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Chen R, Chaparro-Pedraza PC, Xiao S, Jia P, Liu QX, de Roos AM. Marine reserves promote cycles in fish populations on ecological and evolutionary time scales. Proc Natl Acad Sci U S A 2023; 120:e2307529120. [PMID: 37956293 PMCID: PMC10666098 DOI: 10.1073/pnas.2307529120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 10/10/2023] [Indexed: 11/15/2023] Open
Abstract
Marine reserves are considered essential for sustainable fisheries, although their effectiveness compared to traditional fisheries management is debated. The effect of marine reserves is mostly studied on short ecological time scales, whereas fisheries-induced evolution is a well-established consequence of harvesting. Using a size-structured population model for an exploited fish population of which individuals spend their early life stages in a nursery habitat, we show that marine reserves will shift the mode of population regulation from low size-selective survival late in life to low, early-life survival due to strong resource competition. This shift promotes the occurrence of rapid ecological cycles driven by density-dependent recruitment as well as much slower evolutionary cycles driven by selection for the optimal body to leave the nursery grounds, especially with larger marine reserves. The evolutionary changes increase harvesting yields in terms of total biomass but cause disproportionately large decreases in yields of larger, adult fish. Our findings highlight the importance of carefully considering the size of marine reserves and the individual life history of fish when managing eco-evolutionary marine systems to ensure both population persistence as well as stable fisheries yields.
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Affiliation(s)
- Renfei Chen
- School of Life Science, Shanxi Normal University, Taiyuan030000, China
| | | | - Suping Xiao
- School of Mathematics and Computer Science, Shanxi Normal University, Taiyuan030000, China
| | - Pu Jia
- Institute of Ecological Science, School of Life Sciences, South China Normal University, Guangzhou510631, China
| | - Quan-Xing Liu
- School of Mathematical Sciences, Shanghai Jiao Tong University, Shanghai200240, China
| | - André M. de Roos
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, AmsterdamNL-1098 XH, The Netherlands
- The Santa Fe Institute, Santa Fe, NM87501
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2
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Peleg O, Blain CO, Shears NT. Long-term marine protection enhances kelp forest ecosystem stability. Ecol Appl 2023; 33:e2895. [PMID: 37282356 DOI: 10.1002/eap.2895] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 05/17/2023] [Accepted: 05/25/2023] [Indexed: 06/08/2023]
Abstract
Trophic downgrading destabilizes ecosystems and can drive large-scale shifts in ecosystem state. While restoring predatory interactions in marine reserves can reverse anthropogenic-driven shifts, empirical evidence of increased ecosystem stability and persistence in the presence of predators is scant. We compared temporal variation in rocky reef ecosystem state in New Zealand's oldest marine reserve to nearby fished reefs to examine whether protection of predators led to more persistent and stable reef ecosystem states in the marine reserve. Contrasting ecosystem states were found between reserve and fished sites, and this persisted over the 22-year study period. Fished sites were predominantly urchin barrens but occasionally fluctuated to short-lived turfs and mixed algal forests, while reserve sites displayed unidirectional successional trajectories toward stable kelp forests (Ecklonia radiata) taking up to three decades following protection. This provides empirical evidence that long-term protection of predators facilitates kelp forest recovery, resists shifts to denuded alternate states, and enhances kelp forest stability.
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Affiliation(s)
- Ohad Peleg
- Institute of Marine Science, The University of Auckland, Auckland, New Zealand
| | - Caitlin O Blain
- Institute of Marine Science, The University of Auckland, Auckland, New Zealand
| | - Nick T Shears
- Institute of Marine Science, The University of Auckland, Auckland, New Zealand
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3
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Pettersen AK, Marzinelli EM, Steinberg PD, Coleman MA. Impact of marine protected areas on temporal stability of fish species diversity. Conserv Biol 2022; 36:e13815. [PMID: 34342040 DOI: 10.1111/cobi.13815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 07/07/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
Preserving biodiversity over time is a pressing challenge for conservation science. A key goal of marine protected areas (MPAs) is to maintain stability in species composition, via reduced turnover, to support ecosystem function. Yet, this stability is rarely measured directly under different levels of protection. Rather, evaluations of MPA efficacy generally consist of static measures of abundance, species richness, and biomass, and rare measures of turnover are limited to short-term studies involving pairwise (beta diversity) comparisons. Zeta diversity is a recently developed metric of turnover that allows for measurement of compositional similarity across multiple assemblages and thus provides more comprehensive estimates of turnover. We evaluated the effectiveness of MPAs at preserving fish zeta diversity across a network of marine reserves over 10 years in Batemans Marine Park, Australia. Snorkel transect surveys were conducted across multiple replicated and spatially interspersed sites to record fish species occurrence through time. Protection provided by MPAs conferred greater stability in fish species turnover. Marine protected areas had significantly shallower decline in zeta diversity compared with partially protected and unprotected areas. The retention of harvested species was four to six times greater in MPAs compared with partially protected and unprotected areas, and the stabilizing effects of protection were observable within 4 years of park implementation. Conversely, partial protection offered little to no improvement in stability, compared with unprotected areas. These findings support the efficacy of MPAs for preserving temporal fish diversity stability. The implementation of MPAs helps stabilize fish diversity and may, therefore, support biodiversity resilience under ongoing environmental change.
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Affiliation(s)
- Amanda K Pettersen
- Sydney Institute of Marine Science, Mosman, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Ezequiel M Marzinelli
- Sydney Institute of Marine Science, Mosman, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Peter D Steinberg
- Sydney Institute of Marine Science, Mosman, New South Wales, Australia
- Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Melinda A Coleman
- Marine Ecosystem Research, Department of Primary Industries, New South Wales Fisheries, Coffs Harbour, New South Wales, Australia
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales, Australia
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4
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Abstract
In marine ecosystems, fishing often targets predators, which can drive direct and indirect effects on entire food webs. Marine reserves can induce trophic cascades by increasing predator density and body size, thereby increasing predation pressure on populations of herbivores, such as sea urchins. In California's northern Channel Islands, two species of sea urchins are abundant: the red urchin Mesocentrotus franciscanus, which is targeted by an economically valuable fishery, and the virtually unfished purple urchin Strongylocentrotus purpuratus. We hypothesized that urchin populations inside marine reserves would be depressed by higher predation, but that red urchins would be less affected due to fishing outside reserves. Instead, our analyses revealed that purple urchin populations were unaffected by reserves, and red urchin biomass significantly increased in response to protection. Therefore, urchin biomass overall has increased inside reserves, and we found no evidence that giant kelp is positively affected by reserves. Our results reveal the overwhelming direct effect of protecting fished species in marine reserves over indirect effects that are often predicted but seldom clearly documented. Indirect effects due to marine reserves may eventually occur in some cases, but very effective predators, large reserves or extended time periods may be needed to induce them.
