandin
- Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0202, USA
| | - J. E. Smith
- Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0202, USA
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67
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Sheehan EV, Stevens TF, Gall SC, Cousens SL, Attrill MJ. Recovery of a temperate reef assemblage in a marine protected area following the exclusion of towed demersal fishing. PLoS One 2013; 8:e83883. [PMID: 24391841 PMCID: PMC3877100 DOI: 10.1371/journal.pone.0083883] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 11/14/2013] [Indexed: 11/30/2022] Open
Abstract
Marine Protected Areas MPA have been widely used over the last 2 decades to address human impacts on marine habitats within an ecosystem management context. Few studies have quantified recovery of temperate rocky reef communities following the cessation of scallop dredging or demersal trawling. This is critical information for the future management of these habitats to contribute towards conservation and fisheries targets. The Lyme Bay MPA, in south west UK, has excluded towed demersal fishing gear from 206 km2 of sensitive reef habitat using a Statutory Instrument since July 2008. To assess benthic recovery in this MPA we used a flying video array to survey macro epi-benthos annually from 2008 to 2011. 4 treatments (the New Closure, previously voluntarily Closed Controls and Near or Far Open to fishing Controls) were sampled to test a recovery hypothesis that was defined as ‘the New Closure becoming more similar to the Closed Controls and less similar to the Open Controls’. Following the cessation of towed demersal fishing, within three years positive responses were observed for species richness, total abundance, assemblage composition and seven of 13 indicator taxa. Definitive evidence of recovery was noted for species richness and three of the indicator taxa (Pentapora fascialis, Phallusia mammillata and Pecten maximus). While it is hoped that MPAs, which exclude anthropogenic disturbance, will allow functional restoration of goods and services provided by benthic communities, it is an unknown for temperate reef systems. Establishing the likely timescales for restoration is key to future marine management. We demonstrate the early stages of successful recruitment and link these to the potential wider ecosystem benefits including those to commercial fisheries.
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Affiliation(s)
- Emma V. Sheehan
- Marine Institute, Plymouth University, Drake Circus, Plymouth, United Kingdom
- * E-mail:
| | - Timothy F. Stevens
- Griffith School of Environment and Australian Rivers Institute - Coasts and Estuaries, Griffith University, Gold Coast, Queensland, Australia
| | - Sarah C. Gall
- Marine Institute, Plymouth University, Drake Circus, Plymouth, United Kingdom
| | - Sophie L. Cousens
- Marine Institute, Plymouth University, Drake Circus, Plymouth, United Kingdom
| | - Martin J. Attrill
- Marine Institute, Plymouth University, Drake Circus, Plymouth, United Kingdom
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68
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García-Rubies A, Hereu B, Zabala M. Long-term recovery patterns and limited spillover of large predatory fish in a Mediterranean MPA. PLoS One 2013; 8:e73922. [PMID: 24069251 PMCID: PMC3771876 DOI: 10.1371/journal.pone.0073922] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 07/25/2013] [Indexed: 11/19/2022] Open
Abstract
Based on 19 y of visual census data from the Medes Islands MPA (NW Mediterranean), this study analyzes the carrying capacity (K) and population recovery time of six species of fish strongly affected by harvesting pressure along the Mediterranean coast. Three of these species (Epinephelus marginatus, Diplodus cervinus and Dicentrachus labrax) have practically reached carrying capacity in the Medes Islands MPA, while others are still approaching population stabilization (Sciaena umbra) or are still increasing in biomass (Dentex dentex). The one exception to these trends is S. aurata, which tended to decrease inside the MPA, probably due to fishing just outside its borders. These results confirm that fish populations may require decadal time scales to recover from exploitation, both in terms of total abundance (21 to 29 y to exceed 95% K) as well as total biomass (25 to 35 y), and that rates of recovery differ between species (13 to 31 y). The recovery and saturation observed within the no-take zone contrasts with results obtained in the partially protected buffer area and the peripheral area open for fishing, which show much lower biomass values. In general, the spillover from the MPA is very moderate, and its effects extend only to the partially protected area.
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Affiliation(s)
| | - Bernat Hereu
- Departament d’Ecologia, Universitat de Barcelona, Barcelona, Spain
| | - Mikel Zabala
- Departament d’Ecologia, Universitat de Barcelona, Barcelona, Spain
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69
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Cinner JE, Graham NAJ, Huchery C, Macneil MA. Global effects of local human population density and distance to markets on the condition of coral reef fisheries. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2013; 27:453-8. [PMID: 23025334 DOI: 10.1111/j.1523-1739.2012.01933.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 06/09/2012] [Indexed: 05/23/2023]
Abstract
Coral reef fisheries support the livelihoods of millions of people but have been severely and negatively affected by anthropogenic activities. We conducted a systematic review of published data on the biomass of coral reef fishes to explore how the condition of reef fisheries is related to the density of local human populations, proximity of the reef to markets, and key environmental variables (including broad geomorphologic reef type, reef area, and net productivity). When only population density and environmental covariates were considered, high variability in fisheries conditions at low human population densities resulted in relatively weak explanatory models. The presence or absence of human settlements, habitat type, and distance to fish markets provided a much stronger explanatory model for the condition of reef fisheries. Fish biomass remained relatively low within 14 km of markets, then biomass increased exponentially as distance from reefs to markets increased. Our results suggest the need for an increased science and policy focus on markets as both a key driver of the condition of reef fisheries and a potential source of solutions.
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Affiliation(s)
- Joshua E Cinner
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia.