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Affiliation(s)
- Katrina D Malakhoff
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA 93106-9010, USA
| | - Robert J Miller
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA 93106-9010, USA
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5
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Payet SD, Lowe JR, Mapstone BD, Pratchett MS, Sinclair-Taylor TH, Taylor BM, Waldie PA, Harrison HB. Comparative demography of commercially important species of coral grouper, Plectropomus leopardus and P. laevis, from Australia's great barrier reef and Coral Sea marine parks. J Fish Biol 2020; 97:1165-1176. [PMID: 32785930 DOI: 10.1111/jfb.14491] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 08/04/2020] [Accepted: 08/08/2020] [Indexed: 06/11/2023]
Abstract
Understanding the spatial and environmental variation in demographic processes of fisheries target species, such as coral grouper (Genus: Plectropomus), is important for establishing effective management and conservation strategies. Herein we compare the demography of Plectropomus leopardus and P. laevis between Australia's Great Barrier Reef Marine Park (GBRMP), which has been subject to sustained and extensive fishing pressure, and the oceanic atolls of Australia's Coral Sea Marine Park (CSMP), where there is very limited fishing for reef fishes. Coral grouper length-at-age data from contemporary and historical otolith collections across 9.4 degrees of latitude showed little difference in lifetime growth between GBRMP and CSMP regions. Plectropomus laevis populations in GBRMP reefs had significantly higher rates of total mortality than populations in the CSMP. Mean maximum lengths and mean maximum ages of P. laevis were also smaller in the GBRMP than in the CSMP, even when considering populations sampled within GBRMP no-take marine reserves (NTMRs). Plectropomus leopardus, individuals were on average smaller on fished reefs than NTMRs in the GBRMP, but all other aspects of demography were broadly similar between regions despite the negligible levels of fishing pressure in the CSMP. Similarities between regions in growth profiles and length-at-age comparisons of P. laevis and P. leopardus suggest that the environmental differences between the CSMP and the GBRMP may not have significant impacts on lifetime growth. Our results show that fishing may have influenced the demography of coral grouper on the GBR, particularly for the slower growing and longer lived species, P. laevis.
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Affiliation(s)
- Samuel D Payet
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
| | - Jake R Lowe
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
| | | | - Morgan S Pratchett
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
| | | | - Brett M Taylor
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, The University of Western Australia (M096), Crawley, Western Australia, Australia
| | - Peter A Waldie
- The Nature Conservancy Asia Pacific Resource Centre, Brisbane, Queensland, Australia
| | - Hugo B Harrison
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
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6
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Harrison HB, Bode M, Williamson DH, Berumen ML, Jones GP. A connectivity portfolio effect stabilizes marine reserve performance. Proc Natl Acad Sci U S A 2020; 117:25595-600. [PMID: 32989139 DOI: 10.1073/pnas.1920580117] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Well-managed and enforced no-take marine reserves generate important larval subsidies to neighboring habitats and thereby contribute to the long-term sustainability of fisheries. However, larval dispersal patterns are variable, which leads to temporal fluctuations in the contribution of a single reserve to the replenishment of local populations. Identifying management strategies that mitigate the uncertainty in larval supply will help ensure the stability of recruitment dynamics and minimize the volatility in fishery catches. Here, we use genetic parentage analysis to show extreme variability in both the dispersal patterns and recruitment contribution of four individual marine reserves across six discrete recruitment cohorts for coral grouper (Plectropomus maculatus) on the Great Barrier Reef. Together, however, the asynchronous contributions from multiple reserves create temporal stability in recruitment via a connectivity portfolio effect. This dampening effect reduces the variability in larval supply from individual reserves by a factor of 1.8, which effectively halves the uncertainty in the recruitment contribution of individual reserves. Thus, not only does the network of four marine reserves generate valuable larval subsidies to neighboring habitats, the aggregate effect of individual reserves mitigates temporal fluctuations in dispersal patterns and the replenishment of local populations. Our results indicate that small networks of marine reserves yield previously unrecognized stabilizing benefits that ensure a consistent larval supply to replenish exploited fish stocks.
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7
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Madin EMP, Madin JS, Harmer AMT, Barrett NS, Booth DJ, Caley MJ, Cheal AJ, Edgar GJ, Emslie MJ, Gaines SD, Sweatman HPA. Latitude and protection affect decadal trends in reef trophic structure over a continental scale. Ecol Evol 2020; 10:6954-6966. [PMID: 32760504 PMCID: PMC7391320 DOI: 10.1002/ece3.6347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 04/17/2020] [Indexed: 01/02/2023] Open
Abstract
The relative roles of top-down (consumer-driven) and bottom-up (resource-driven) forcing in exploited marine ecosystems have been much debated. Examples from a variety of marine systems of exploitation-induced, top-down trophic forcing have led to a general view that human-induced predator perturbations can disrupt entire marine food webs, yet other studies that have found no such evidence provide a counterpoint. Though evidence continues to emerge, an unresolved debate exists regarding both the relative roles of top-down versus bottom-up forcing and the capacity of human exploitation to instigate top-down, community-level effects. Using time-series data for 104 reef communities spanning tropical to temperate Australia from 1992 to 2013, we aimed to quantify relationships among long-term trophic group population density trends, latitude, and exploitation status over a continental-scale biogeographic range. Specifically, we amalgamated two long-term monitoring databases of marine community dynamics to test for significant positive or negative trends in density of each of three key trophic levels (predators, herbivores, and algae) across the entire time series at each of the 104 locations. We found that trophic control tended toward bottom-up driven in tropical systems and top-down driven in temperate systems. Further, alternating long-term population trends across multiple trophic levels (a method of identifying trophic cascades), presumably due to top-down trophic forcing, occurred in roughly fifteen percent of locations where the prerequisite significant predator trends occurred. Such alternating trophic trends were significantly more likely to occur at locations with increasing predator densities over time. Within these locations, we found a marked latitudinal gradient in the prevalence of long-term, alternating trophic group trends, from rare in the tropics (<5% of cases) to relatively common in temperate areas (~45%). Lastly, the strongest trends in predator and algal density occurred in older no-take marine reserves; however, exploitation status did not affect the likelihood of alternating long-term trophic group trends occurring. Our data suggest that the type and degree of trophic forcing in this system are likely related to one or more covariates of latitude, and that ecosystem resiliency to top-down control does not universally vary in this system based on exploitation level.