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70
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71
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Rife AN, Aburto-Oropeza O, Hastings PA, Erisman B, Ballantyne F, Wielgus J, Sala E, Gerber L. Long-term effectiveness of a multi-use marine protected area on reef fish assemblages and fisheries landings. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2013; 117:276-283. [PMID: 23416447 DOI: 10.1016/j.jenvman.2012.12.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Revised: 12/19/2012] [Accepted: 12/24/2012] [Indexed: 06/01/2023]
Abstract
The Loreto Bay National Park (LBNP) is a large, multi-use marine protected area in the Gulf of California, Mexico, where several types of small-scale commercial and recreational fishing are allowed, but where less than 1% of the park is totally protected from fishing. The LBNP was created in 1996; its management plan was completed in 2000, but it was not effectively implemented and enforced until 2003. Between 1998 and 2010, we monitored reef fish populations annually at several reefs inside and outside the LBNP to measure the effects of the park on fish assemblages. We also evaluated reported fisheries landings within the LBNP for the same time series. Our results show that reef fish biomass increased significantly after protection at a small no-take site at LBNP relative to the rest of the park. However, the multi-use part of LBNP where fishing is allowed (99% of its surface) has had no measurable effect on reef fish biomass relative to open access sites outside the park boundaries. Reported fisheries landings have decreased within the park while increasing in nearby unprotected areas. Although the current partial protection management regime has not allowed for reef fish populations to recover despite 15 years as a "protected area," we conclude that LBNP's regulations and management have maintained the conditions of the ecosystem that existed when the park was established. These results suggest that community livelihoods have been sustained, but a re-evaluation of the multi-use management strategy, particularly the creation of larger no-take zones and better enforcement, is needed to improve the reef fish populations in the park in order to ensure sustainable fisheries far into the future. These recommendations can be applied to all multi-use MPAs in Mexico where ecosystem recovery is not occurring despite maintenance of fish stocks.
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Affiliation(s)
- Alexis N Rife
- Center for Marine Biodiversity and Conservation, Marine Biology Research Division, Scripps Institution of Oceanography, La Jolla, CA 92093-0202, USA.
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72
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Noble MM, van Laake G, Berumen ML, Fulton CJ. Community change within a Caribbean coral reef Marine Protected Area following two decades of local management. PLoS One 2013; 8:e54069. [PMID: 23342078 PMCID: PMC3544719 DOI: 10.1371/journal.pone.0054069] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 12/10/2012] [Indexed: 12/04/2022] Open
Abstract
Structural change in both the habitat and reef-associated fish assemblages within spatially managed coral reefs can provide key insights into the benefits and limitations of Marine Protected Areas (MPAs). While MPA zoning effects on particular target species are well reported, we are yet to fully resolve the various affects of spatial management on the structure of coral reef communities over decadal time scales. Here, we document mixed affects of MPA zoning on fish density, biomass and species richness over the 21 years since establishment of the Saba Marine Park (SMP). Although we found significantly greater biomass and species richness of reef-associated fishes within shallow habitats (5 meters depth) closed to fishing, this did not hold for deeper (15 m) habitats, and there was a widespread decline (38% decrease) in live hard coral cover and a 68% loss of carnivorous reef fishes across all zones of the SMP from the 1990s to 2008. Given the importance of live coral for the maintenance and replenishment of reef fishes, and the likely role of chronic disturbance in driving coral decline across the region, we explore how local spatial management can help protect coral reef ecosystems within the context of large-scale environmental pressures and disturbances outside the purview of local MPA management.
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Affiliation(s)
- Mae M Noble
- ARC Centre of Excellence for Coral Reef Studies, Research School of Biology, The Australian National University, Canberra, Australia.
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73
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The Status of Coral Reef Fish Assemblages in the Chagos Archipelago, with Implications for Protected Area Management and Climate Change. CORAL REEFS OF THE WORLD 2013. [DOI: 10.1007/978-94-007-5965-7_19] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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74
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Rife AN, Erisman B, Sanchez A, Aburto-Oropeza O. When good intentions are not enough … Insights on networks of “paper park” marine protected areas. Conserv Lett 2012. [DOI: 10.1111/j.1755-263x.2012.00303.x] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Affiliation(s)
- Alexis N. Rife
- Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography; University of California San Diego; La Jolla; CA; USA
| | - Brad Erisman
- Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography; University of California San Diego; La Jolla; CA; USA
| | - Alexandra Sanchez
- Centro para la Biodiversidad Marina y la Conservación; La Paz; Baja California Sur; Mexico
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75
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Tkachenko KS. The northernmost coral frontier of the Maldives: The coral reefs of Ihavandippolu Atoll under long-term environmental change. MARINE ENVIRONMENTAL RESEARCH 2012; 82:40-48. [PMID: 23063708 DOI: 10.1016/j.marenvres.2012.09.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 09/14/2012] [Accepted: 09/17/2012] [Indexed: 06/01/2023]
Abstract
Ihavandippolu, the northernmost atoll of the Maldives, experienced severe coral bleaching and mortality in 1998 followed by several bleaching episodes in the last decade. Coral cover in the 11 study sites surveyed in July-December of 2011 in the 3-5 m depth range varied from 1.7 to 51%. Reefs of the islands located in the center of Ihavandippolu lagoon have exhibited a very low coral recovery since 1998 and remain mostly degraded 12 years after the impact. At the same time, some reefs, especially in the inner part of the eastern ring of the atoll, demonstrate a high coral cover (>40%) with a dominance of branching Acropora that is known to be one of the coral genera that is most susceptible to thermal stress. The last severe bleaching event in 2010 resulted in high coral mortality in some sites of the atoll. Differences in coral mortality rates and proportion between "susceptible" and "resistant" taxa in study sites are apparently related to long-term adaptation and local hydrological features that can mitigate thermal impacts. Abundant herbivorous fish observed in the atoll prevent coral overgrowth by macroalgae even on degraded reefs. Despite the frequent influence of temperature anomalies and having less geomorphologic refuges for coral survivals than other larger Maldivian atolls, a major part of observed coral communities in Ihavandippolu Atoll exhibits high resilience and potential for further acclimatization to a changing environment.
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76
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Weak compliance undermines the success of no-take zones in a large government-controlled marine protected area. PLoS One 2012; 7:e50074. [PMID: 23226237 PMCID: PMC3511441 DOI: 10.1371/journal.pone.0050074] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 10/16/2012] [Indexed: 11/19/2022] Open
Abstract
The effectiveness of marine protected areas depends largely on whether people comply with the rules. We quantified temporal changes in benthic composition, reef fish biomass, and fishing effort among marine park zones (including no-take areas) to assess levels of compliance following the 2005 rezoning of the government-controlled Karimunjawa National Park (KNP), Indonesia. Four years after the rezoning awareness of fishing regulations was high amongst local fishers, ranging from 79.5±7.9 (SE) % for spatial restrictions to 97.7±1.2% for bans on the use of poisons. Despite this high awareness and strong compliance with gear restrictions, compliance with spatial restrictions was weak. In the four years following the rezoning reef fish biomass declined across all zones within KNP, with >50% reduction within the no-take Core and Protection Zones. These declines were primarily driven by decreases in the biomass of groups targeted by local fishers; planktivores, herbivores, piscivores, and invertivores. These declines in fish biomass were not driven by changes in habitat quality; coral cover increased in all zones, possibly as a result of a shift in fishing gears from those which can damage reefs (i.e., nets) to those which cause little direct damage (i.e., handlines and spears). Direct observations of fishing activities in 2009 revealed there was limited variation in fishing effort between zones in which fishing was allowed or prohibited. The apparent willingness of the KNP communities to comply with gear restrictions, but not spatial restrictions is difficult to explain and highlights the complexities of the social and economic dynamics that influence the ecological success of marine protected areas. Clearly the increased and high awareness of fishery restrictions following the rezoning is a positive step. The challenge now is to understand and foster the conditions that may facilitate compliance with spatial restrictions within KNP and marine parks worldwide.
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77
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Januchowski-Hartley FA, Graham NAJ, Cinner JE, Russ GR. Spillover of fish naïveté from marine reserves. Ecol Lett 2012; 16:191-7. [PMID: 23126388 DOI: 10.1111/ele.12028] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 08/09/2012] [Accepted: 10/09/2012] [Indexed: 11/28/2022]
Abstract
Spillover of adult fish biomass is an expected benefit from no-take marine reserves to adjacent fisheries. Here, we show fisher-naïve behaviour in reef fishes also spills over from marine reserves, potentially increasing access to fishery benefits by making fishes more susceptible to spearguns. The distance at which two targeted families of fishes began to flee a potential fisher [flight initiation distance (FID)] was lower inside reserves than in fished areas, and this reduction extended outside reserve boundaries. Reduced FID persisted further outside reserves than increases in fish biomass. This finding could help increase stakeholder support for marine reserves and improve current models of spillover by informing estimates for spatial changes in catchability. Behavioural changes of fish could help explain differences between underwater visual census and catch data in quantifying the spatial extent of spillover from marine reserves, and should be considered in the management of adjacent fisheries.
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Affiliation(s)
- Fraser A Januchowski-Hartley
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, 4811, Australia.
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78
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Exploring the effects of spatial closures in a temperate marine ecosystem in Western Australia: A case study of the western rock lobster (Panulirus cygnus) fishery. Ecol Modell 2012. [DOI: 10.1016/j.ecolmodel.2012.05.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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79
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Berumen ML, Almany GR, Planes S, Jones GP, Saenz-Agudelo P, Thorrold SR. Persistence of self-recruitment and patterns of larval connectivity in a marine protected area network. Ecol Evol 2012; 2:444-52. [PMID: 22423335 PMCID: PMC3298954 DOI: 10.1002/ece3.208] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 12/28/2011] [Indexed: 11/25/2022] Open
Abstract
The use of marine protected area (MPA) networks to sustain fisheries and conserve biodiversity is predicated on two critical yet rarely tested assumptions. Individual MPAs must produce sufficient larvae that settle within that reserve's boundaries to maintain local populations while simultaneously supplying larvae to other MPA nodes in the network that might otherwise suffer local extinction. Here, we use genetic parentage analysis to demonstrate that patterns of self-recruitment of two reef fishes (Amphiprion percula and Chaetodon vagabundus) in an MPA in Kimbe Bay, Papua New Guinea, were remarkably consistent over several years. However, dispersal from this reserve to two other nodes in an MPA network varied between species and through time. The stability of our estimates of self-recruitment suggests that even small MPAs may be self-sustaining. However, our results caution against applying optimization strategies to MPA network design without accounting for variable connectivity among species and over time.