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Affiliation(s)
- Elizabeth M. P. Madin
- Department of Biological SciencesMacquarie UniversitySydneyNSWAustralia
- School of Life SciencesUniversity of Technology SydneySydneyNSWAustralia
- Hawai'i Institute of Marine BiologyUniversity of Hawai'iKane'oheHIUSA
| | - Joshua S. Madin
- Department of Biological SciencesMacquarie UniversitySydneyNSWAustralia
- Hawai'i Institute of Marine BiologyUniversity of Hawai'iKane'oheHIUSA
| | - Aaron M. T. Harmer
- Department of Biological SciencesMacquarie UniversitySydneyNSWAustralia
- School of Natural and Computational SciencesMassey UniversityAucklandNew Zealand
| | - Neville S. Barrett
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTASAustralia
| | - David J. Booth
- School of Life SciencesUniversity of Technology SydneySydneyNSWAustralia
| | - M. Julian Caley
- School of Mathematical SciencesQueensland University of TechnologyBrisbaneQLDAustralia
- Australian Research Council Centre of Excellence for Mathematical and Statistical FrontiersThe University of MelbourneParkvilleVICAustralia
| | | | - Graham J. Edgar
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTASAustralia
| | | | - Steven D. Gaines
- Bren School of Environmental Science and ManagementUniversity of CaliforniaSanta BarbaraCAUSA
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8
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Wilson KL, Tittensor DP, Worm B, Lotze HK. Incorporating climate change adaptation into marine protected area planning. Glob Chang Biol 2020; 26:3251-3267. [PMID: 32222010 DOI: 10.1111/gcb.15094] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 02/04/2020] [Accepted: 02/24/2020] [Indexed: 05/20/2023]
Abstract
Climate change is increasingly impacting marine protected areas (MPAs) and MPA networks, yet adaptation strategies are rarely incorporated into MPA design and management plans according to the primary scientific literature. Here we review the state of knowledge for adapting existing and future MPAs to climate change and synthesize case studies (n = 27) of how marine conservation planning can respond to shifting environmental conditions. First, we derive a generalized conservation planning framework based on five published frameworks that incorporate climate change adaptation to inform MPA design. We then summarize examples from the scientific literature to assess how conservation goals were defined, vulnerability assessments performed and adaptation strategies incorporated into the design and management of existing or new MPAs. Our analysis revealed that 82% of real-world examples of climate change adaptation in MPA planning derive from tropical reefs, highlighting the need for research in other ecosystems and habitat types. We found contrasting recommendations for adaptation strategies at the planning stage, either focusing only on climate refugia, or aiming for representative protection of areas encompassing the full range of expected climate change impacts. Recommendations for MPA management were more unified and focused on adaptative management approaches. Lastly, we evaluate common barriers to adopting climate change adaptation strategies based on reviewing studies which conducted interviews with MPA managers and other conservation practitioners. This highlights a lack of scientific studies evaluating different adaptation strategies and shortcomings in current governance structures as two major barriers, and we discuss how these could be overcome. Our review provides a comprehensive synthesis of planning frameworks, case studies, adaptation strategies and management actions which can inform a more coordinated global effort to adapt existing and future MPA networks to continued climate change.
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Affiliation(s)
- Kristen L Wilson
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Derek P Tittensor
- Department of Biology, Dalhousie University, Halifax, NS, Canada
- UN Environment World Conservation Monitoring Centre, Cambridge, UK
| | - Boris Worm
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Heike K Lotze
- Department of Biology, Dalhousie University, Halifax, NS, Canada
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Easter EE, Adreani MS, Hamilton SL, Steele MA, Pang S, White JW. Influence of protogynous sex change on recovery of fish populations within marine protected areas. Ecol Appl 2020; 30:e02070. [PMID: 31903628 DOI: 10.1002/eap.2070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 11/04/2019] [Indexed: 06/10/2023]
Abstract
Marine protected areas (MPAs) are increasingly implemented as a conservation tool worldwide. In many cases, they are managed adaptively: the abundance of target species is monitored, and observations are compared to some model-based expectation for the trajectory of population recovery to ensure that the MPA is achieving its goals. Most previous analyses of the transient (short-term) response of populations to the cessation of fishing inside MPAs have dealt only with gonochore (fixed-sex) species. However, many important fishery species are protogynous hermaphrodites (female-to-male sex-changing). Because size-selective harvest will predominantly target males in these species, harvesting not only reduces abundance but also skews the sex ratio toward females. Thus the response to MPA implementation will involve changes in both survival and sex ratio, and ultimately reproductive output. We used an age-structured model of a generic sex-changing fish population to compare transient population dynamics after MPA implementation to those of an otherwise similar gonochore population and examine how different features of sex-changing life history affect those dynamics. We examined both demographically open (most larval recruitment comes from outside the MPA) and demographically closed (most larval recruitment is locally produced) dynamics. Under both scenarios, population recovery of protogynous species takes longer when fishing was more intense pre-MPA (as in gonochores), but also depends heavily on the mating function, the degree to which the sex ratio affects reproduction. If few males are needed and reproduction is not affected by a highly female-biased sex ratio, then population recovery is much faster; if males are a limiting resource, then increases in abundance after MPA implementation are much slower than for gonochores. Unfortunately, the mating function is largely unknown for fishes. In general, we expect that most protogynous species with haremic mating systems will be in the first category (few males needed), though there is at least one example of a fish species (though not a sex-changing species) for which males are limiting. Thus a better understanding of the importance of male fish to population dynamics is needed for the adaptive management of MPAs.