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80
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Comeros-Raynal MT, Choat JH, Polidoro BA, Clements KD, Abesamis R, Craig MT, Lazuardi ME, McIlwain J, Muljadi A, Myers RF, Nañola CL, Pardede S, Rocha LA, Russell B, Sanciangco JC, Stockwell B, Harwell H, Carpenter KE. The likelihood of extinction of iconic and dominant herbivores and detritivores of coral reefs: the parrotfishes and surgeonfishes. PLoS One 2012; 7:e39825. [PMID: 22808066 PMCID: PMC3394754 DOI: 10.1371/journal.pone.0039825] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 05/27/2012] [Indexed: 11/18/2022] Open
Abstract
Parrotfishes and surgeonfishes perform important functional roles in the dynamics of coral reef systems. This is a consequence of their varied feeding behaviors ranging from targeted consumption of living plant material (primarily surgeonfishes) to feeding on detrital aggregates that are either scraped from the reef surface or excavated from the deeper reef substratum (primarily parrotfishes). Increased fishing pressure and widespread habitat destruction have led to population declines for several species of these two groups. Species-specific data on global distribution, population status, life history characteristics, and major threats were compiled for each of the 179 known species of parrotfishes and surgeonfishes to determine the likelihood of extinction of each species under the Categories and Criteria of the IUCN Red List of Threatened Species. Due in part to the extensive distributions of most species and the life history traits exhibited in these two families, only three (1.7%) of the species are listed at an elevated risk of global extinction. The majority of the parrotfishes and surgeonfishes (86%) are listed as Least Concern, 10% are listed as Data Deficient and 1% are listed as Near Threatened. The risk of localized extinction, however, is higher in some areas, particularly in the Coral Triangle region. The relatively low proportion of species globally listed in threatened Categories is highly encouraging, and some conservation successes are attributed to concentrated conservation efforts. However, with the growing realization of man's profound impact on the planet, conservation actions such as improved marine reserve networks, more stringent fishing regulations, and continued monitoring of the population status at the species and community levels are imperative for the prevention of species loss in these groups of important and iconic coral reef fishes.
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Affiliation(s)
- Mia T Comeros-Raynal
- IUCN Species Programme/SSC Marine Biodiversity Unit-Global Marine Species Assessment, Biological Sciences, Old Dominion University, Norfolk, Virginia, United States of America.
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81
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Taylor BM, McIlwain JL, Kerr AM. Marine reserves and reproductive biomass: a case study of a heavily targeted reef fish. PLoS One 2012; 7:e39599. [PMID: 22761836 PMCID: PMC3383677 DOI: 10.1371/journal.pone.0039599] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 05/28/2012] [Indexed: 11/18/2022] Open
Abstract
Recruitment overfishing (the reduction of a spawning stock past a point at which the stock can no longer replenish itself) is a common problem which can lead to a rapid and irreversible fishery collapse. Averting this disaster requires maintaining a sufficient spawning population to buffer stochastic fluctuations in recruitment of heavily harvested stocks. Optimal strategies for managing spawner biomass are well developed for temperate systems, yet remain uncertain for tropical fisheries, where the danger of collapse from recruitment overfishing looms largest. In this study, we explored empirically and through modeling, the role of marine reserves in maximizing spawner biomass of a heavily exploited reef fish, Lethrinus harak around Guam, Micronesia. On average, spawner biomass was 16 times higher inside the reserves compared with adjacent fished sites. Adult density and habitat-specific mean fish size were also significantly greater. We used these data in an age-structured population model to explore the effect of several management scenarios on L. harak demography. Under minimum-size limits, unlimited extraction and all rotational-closure scenarios, the model predicts that preferential mortality of larger and older fish prompt dramatic declines in spawner biomass and the proportion of male fish, as well as considerable declines in total abundance. For rotational closures this occurred because of the mismatch between the scales of recovery and extraction. Our results highlight how alternative management scenarios fall short in comparison to marine reserves in preserving reproductively viable fish populations on coral reefs.
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Affiliation(s)
- Brett M Taylor
- Marine Laboratory, University of Guam, Mangilao, Guam, United States of America.
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82
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Takashina N, Mougi A, Iwasa Y. Paradox of marine protected areas: suppression of fishing may cause species loss. POPUL ECOL 2012. [DOI: 10.1007/s10144-012-0323-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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83
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Ward-Paige CA, Keith DM, Worm B, Lotze HK. Recovery potential and conservation options for elasmobranchs. JOURNAL OF FISH BIOLOGY 2012; 80:1844-69. [PMID: 22497409 DOI: 10.1111/j.1095-8649.2012.03246.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Many elasmobranchs have experienced strong population declines, which have been largely attributed to the direct and indirect effects of exploitation. Recently, however, live elasmobranchs are being increasingly valued for their role in marine ecosystems, dive tourism and intrinsic worth. Thus, management plans have been implemented to slow and ultimately reverse negative trends, including shark-specific (e.g. anti-finning laws) to ecosystem-based (e.g. no-take marine reserves) strategies. Yet it is unclear how successful these measures are, or will be, given the degree of depletion and slow recovery potential of most elasmobranchs. Here, current understanding of elasmobranch population recoveries is reviewed. The potential and realized extent of population increases, including rates of increase, timelines and drivers are evaluated. Across 40 increasing populations, only 25% were attributed to decreased anthropogenic mortality, while the majority was attributed to predation release. It is also shown that even low exploitation rates (2-6% per year) can halt or reverse positive population trends in six populations currently managed under recovery plans. Management measures that help restore elasmobranch populations include enforcement or near-zero fishing mortality, protection of critical habitats, monitoring and education. These measures are highlighted in a case study from the south-eastern U.S.A., where some evidence of recovery is seen in Pristis pectinata, Galeocerdo cuvier and Sphyrna lewini populations. It is concluded that recovery of elasmobranchs is certainly possible but requires time and a combination of strong and dedicated management actions to be successful.
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Affiliation(s)
- C A Ward-Paige
- Department of Biology, Dalhousie University, Halifax NS, B3H 4R2, Canada.
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84
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Sala E, Ballesteros E, Dendrinos P, Di Franco A, Ferretti F, Foley D, Fraschetti S, Friedlander A, Garrabou J, Güçlüsoy H, Guidetti P, Halpern BS, Hereu B, Karamanlidis AA, Kizilkaya Z, Macpherson E, Mangialajo L, Mariani S, Micheli F, Pais A, Riser K, Rosenberg AA, Sales M, Selkoe KA, Starr R, Tomas F, Zabala M. The structure of Mediterranean rocky reef ecosystems across environmental and human gradients, and conservation implications. PLoS One 2012; 7:e32742. [PMID: 22393445 PMCID: PMC3290621 DOI: 10.1371/journal.pone.0032742] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 01/30/2012] [Indexed: 11/18/2022] Open
Abstract
Historical exploitation of the Mediterranean Sea and the absence of rigorous baselines makes it difficult to evaluate the current health of the marine ecosystems and the efficacy of conservation actions at the ecosystem level. Here we establish the first current baseline and gradient of ecosystem structure of nearshore rocky reefs at the Mediterranean scale. We conducted underwater surveys in 14 marine protected areas and 18 open access sites across the Mediterranean, and across a 31-fold range of fish biomass (from 3.8 to 118 g m(-2)). Our data showed remarkable variation in the structure of rocky reef ecosystems. Multivariate analysis showed three alternative community states: (1) large fish biomass and reefs dominated by non-canopy algae, (2) lower fish biomass but abundant native algal canopies and suspension feeders, and (3) low fish biomass and extensive barrens, with areas covered by turf algae. Our results suggest that the healthiest shallow rocky reef ecosystems in the Mediterranean have both large fish and algal biomass. Protection level and primary production were the only variables significantly correlated to community biomass structure. Fish biomass was significantly larger in well-enforced no-take marine reserves, but there were no significant differences between multi-use marine protected areas (which allow some fishing) and open access areas at the regional scale. The gradients reported here represent a trajectory of degradation that can be used to assess the health of any similar habitat in the Mediterranean, and to evaluate the efficacy of marine protected areas.
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Affiliation(s)
- Enric Sala
- National Geographic Society, Washington, DC, United States of America.
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85
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Allnutt TF, McClanahan TR, Andréfouët S, Baker M, Lagabrielle E, McClennen C, Rakotomanjaka AJM, Tianarisoa TF, Watson R, Kremen C. Comparison of marine spatial planning methods in Madagascar demonstrates value of alternative approaches. PLoS One 2012; 7:e28969. [PMID: 22359534 PMCID: PMC3281012 DOI: 10.1371/journal.pone.0028969] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 11/18/2011] [Indexed: 11/25/2022] Open
Abstract
The Government of Madagascar plans to increase marine protected area coverage by over one million hectares. To assist this process, we compare four methods for marine spatial planning of Madagascar's west coast. Input data for each method was drawn from the same variables: fishing pressure, exposure to climate change, and biodiversity (habitats, species distributions, biological richness, and biodiversity value). The first method compares visual color classifications of primary variables, the second uses binary combinations of these variables to produce a categorical classification of management actions, the third is a target-based optimization using Marxan, and the fourth is conservation ranking with Zonation. We present results from each method, and compare the latter three approaches for spatial coverage, biodiversity representation, fishing cost and persistence probability. All results included large areas in the north, central, and southern parts of western Madagascar. Achieving 30% representation targets with Marxan required twice the fish catch loss than the categorical method. The categorical classification and Zonation do not consider targets for conservation features. However, when we reduced Marxan targets to 16.3%, matching the representation level of the “strict protection” class of the categorical result, the methods show similar catch losses. The management category portfolio has complete coverage, and presents several management recommendations including strict protection. Zonation produces rapid conservation rankings across large, diverse datasets. Marxan is useful for identifying strict protected areas that meet representation targets, and minimize exposure probabilities for conservation features at low economic cost. We show that methods based on Zonation and a simple combination of variables can produce results comparable to Marxan for species representation and catch losses, demonstrating the value of comparing alternative approaches during initial stages of the planning process. Choosing an appropriate approach ultimately depends on scientific and political factors including representation targets, likelihood of adoption, and persistence goals.
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Affiliation(s)
- Thomas F Allnutt
- Department of Environmental Science, Policy and Management, University of California, Berkeley, Berkeley, California, United States of America.
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86
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Żychaluk K, Bruno JF, Clancy D, McClanahan TR, Spencer M. Data-driven models for regional coral-reef dynamics. Ecol Lett 2011; 15:151-8. [DOI: 10.1111/j.1461-0248.2011.01720.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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87
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McClanahan TR, Omukoto JO. Comparison of modern and historical fish catches (AD 750-1400) to inform goals for marine protected areas and sustainable fisheries. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2011; 25:945-955. [PMID: 21676028 DOI: 10.1111/j.1523-1739.2011.01694.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We tested the unsustainable fishing hypothesis that species in assemblages of fish differ in relative abundance as a function of their size, growth rates, vagility, trophic level, and diet by comparing species composition in historical bone middens, modern fisheries, and areas closed to fishing. Historical data came from one of the earliest and most enduring Swahili coastal settlements (approximately AD 750-1400). Modern data came from fisheries near the archeological site and intensively harvested fishing grounds in southern Kenya. The areas we sampled that were closed to fishing (closures) were small (<28 km(2) ) and permanent. The midden data indicated changes in the fish assemblage that are consistent with a weak expansion of fishing intensity and the unsustainable fishing hypothesis. Fishes represented in the early midden assemblages from AD 750 to 950 had longer life spans, older age at maturity, and longer generation times than fish assemblages after AD 950, when the abundance of species with longer maximum body lengths increased. Changes in fish life histories during the historical period were, however, one-third smaller than differences between the historical and modern assemblages. Fishes in the modern assemblage had smaller mean body sizes, higher growth and mortality rates, a higher proportion of microinvertivores, omnivores, and herbivores, and higher rates of food consumption, whereas the historical assemblage had a greater proportion of piscivores and macroinvertivores. Differences in fish life histories between modern closures and modern fishing grounds were also small, but the life histories of fishes in modern closures were more similar to those in the midden before AD 950 because they had longer life spans, older age at maturity, and a higher proportion of piscivores and macroinvertivores than the modern fisheries. Modern closures and historical fish assemblages were considerably different, although both contained species with longer life spans.