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Affiliation(s)
- E E Easter
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina, 28403, USA
| | - M S Adreani
- Department of Biology, California State University, Northridge, California, 91330, USA
| | - S L Hamilton
- Moss Landing Marine Laboratories, Moss Landing, California, 95309, USA
| | - M A Steele
- Department of Biology, California State University, Northridge, California, 91330, USA
| | - S Pang
- Moss Landing Marine Laboratories, Moss Landing, California, 95309, USA
| | - J W White
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, North Carolina, 28403, USA
- Department of Fisheries and Wildlife, Coastal Oregon Marine Experiment Station, Oregon State University, Newport, Oregon, 97365, USA
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10
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Speed CW, Rees MJ, Cure K, Vaughan B, Meekan MG. Protection from illegal fishing and shark recovery restructures mesopredatory fish communities on a coral reef. Ecol Evol 2019; 9:10553-10566. [PMID: 31624567 PMCID: PMC6787830 DOI: 10.1002/ece3.5575] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 07/13/2019] [Accepted: 07/30/2019] [Indexed: 12/17/2022] Open
Abstract
The recovery of communities of predatory fishes within a no-take marine reserve after the eradication of illegal fishing provides an opportunity to examine the role of sharks and other large-bodied mesopredatory fishes in structuring reef fish communities. We used baited remote underwater video stations to investigate whether an increase in sharks was associated with a change in structure of the mesopredatory fish community at Ashmore Reef, Western Australia. We found an almost fourfold increase in shark abundance in reef habitat from 0.64 hr-1 ± 0.15 SE in 2004, when Ashmore Reef was being fished illegally, to 2.45 hr-1 ± 0.37 in 2016, after eight years of full-time enforcement of the reserve. Shark recovery in reef habitat was accompanied by a two and a half-fold decline in the abundance of small mesopredatory fishes (≤50 cm TL) (14.00 hr-1 ± 3.79 to 5.6 hr-1 ± 1.20) and a concomitant increase in large mesopredatory fishes (≥100 cm TL) from 1.82 hr-1 ± 0.48 to 4.27 hr-1 ± 0.93. In contrast, near-reef habitats showed an increase in abundance of large mesopredatory fishes between years (2.00 hr-1 ± 0.65 to 4.56 hr-1 ± 1.11), although only smaller increases in sharks (0.67 hr-1 ± 0.25 to 1.22 hr-1 ± 0.34) and smaller mesopredatory fishes. Although the abundance of most mesopredatory groups increased with recovery from fishing, we suggest that the large decline of small mesopredatory fish in reef habitat was mostly due to higher predation pressure following the increase in sharks and large mesopredatory fishes. At the regional scale, the structure of fished communities at Ashmore Reef in 2004 resembled those of present day Scott Reefs, where fishing still continues today. In 2016, Ashmore fish communities resembled those of the Rowley Shoals, which have been protected from fishing for decades.
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Affiliation(s)
- Conrad W. Speed
- Australian Institute of Marine ScienceIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
- Global FinPrint ProjectIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
| | - Matthew J. Rees
- Australian Institute of Marine ScienceIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
- Global FinPrint ProjectIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
| | - Katherine Cure
- Australian Institute of Marine ScienceIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
| | - Brigit Vaughan
- Australian Institute of Marine ScienceIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
| | - Mark G. Meekan
- Australian Institute of Marine ScienceIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
- Global FinPrint ProjectIndian Ocean Marine Research CentreUWA (MO96)CrawleyWAAustralia
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11
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Friesen SK, Martone R, Rubidge E, Baggio JA, Ban NC. An approach to incorporating inferred connectivity of adult movement into marine protected area design with limited data. Ecol Appl 2019; 29:e01890. [PMID: 30929286 PMCID: PMC6850429 DOI: 10.1002/eap.1890] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 12/12/2018] [Accepted: 02/20/2019] [Indexed: 05/28/2023]
Abstract
Marine protected areas (MPAs) are important conservation tools that can support the resilience of marine ecosystems. Many countries, including Canada, have committed to protecting at least 10% of their marine areas under the Convention on Biological Diversity's Aichi Target 11, which includes connectivity as a key aspect. Connectivity, the movement of individuals among habitats, can enhance population stability and resilience within and among MPAs. However, little is known about regional spatial patterns of marine ecological connectivity, particularly adult movement. We developed a method to assess and design MPA networks that maximize inferred connectivity within habitat types for adult movement when ecological data are limited. We used the Northern Shelf Bioregion in British Columbia, Canada, to explore two different approaches: (1) evaluating sites important for inferred regional connectivity (termed hotspots) and (2) assessing MPA network configurations based on their overlap with connectivity hotspots and interconnectedness between MPAs. To assess inferred connectivity via adult movement, we used two different threshold distances (15 and 50 km) to capture moderate home ranges, which are most appropriate to consider in MPA design. We applied graph theory to assess inferred connectivity within 16 habitat and depth categories (proxies for distinct ecological communities), and used novel multiplex network methodologies to perform an aggregated assessment of inferred connectivity. We evaluated inferred regional connectivity hotspots based on betweenness and eigenvector centrality metrics, finding that the existing MPA network overlapped a moderate proportion of these regional hotspots and identified key areas to be considered as candidate MPAs. Network density among existing MPAs was low within the individual habitat networks, as well as the multiplex. This work informs an ongoing MPA planning process, and approaches for incorporating connectivity into MPA design when data are limited, with lessons for other contexts.