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88
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Lotze HK, Coll M, Magera AM, Ward-Paige C, Airoldi L. Recovery of marine animal populations and ecosystems. Trends Ecol Evol 2011; 26:595-605. [PMID: 21852017 DOI: 10.1016/j.tree.2011.07.008] [Citation(s) in RCA: 134] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 07/14/2011] [Accepted: 07/15/2011] [Indexed: 11/19/2022]
Abstract
Many marine populations and ecosystems have experienced strong historical depletions, yet reports of recoveries are increasing. Here, we review the growing research on marine recoveries to reveal how common recovery is, its magnitude, timescale and major drivers. Overall, 10-50% of depleted populations and ecosystems show some recovery, but rarely to former levels of abundance. In addition, recovery can take many decades for long-lived species and complex ecosystems. Major drivers of recovery include the reduction of human impacts, especially exploitation, habitat loss and pollution, combined with favorable life-history and environmental conditions. Awareness, legal protection and enforcement of management plans are also crucial. Learning from historical recovery successes and failures is essential for implementing realistic conservation goals and promising management strategies.
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Affiliation(s)
- Heike K Lotze
- Biology Department, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
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89
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Aburto-Oropeza O, Erisman B, Galland GR, Mascareñas-Osorio I, Sala E, Ezcurra E. Large recovery of fish biomass in a no-take marine reserve. PLoS One 2011; 6:e23601. [PMID: 21858183 PMCID: PMC3155316 DOI: 10.1371/journal.pone.0023601] [Citation(s) in RCA: 144] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 07/20/2011] [Indexed: 11/30/2022] Open
Abstract
No-take marine reserves are effective management tools used to restore fish biomass and community structure in areas depleted by overfishing. Cabo Pulmo National Park (CPNP) was created in 1995 and is the only well enforced no-take area in the Gulf of California, Mexico, mostly because of widespread support from the local community. In 1999, four years after the establishment of the reserve, there were no significant differences in fish biomass between CPNP (0.75 t ha−1 on average) and other marine protected areas or open access areas in the Gulf of California. By 2009, total fish biomass at CPNP had increased to 4.24 t ha−1 (absolute biomass increase of 3.49 t ha−1, or 463%), and the biomass of top predators and carnivores increased by 11 and 4 times, respectively. However, fish biomass did not change significantly in other marine protected areas or open access areas over the same time period. The absolute increase in fish biomass at CPNP within a decade is the largest measured in a marine reserve worldwide, and it is likely due to a combination of social (strong community leadership, social cohesion, effective enforcement) and ecological factors. The recovery of fish biomass inside CPNP has resulted in significant economic benefits, indicating that community-managed marine reserves are a viable solution to unsustainable coastal development and fisheries collapse in the Gulf of California and elsewhere.
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Affiliation(s)
- Octavio Aburto-Oropeza
- Marine Biology Research Division, Scripps Institution of Oceanography, La Jolla, California, United States of America.
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90
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Feary DA, Cinner JE, Graham NAJ, Januchowski-Hartley FA. Effects of customary marine closures on fish behavior, spear-fishing success, and underwater visual surveys. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2011; 25:341-349. [PMID: 21129032 DOI: 10.1111/j.1523-1739.2010.01613.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Customary management systems (i.e., management systems that limit the use of marine resources), such as rotational fisheries closures, can limit harvest of resources. Nevertheless, the explicit goals of customary management are often to influence fish behavior (in particular flight distance, i.e., distance at which an organism begins to flee an approaching threat), rather than fish abundance. We explored whether the flight distance of reef fishes targeted by local artisanal fishers differed between a customary closure and fished reefs. We also examined whether flight distance of these species affected fishing success and accuracy of underwater visual census (UVC) between customary closed areas and areas open to fishing. Several species demonstrated significant differences in flight distance between areas, indicating that fishing activity may increase flight distance. These relatively long flight distances mean that in fished areas most target species may stay out of the range of spear fishers. In addition, mean flight distances for all species both inside and outside the customary-closure area were substantially smaller than the observation distance of an observer conducting a belt-transect UVC (mean [SE]= 8.8 m [0.48]). For targeted species that showed little ability to evade spear fishers, customary closures may be a vital management technique. Our results show that customary closures can have a substantial, positive effect on resource availability and that conventional UVC techniques may be insensitive to changes in flight behavior of fishes associated with fishing. We argue that short, periodic openings of customary closures may allow the health of the fish community to be maintained and local fishers to effectively harvest fishes.
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Affiliation(s)
- David A Feary
- United Nations University, Institute for Water, Environment and Health, Hamilton, ON L8P 0A1, Canada.
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91
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Graham NAJ, Chabanet P, Evans RD, Jennings S, Letourneur Y, Aaron Macneil M, McClanahan TR, Ohman MC, Polunin NVC, Wilson SK. Extinction vulnerability of coral reef fishes. Ecol Lett 2011; 14:341-8. [PMID: 21320260 PMCID: PMC3627313 DOI: 10.1111/j.1461-0248.2011.01592.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
With rapidly increasing rates of contemporary extinction, predicting extinction vulnerability and identifying how multiple stressors drive non-random species loss have become key challenges in ecology. These assessments are crucial for avoiding the loss of key functional groups that sustain ecosystem processes and services. We developed a novel predictive framework of species extinction vulnerability and applied it to coral reef fishes. Although relatively few coral reef fishes are at risk of global extinction from climate disturbances, a negative convex relationship between fish species locally vulnerable to climate change vs. fisheries exploitation indicates that the entire community is vulnerable on the many reefs where both stressors co-occur. Fishes involved in maintaining key ecosystem functions are more at risk from fishing than climate disturbances. This finding is encouraging as local and regional commitment to fisheries management action can maintain reef ecosystem functions pending progress towards the more complex global problem of stabilizing the climate.
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Affiliation(s)
- Nicholas A J Graham
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Qld 4811, Australia.
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92
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Claudet J, García-Charton JA, Lenfant P. Combined effects of levels of protection and environmental variables at different spatial resolutions on fish assemblages in a marine protected area. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2011; 25:105-114. [PMID: 20961331 DOI: 10.1111/j.1523-1739.2010.01586.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The links between species-environment relations and species' responses to protection are unclear, but the objectives of marine protected areas (MPAs) are most likely to be achieved when those relations are known and inform MPA design. The components of a species' habitat vary with the spatial resolution of the area considered. We characterized areas at two resolutions: 250 m(2) (transect) and approximately 30,000 m(2) (seascape). We considered three categories of environmental variables: substrate type, bottom complexity, and depth. We sought to determine at which resolution habitat characteristics were a better predictor of abundance and species composition of fishes and whether the relations with environmental variables at either resolution affected species' responses to protection. Habitat features accounted for a larger proportion of spatial variation in species composition and abundances than differences in protection status. This spatial variation was explained best by habitat characteristics at the seascape level than at the transect level. Species' responses to protected areas were specific to particular seascape characteristics, primarily depth, and bottom complexity. Our method may be useful for prioritizing marine areas for protection, designing MPAs, and monitoring their effectiveness. It identified areas that provided natural shelter, areas acting as buffer zones, and areas where fish species were most responsive to protection. The identification of such areas is necessary for cost-effective establishment and monitoring of MPAs.
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Affiliation(s)
- Joachim Claudet
- Laboratory of Marine Biology and Zoology, DiSTeBA, University of Salento, Lecce, Italy.
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93
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O'Leary JK, McClanahan TR. Trophic cascades result in large‐scale coralline algae loss through differential grazer effects. Ecology 2010; 91:3584-97. [PMID: 21302830 DOI: 10.1890/09-2059.1] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Jennifer K. O'Leary
- University of California, Santa Cruz, 100 Schaffer Road, Santa Cruz, California 95060 USA
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94
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McClanahan TR. Effects of fisheries closures and gear restrictions on fishing income in a Kenyan coral reef. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2010; 24:1519-28. [PMID: 20497202 DOI: 10.1111/j.1523-1739.2010.01530.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The adoption of fisheries closures and gear restrictions in the conservation of coral reefs may be limited by poor understanding of the economic profitability of competing economic uses of marine resources. Over the past 12 years, I evaluated the effects of gear regulation and fisheries closures on per person and per area incomes from fishing in coral reefs of Kenya. In two of my study areas, the use of small-meshed beach seines was stopped after 6 years; one of these areas was next to a fishery closure. In my third study area, fishing was unregulated. Fishing yields on per capita daily wet weight basis were 20% higher after seine-net fishing was stopped. The per person daily fishing income adjacent to the closed areas was 14 and 22% higher than the fishing income at areas with only gear restrictions before and after the seine-net restriction, respectively. Incomes differed because larger fish were captured next to the closed area and the price per weight (kilograms) increased as fish size increased and because catches adjacent to the closure contained fish species of higher market value. Per capita incomes were 41 and 135% higher for those who fished in gear-restricted areas and near-closed areas, respectively, compared with those who fished areas with no restrictions. On a per unit area basis (square kilometers), differences in fishing income among the three areas were not large because fishing effort increased as the number of restrictions decreased. Changes in catch were, however, larger and often in the opposite direction expected from changes in effort alone. For example, effort declined 21% but nominal profits per square kilometer (not accounting for inflation) increased 29% near the area with gear restrictions. Gear restrictions also reduced the cost of fishing and increased the proportion of self-employed fishers.
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Affiliation(s)
- Timothy R McClanahan
- Wildlife Conservation Society, Marine Programs, 2300 Southern Boulevard, Bronx, NY 10460, USA.
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95
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Ward-Paige C, Mills Flemming J, Lotze HK. Overestimating fish counts by non-instantaneous visual censuses: consequences for population and community descriptions. PLoS One 2010; 5:e11722. [PMID: 20661304 PMCID: PMC2908695 DOI: 10.1371/journal.pone.0011722] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 06/18/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Increasingly, underwater visual censuses (UVC) are used to assess fish populations. Several studies have demonstrated the effectiveness of protected areas for increasing fish abundance or provided insight into the natural abundance and structure of reef fish communities in remote areas. Recently, high apex predator densities (>100,000 individuals x km(-2)) and biomasses (>4 tonnes x ha(-1)) have been reported for some remote islands suggesting the occurrence of inverted trophic biomass pyramids. However, few studies have critically evaluated the methods used for sampling conspicuous and highly mobile fish such as sharks. Ideally, UVC are done instantaneously, however, researchers often count animals that enter the survey area after the survey has started, thus performing non-instantaneous UVC. METHODOLOGY/PRINCIPAL FINDINGS We developed a simulation model to evaluate counts obtained by divers deploying non-instantaneous belt-transect and stationary-point-count techniques. We assessed how fish speed and survey procedure (visibility, diver speed, survey time and dimensions) affect observed fish counts. Results indicate that the bias caused by fish speed alone is huge, while survey procedures had varying effects. Because the fastest fishes tend to be the largest, the bias would have significant implications on their biomass contribution. Therefore, caution is needed when describing abundance, biomass, and community structure based on non-instantaneous UVC, especially for highly mobile species such as sharks. CONCLUSIONS/SIGNIFICANCE Based on our results, we urge that published literature state explicitly whether instantaneous counts were made and that survey procedures be accounted for when non-instantaneous counts are used. Using published density and biomass values of communities that include sharks we explore the effect of this bias and suggest that further investigation may be needed to determine pristine shark abundances and the existence of inverted biomass pyramids. Because such studies are used to make important management and conservation decisions, incorrect estimates of animal abundance and biomass have serious and significant implications.