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Affiliation(s)
- Sarah K. Friesen
- School of Environmental StudiesUniversity of VictoriaVictoriaBritish ColumbiaV8W 2Y2Canada
| | - Rebecca Martone
- Ministry of Forests, Lands, Natural Resource Operations and Rural Development, Province of British ColumbiaVictoriaBritish ColumbiaV8W 9N1Canada
| | - Emily Rubidge
- Institute of Ocean Sciences, Fisheries and Oceans CanadaSidneyBritish ColumbiaV8L 4B2Canada
- Department of Forest and Conservation SciencesUniversity of British ColumbiaVancouverBritish ColumbiaV6T 1Z4Canada
| | - Jacopo A. Baggio
- Department of Political ScienceUniversity of Central FloridaOrlandoFlorida32816USA
- Sustainable Coastal Systems ClusterNational Center for Integrated Coastal ResearchUniversity of Central FloridaOrlandoFlorida32816USA
| | - Natalie C. Ban
- School of Environmental StudiesUniversity of VictoriaVictoriaBritish ColumbiaV8W 2Y2Canada
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12
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Isbert W, Montero FE, Pérez-Del-Olmo A, López-Sanz À, Reñones O, Orejas C. Parasite communities of the white seabream Diplodus sargus sargus in the marine protected area of Medes Islands, north-west Mediterranean Sea. J Fish Biol 2018; 93:586-596. [PMID: 29956313 DOI: 10.1111/jfb.13729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 06/04/2018] [Indexed: 06/08/2023]
Abstract
Marine protected areas are considered a useful tool to preserve and recover the biodiversity of ecosystems. It is suggested that fisheries not only affect populations of target and bycatch species but also their parasite communities. Parasites can indicate fishery effects on host species and also on the whole local community, but the effects of fisheries and protection measures on parasite communities are relatively unknown. This study analyses parasite communities of the white seabream Diplodus sargus sargus in order to assess potential effects exerted by protection measures within and by fisheries outside a reserve in the western Mediterranean Sea. This small scale analysis offered the opportunity to study different degrees of fishery effects on parasite infracommunities, without considering climatic effects as an additional factor. Parasite infracommunities of fishes from the no-take zone (NTZ) differed in their composition and structure compared with areas completely or partially open to fisheries. The detected spatial differences in the infracommunities derived from generalist parasites and varied slightly between transmission strategies. Monoxenous parasites were richer and more diverse in both fished areas, but more abundant in the no-take, whereas richness and abundance of heteroxenous parasites were higher for the NTZ. In addition to host body size as one factor explaining these spatial variations, differences within parasite infracommunities between the areas may also be linked to increased host densities and habitat quality since the implementation of the NTZ and its protection measures.
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Affiliation(s)
- Wolf Isbert
- Cavanilles Institute of Biodiversity and Evolutionary Biology, Valencia, Spain
| | - Francisco E Montero
- Cavanilles Institute of Biodiversity and Evolutionary Biology, Valencia, Spain
| | - Ana Pérez-Del-Olmo
- Cavanilles Institute of Biodiversity and Evolutionary Biology, Valencia, Spain
| | - Àngel López-Sanz
- Instituto de Ciencias del Mar (CSIC), Pg Maritim de la Barceloneta, Barcelona, Spain
| | - Olga Reñones
- Instituto Español de Oceanografía (IEO), Centro Oceanográfico de Baleares (COB), Palma de Mallorca, Spain
| | - Covadonga Orejas
- Instituto de Ciencias del Mar (CSIC), Pg Maritim de la Barceloneta, Barcelona, Spain
- Instituto Español de Oceanografía (IEO), Centro Oceanográfico de Baleares (COB), Palma de Mallorca, Spain
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13
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McGilliard CR, Punt AE, Hilborn R, Essington T. Modeling the impacts of two age-related portfolio effects on recruitment variability with and without a marine reserve. Ecol Appl 2017; 27:1985-2000. [PMID: 28667790 DOI: 10.1002/eap.1593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 05/22/2017] [Accepted: 05/26/2017] [Indexed: 06/07/2023]
Abstract
Many rockfish species are long-lived and thought to be susceptible to being overfished. Hypotheses about the importance of older female rockfish to population persistence have led to arguments that marine reserves are needed to ensure the sustainability of rockfish populations. However, the implications of these hypotheses for rockfish population dynamics are still unclear. We modeled two mechanisms by which reducing the proportion of older fish in a population has been hypothesized to influence sustainability, and explored whether these mechanisms influenced mean population dynamics and recruitment variability. We explored whether populations with these mechanisms could be managed more sustainably with a marine reserve in addition to a constant fishing mortality rate (F) than with a constant F alone. Both hypotheses can be seen as portfolio effects whereby risk of recruitment failure is spread over a "portfolio" of maternal ages. First, we modeled a spawning window effect whereby mothers of different ages spawned in different times or locations (windows) with local environmental conditions. Second, we modeled an offspring size effect whereby older mothers produced larger offspring than younger mothers, where length of a starvation period over which offspring could survive increased with maternal age. Recruitment variability resulting from both models was 55-65% lower than for models without maternal age-related portfolio effects in the absence of fishing and increased with increases in Fs for both models. An offspring size effect caused lower output reproductive rates such that the specified reproductive rate input as a model parameter was no longer the realized rate measured as the reproductive rate observed in model results; this quirk is not addressed in previous analyses of offspring size effects. We conducted a standardization such that offspring size effect and control models had the same observed reproductive rates. A comparison of long-term catch, the probability of falling below a biomass threshold, and recruitment variability over a range of exploitation rates for models with an age-related portfolio effect showed no benefit of a marine reserve implemented in addition to a constant F (as compared to a constant F alone) for populations with sedentary adults and sedentary or mobile larvae.
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Affiliation(s)
- Carey R McGilliard
- School of Aquatic and Fishery Sciences, University of Washington, Box 355020, Seattle, Washington, 98195, USA
- Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration, 7600 Sand Point Way NE, Seattle, Washington, 98115, USA
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14
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Coleman MA, Cetina-Heredia P, Roughan M, Feng M, van Sebille E, Kelaher BP. Anticipating changes to future connectivity within a network of marine protected areas. Glob Chang Biol 2017; 23:3533-3542. [PMID: 28122402 DOI: 10.1111/gcb.13634] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 01/02/2017] [Accepted: 01/06/2017] [Indexed: 06/06/2023]
Abstract
Continental boundary currents are projected to be altered under future scenarios of climate change. As these currents often influence dispersal and connectivity among populations of many marine organisms, changes to boundary currents may have dramatic implications for population persistence. Networks of marine protected areas (MPAs) often aim to maintain connectivity, but anticipation of the scale and extent of climatic impacts on connectivity are required to achieve this critical conservation goal in a future of climate change. For two key marine species (kelp and sea urchins), we use oceanographic modelling to predict how continental boundary currents are likely to change connectivity among a network of MPAs spanning over 1000 km of coastline off the coast of eastern Australia. Overall change in predicted connectivity among pairs of MPAs within the network did not change significantly over and above temporal variation within climatic scenarios, highlighting the need for future studies to incorporate temporal variation in dispersal to robustly anticipate likely change. However, the intricacies of connectivity between different pairs of MPAs were noteworthy. For kelp, poleward connectivity among pairs of MPAs tended to increase in the future, whereas equatorward connectivity tended to decrease. In contrast, for sea urchins, connectivity among pairs of MPAs generally decreased in both directions. Self-seeding within higher-latitude MPAs tended to increase, and the role of low-latitude MPAs as a sink for urchins changed significantly in contrasting ways. These projected changes have the potential to alter important genetic parameters with implications for adaptation and ecosystem vulnerability to climate change. Considering such changes, in the context of managing and designing MPA networks, may ensure that conservation goals are achieved into the future.