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96
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Anticamara JA, Zeller D, Vincent ACJ. Spatial and temporal variation of abundance, biomass and diversity within marine reserves in the Philippines. DIVERS DISTRIB 2010. [DOI: 10.1111/j.1472-4642.2010.00661.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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97
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Dearden P, Theberge M, Yasué M. Using underwater cameras to assess the effects of snorkeler and SCUBA diver presence on coral reef fish abundance, family richness, and species composition. ENVIRONMENTAL MONITORING AND ASSESSMENT 2010; 163:531-538. [PMID: 19353295 DOI: 10.1007/s10661-009-0855-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Accepted: 03/10/2009] [Indexed: 05/27/2023]
Abstract
The results of underwater visual fish censuses (UVC) could be affected by fish changing their behavior in response to the snorkeler or diver conducting the survey. We used an underwater video camera to assess how fish abundance, family richness, and community composition were affected by the presence of snorkelers (n = 12) and self-contained underwater breathing apparatus (SCUBA) divers (n = 6) on a coral reef in Thailand. The total number of families, abundance of some fish families, and overall species composition showed significant differences before and during snorkeling disturbances. We did not detect significant and consistent changes to these parameters in the presence of a SCUBA diver; however, this could be a result of lower statistical power. We suggest that the use of a stationary video camera may help cross-check data that is collected through UVC to assess the true family composition and document the presence of rare and easily disturbed species.
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Affiliation(s)
- P Dearden
- Marine Protected Areas Research Group (MPARG), Department of Geography, University of Victoria, Victoria, BC, V8W3P5,
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98
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Selig ER, Bruno JF. A global analysis of the effectiveness of marine protected areas in preventing coral loss. PLoS One 2010; 5:e9278. [PMID: 20174644 PMCID: PMC2822846 DOI: 10.1371/journal.pone.0009278] [Citation(s) in RCA: 235] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Accepted: 01/19/2010] [Indexed: 11/18/2022] Open
Abstract
Background A variety of human activities have led to the recent global decline of reef-building corals [1], [2]. The ecological, social, and economic value of coral reefs has made them an international conservation priority [2], [3]. The success of Marine Protected Areas (MPAs) in restoring fish populations [4] has led to optimism that they could also benefit corals by indirectly reducing threats like overfishing, which cause coral degradation and mortality [2], [5]. However, the general efficacy of MPAs in increasing coral reef resilience has never been tested. Methodology/Principal Findings We compiled a global database of 8534 live coral cover surveys from 1969–2006 to compare annual changes in coral cover inside 310 MPAs to unprotected areas. We found that on average, coral cover within MPAs remained constant, while coral cover on unprotected reefs declined. Although the short-term differences between unprotected and protected reefs are modest, they could be significant over the long-term if the effects are temporally consistent. Our results also suggest that older MPAs were generally more effective in preventing coral loss. Initially, coral cover continued to decrease after MPA establishment. Several years later, however, rates of coral cover decline slowed and then stabilized so that further losses stopped. Conclusions/Significance These findings suggest that MPAs can be a useful tool not only for fisheries management, but also for maintaining coral cover. Furthermore, the benefits of MPAs appear to increase with the number of years since MPA establishment. Given the time needed to maximize MPA benefits, there should be increased emphasis on implementing new MPAs and strengthening the enforcement of existing MPAs.
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Affiliation(s)
- Elizabeth R Selig
- Curriculum in Ecology, University of North Carolina, Chapel Hill, North Carolina, United States of America.
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99
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Bartlett CY, Manua C, Cinner J, Sutton S, Jimmy R, South R, Nilsson J, Raina J. Comparison of outcomes of permanently closed and periodically harvested coral reef reserves. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2009; 23:1475-1484. [PMID: 19624531 DOI: 10.1111/j.1523-1739.2009.01293.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In many areas of the developing world, the establishment of permanent marine reserves is inhibited by cultural norms or socioeconomic pressures. Community conserved areas that are periodically harvested are increasingly being implemented as fisheries management tools, but few researchers have empirically compared them with permanently closed reserves. We used a hierarchical control-impact experimental design to compare the abundance and biomass of reef fishes, invertebrates, and substrate composition in periodically harvested and permanent reserves and in openly fished (control sites) of the South Pacific island country of Vanuatu. Fished species had significantly higher biomass in periodically harvested reserves than in adjacent openly fished areas. We did not detect differences in substratum composition between permanent reserves and openly fished areas or between permanent reserves and periodically harvested reserves. Giant clams (tridacnids) and top shells (Trochus niloticus) were vulnerable to periodic harvest, and we suggest that for adequate management of these species, periodically harvested community conservation areas be used in conjunction with other management strategies. Periodic harvest within reserves is an example of adaptive and flexible management that may meet conservation goals and that is suited to the social, economic, and cultural contexts of many coastal communities in the developing world.
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Affiliation(s)
- C Y Bartlett
- School of Earth and Environmental Sciences, James Cook University, Townsville, QLD, 4811 Australia.
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100
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Game ET, Bode M, McDonald-Madden E, Grantham HS, Possingham HP. Dynamic marine protected areas can improve the resilience of coral reef systems. Ecol Lett 2009; 12:1336-46. [DOI: 10.1111/j.1461-0248.2009.01384.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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