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Affiliation(s)
- Melinda A Coleman
- Department of Primary Industries, New South Wales Fisheries, PO Box 4321, Coffs Harbour, NSW, 2450, Australia
- National Marine Science Centre, Southern Cross University, 2 Bay Drive, Coffs Harbour, NSW, 2450, Australia
| | - Paulina Cetina-Heredia
- Regional and Coastal Oceanography Laboratory, School of Mathematics and Statistics, UNSW Australia, Sydney, NSW, 2052, Australia
- Climate Change Research Centre and ARC Centre of Excellence for Climate System Science, UNSW Australia, Sydney, NSW, 2052, Australia
| | - Moninya Roughan
- Regional and Coastal Oceanography Laboratory, School of Mathematics and Statistics, UNSW Australia, Sydney, NSW, 2052, Australia
- Sydney Institute of Marine Science, Mosman, NSW, 2088, Australia
| | - Ming Feng
- CSIRO Oceans & Atmosphere, Indian Ocean Marine Research Centre, M097, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Erik van Sebille
- Climate Change Research Centre and ARC Centre of Excellence for Climate System Science, UNSW Australia, Sydney, NSW, 2052, Australia
- Grantham Institute & Department of Physics, Imperial College London, Exhibition Road, SW7 2AZ London, UK
| | - Brendan P Kelaher
- National Marine Science Centre, Southern Cross University, 2 Bay Drive, Coffs Harbour, NSW, 2450, Australia
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15
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Cabral RB, Gaines SD, Johnson BA, Bell TW, White C. Drivers of redistribution of fishing and non-fishing effort after the implementation of a marine protected area network. Ecol Appl 2017; 27:416-428. [PMID: 28207172 DOI: 10.1002/eap.1446] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 07/25/2016] [Accepted: 08/31/2016] [Indexed: 06/06/2023]
Abstract
Marine spatial planning (MSP) is increasingly utilized to sustainably manage ocean uses. Marine protected areas (MPAs), a form of spatial management in which parts of the ocean are regulated to fishing, are now a common tool in MSP for conserving marine biodiversity and managing fisheries. However, the use of MPAs in MSP often neglects, or simplifies, the redistribution of fishing and non-fishing activities inside and outside of MPAs following their implementation. This redistribution of effort can have important implications for effective MSP. Using long-term (14 yr) aerial surveys of boats at the California Channel Islands, we examined the spatial redistribution of fishing and non-fishing activities and their drivers following MPA establishment. Our data represent 6 yr of information before the implementation of an MPA network and 8 yr after implementation. Different types of boats responded in different ways to the closures, ranging from behaviors by commercial dive boats that support the hypothesis of fishing-the-line, to behaviors by urchin, sport fishing, and recreational boats that support the theory of ideal free distribution. Additionally, we found that boats engaged in recreational activities targeted areas that are sheltered from large waves and located near their home ports, while boats engaged in fishing activities also avoided high wave areas but were not constrained by the distance to their home ports. We did not observe the expected pattern of effort concentration near MPA borders for some boat types; this can be explained by the habitat preference of certain activities (for some activities, the desired habitat attributes are not inside the MPAs), species' biology (species such as urchins where the MPA benefit would likely come from larval export rather than adult spillover), or policy-infraction avoidance. The diversity of boat responses reveals variance from the usual simplified assumption that all extractive boats respond similarly to MPA establishment. Our work is the first empirical study to analyze the response of both commercial and recreational boats to closure. Our results will inform MSP in better accounting for effort redistribution by ocean users in response to the implementation of MPAs and other closures.
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Affiliation(s)
- Reniel B Cabral
- Bren School of Environmental Science and Management, University of California, Santa Barbara, California, 93106, USA
| | - Steven D Gaines
- Bren School of Environmental Science and Management, University of California, Santa Barbara, California, 93106, USA
| | - Brett A Johnson
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California, 93407, USA
| | - Tom W Bell
- Earth Research Institute, University of California, Santa Barbara, California, 93106, USA
| | - Crow White
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, California, 93407, USA
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16
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Waldie PA, Almany GR, Sinclair-Taylor TH, Hamilton RJ, Potuku T, Priest MA, Rhodes KL, Robinson J, Cinner JE, Berumen ML. Restricted grouper reproductive migrations support community-based management. R Soc Open Sci 2016; 3:150694. [PMID: 27069662 PMCID: PMC4821273 DOI: 10.1098/rsos.150694] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/12/2016] [Indexed: 06/05/2023]
Abstract
Conservation commonly requires trade-offs between social and ecological goals. For tropical small-scale fisheries, spatial scales of socially appropriate management are generally small-the median no-take locally managed marine area (LMMA) area throughout the Pacific is less than 1 km(2). This is of particular concern for large coral reef fishes, such as many species of grouper, which migrate to aggregations to spawn. Current data suggest that the catchment areas (i.e. total area from which individuals are drawn) of such aggregations are at spatial scales that preclude effective community-based management with no-take LMMAs. We used acoustic telemetry and tag-returns to examine reproductive migrations and catchment areas of the grouper Epinephelus fuscoguttatus at a spawning aggregation in Papua New Guinea. Protection of the resultant catchment area of approximately 16 km(2) using a no-take LMMA is socially untenable here and throughout much of the Pacific region. However, we found that spawning migrations were skewed towards shorter distances. Consequently, expanding the current 0.2 km(2) no-take LMMA to 1-2 km(2) would protect approximately 30-50% of the spawning population throughout the non-spawning season. Contrasting with current knowledge, our results demonstrate that species with moderate reproductive migrations can be managed at scales congruous with spatially restricted management tools.
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Affiliation(s)
- Peter A. Waldie
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - Glenn R. Almany
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
- CRIOBE—USR 3278, CNRS-EPHE-UPVD and Laboratoire d’Excellence ‘CORAIL’, 58 Avenue Paul Alduy, Perpignan Cedex 66860, France
| | - Tane H. Sinclair-Taylor
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955, Kingdom of Saudi Arabia
| | - Richard J. Hamilton
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
- Indo-Pacific Division, The Nature Conservancy, South Brisbane, Australia
| | - Tapas Potuku
- Kavieng Field Office, The Nature Conservancy, Kavieng, Papua New Guinea
| | - Mark A. Priest
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955, Kingdom of Saudi Arabia
- Marine Spatial Ecology Laboratory and Australian Research Council Centre of Excellence for Coral Reef Studies, School of Biological Sciences, University of Queensland, St Lucia, Queensland 4072, Australia
| | | | - Jan Robinson
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - Joshua E. Cinner
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - Michael L. Berumen
- Red Sea Research Center, Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955, Kingdom of Saudi Arabia
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17
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Bridge TCL, Grech AM, Pressey RL. Factors influencing incidental representation of previously unknown conservation features in marine protected areas. Conserv Biol 2016; 30:154-165. [PMID: 26040905 DOI: 10.1111/cobi.12557] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 05/25/2015] [Indexed: 06/04/2023]
Abstract
Spatially explicit information on species distributions for conservation planning is invariably incomplete; therefore, the use of surrogates is required to represent broad-scale patterns of biodiversity. Despite significant interest in the effectiveness of surrogates for predicting spatial distributions of biodiversity, few researchers have explored questions involving the ability of surrogates to incidentally represent unknown features of conservation interest. We used the Great Barrier Reef marine reserve network to examine factors affecting incidental representation of conservation features that were unknown at the time the reserve network was established. We used spatially explicit information on the distribution of 39 seabed habitats and biological assemblages and the conservation planning software Marxan to examine how incidental representation was affected by the spatial characteristics of the features; the conservation objectives (the minimum proportion of each feature included in no-take areas); the spatial configuration of no-take areas; and the opportunity cost of conservation. Cost was closely and inversely correlated to incidental representation. However, incidental representation was achieved, even in a region with only coarse-scale environmental data, by adopting a precautionary approach that explicitly considered the potential for unknown features. Our results indicate that incidental representation is enhanced by partitioning selection units along biophysical gradients to account for unknown within-feature variability and ensuring that no-take areas are well distributed throughout the region; by setting high conservation objectives that (in this case >33%) maximize the chances of capturing unknown features incidentally; and by carefully considering the designation of cost to planning units when using decision-support tools for reserve design. The lessons learned from incidental representation in the Great Barrier Reef have implications for conservation planning in other regions, particularly those that lack detailed environmental and ecological data.
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Affiliation(s)
- Tom C L Bridge
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, 4811, Australia
- Australian Institute of Marine Science, PMB No. 3, Townsville MC, Queensland, 4810, Australia
| | - Alana M Grech
- Department of Environmental Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
| | - Robert L Pressey
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, 4811, Australia
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18
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Abstract
Models for marine reserve design have been developed primarily with 'reef fish' life histories in mind: sedentary adults in patches connected by larval dispersal. However, many fished species undertake ontogenetic migrations, such as from nursery grounds to adult spawning habitats, and current theory does not fully address the range of reserve options posed by that situation. I modelled a generic species with ontogenetic migration to investigate the possible benefits of reserves under three alternative scenarios. First, the fishery targets adult habitat, and reserves can sustain yields under high exploitation, unless habitat patches are well connected. Second, the fishery targets the nursery, and reserves are highly effective, regardless of connectivity patterns. Third, the fishery targets both habitats, and reserves only succeed if paired on adjacent, well-connected nursery and adult patches. In all cases, reserves can buffer populations against overexploitation but would not enhance fishery yield beyond that achievable by management without reserves. These results summarize the general situations in which management using reserves could be useful for ontogenetically migrating species, and the type of connectivity data needed to inform reserve design.
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Affiliation(s)
- J Wilson White
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC 28403, USA
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19
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White ER, Myers MC, Flemming JM, Baum JK. Shifting elasmobranch community assemblage at Cocos Island--an isolated marine protected area. Conserv Biol 2015; 29:1186-1197. [PMID: 25807991 DOI: 10.1111/cobi.12478] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 12/14/2014] [Indexed: 06/04/2023]
Abstract
Fishing pressure has increased the extinction risk of many elasmobranch (shark and ray) species. Although many countries have established no-take marine reserves, a paucity of monitoring data means it is still unclear if reserves are effectively protecting these species. We examined data collected by a small group of divers over the past 21 years at one of the world's oldest marine protected areas (MPAs), Cocos Island National Park, Costa Rica. We used mixed effects models to determine trends in relative abundance, or probability of occurrence, of 12 monitored elasmobranch species while accounting for variation among observers and from abiotic factors. Eight of 12 species declined significantly over the past 2 decades. We documented decreases in relative abundance for 6 species, including the iconic scalloped hammerhead shark (Sphyrna lewini) (-45%), whitetip reef shark (Triaenodon obesus) (-77%), mobula ray (Mobula spp.) (-78%), and manta ray (Manta birostris) (-89%), and decreases in the probability of occurrence for 2 other species. Several of these species have small home ranges and should be better protected by an MPA, which underscores the notion that declines of marine megafauna will continue unabated in MPAs unless there is adequate enforcement effort to control fishing. In addition, probability of occurrence at Cocos Island of tiger (Galeocerdo cuvier), Galapagos (Carcharhinus galapagensis), blacktip (Carcharhinus limbatus), and whale (Rhincodon typus) sharks increased significantly. The effectiveness of MPAs cannot be evaluated by examining single species because population responses can vary depending on life history traits and vulnerability to fishing pressure.
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Affiliation(s)
- Easton R White
- Department of Biology, University of Victoria, P.O. Box 1700 STN CSC, Victoria, BC, V8W 2Y2, Canada
| | - Mark C Myers
- Department of Biology, University of Northern Iowa, 144 McCollum Science Hall, Cedar Falls, IA, 50614-0421, U.S.A
| | - Joanna Mills Flemming
- Department of Mathematics and Statistics, Dalhousie University, 6316 Coburg Road, P.O. Box 15000, Halifax, NS, B3H 4R2, Canada
| | - Julia K Baum
- Department of Biology, University of Victoria, P.O. Box 1700 STN CSC, Victoria, BC, V8W 2Y2, Canada
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20
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Rizzari JR, Bergseth BJ, Frisch AJ. Impact of conservation areas on trophic interactions between apex predators and herbivores on coral reefs. Conserv Biol 2015; 29:418-429. [PMID: 25185522 DOI: 10.1111/cobi.12385] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 06/26/2014] [Indexed: 06/03/2023]
Abstract
Apex predators are declining at alarming rates due to exploitation by humans, but we have yet to fully discern the impacts of apex predator loss on ecosystem function. In a management context, it is critically important to clarify the role apex predators play in structuring populations of lower trophic levels. Thus, we examined the top-down influence of reef sharks (an apex predator on coral reefs) and mesopredators on large-bodied herbivores. We measured the abundance, size structure, and biomass of apex predators, mesopredators, and herbivores across fished, no-take, and no-entry management zones in the Great Barrier Reef Marine Park, Australia. Shark abundance and mesopredator size and biomass were higher in no-entry zones than in fished and no-take zones, which indicates the viability of strictly enforced human exclusion areas as tools for the conservation of predator communities. Changes in predator populations due to protection in no-entry zones did not have a discernible influence on the density, size, or biomass of different functional groups of herbivorous fishes. The lack of a relationship between predators and herbivores suggests that top-down forces may not play a strong role in regulating large-bodied herbivorous coral reef fish populations. Given this inconsistency with traditional ecological theories of trophic cascades, trophic structures on coral reefs may need to be reassessed to enable the establishment of appropriate and effective management regimes.
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Affiliation(s)
- Justin R Rizzari
- Australian Research Council 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; AIMS@JCU, Australian Institute of Marine Science, James Cook University, Townsville, Queensland, 4811, Australia.
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21
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Rogers A, Harborne AR, Brown CJ, Bozec YM, Castro C, Chollett I, Hock K, Knowland CA, Marshell A, Ortiz JC, Razak T, Roff G, Samper-Villarreal J, Saunders MI, Wolff NH, Mumby PJ. Anticipative management for coral reef ecosystem services in the 21st century. Glob Chang Biol 2015; 21:504-14. [PMID: 25179273 DOI: 10.1111/gcb.12725] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 08/18/2014] [Accepted: 08/18/2014] [Indexed: 05/17/2023]
Abstract
Under projections of global climate change and other stressors, significant changes in the ecology, structure and function of coral reefs are predicted. Current management strategies tend to look to the past to set goals, focusing on halting declines and restoring baseline conditions. Here, we explore a complementary approach to decision making that is based on the anticipation of future changes in ecosystem state, function and services. Reviewing the existing literature and utilizing a scenario planning approach, we explore how the structure of coral reef communities might change in the future in response to global climate change and overfishing. We incorporate uncertainties in our predictions by considering heterogeneity in reef types in relation to structural complexity and primary productivity. We examine 14 ecosystem services provided by reefs, and rate their sensitivity to a range of future scenarios and management options. Our predictions suggest that the efficacy of management is highly dependent on biophysical characteristics and reef state. Reserves are currently widely used and are predicted to remain effective for reefs with high structural complexity. However, when complexity is lost, maximizing service provision requires a broader portfolio of management approaches, including the provision of artificial complexity, coral restoration, fish aggregation devices and herbivore management. Increased use of such management tools will require capacity building and technique refinement and we therefore conclude that diversification of our management toolbox should be considered urgently to prepare for the challenges of managing reefs into the 21st century.
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Affiliation(s)
- Alice Rogers
- Marine Spatial Ecology Laboratory and Australian Research Council Centre of Excellence for Coral Reef Studies, School of Biological Sciences, The University of Queensland, St. Lucia Campus, Brisbane, QLD, 4072, Australia; Marine Spatial Ecology Laboratory, Biosciences, College of Life and Environmental Sciences, Geoffrey Pope Building, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
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22
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Dunlop ES, Baskett ML, Heino M, Dieckmann U. Propensity of marine reserves to reduce the evolutionary effects of fishing in a migratory species. Evol Appl 2015; 2:371-93. [PMID: 25567887 PMCID: PMC3352486 DOI: 10.1111/j.1752-4571.2009.00089.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Accepted: 06/01/2009] [Indexed: 11/30/2022] Open
Abstract
Evolutionary effects of fishing can have unwanted consequences diminishing a fishery's value and sustainability. Reserves, or no-take areas, have been proposed as a management tool for reducing fisheries-induced selection, but their effectiveness for migratory species has remained unexplored. Here we develop an eco-genetic model to predict the effects of marine reserves on fisheries-induced evolution under migration. To represent a stock that undergoes an annual migration between feeding and spawning grounds, we draw model parameters from Atlantic cod (Gadus morhua) in the northern part of its range. Our analysis leads to the following conclusions: (i) a reserve in a stock's feeding grounds, protecting immature and mature fish alike, reduces fisheries-induced evolution, even though protected and unprotected population components mix on the spawning grounds; (ii) in contrast, a reserve in a stock's spawning grounds, protecting only mature fish, has little mitigating effects on fisheries-induced evolution and can sometimes even exacerbate its magnitude; (iii) evolutionary changes that are already underway may be difficult to reverse with a reserve; (iv) directly after a reserve is created or enlarged, most reserve scenarios result in yield losses; and (v) timescale is very important: short-term yield losses immediately after a reserve's creation can give way to long-term gains.
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Affiliation(s)
- Erin S Dunlop
- Institute of Marine Research Bergen, Norway ; Department of Biology, University of Bergen Bergen, Norway ; Evolution and Ecology Program, International Institute for Applied Systems Analysis Laxenburg, Austria ; Ontario Ministry of Natural Resources Peterborough, ON, Canada
| | - Marissa L Baskett
- Department of Environmental Science and Policy, University of California Davis, Davis, CA, USA
| | - Mikko Heino
- Department of Biology, University of Bergen Bergen, Norway ; Institute of Marine Research Bergen, Norway ; Evolution and Ecology Program, International Institute for Applied Systems Analysis Laxenburg, Austria
| | - Ulf Dieckmann
- Evolution and Ecology Program, International Institute for Applied Systems Analysis Laxenburg, Austria
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23
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Olds AD, Connolly RM, Pitt KA, Maxwell PS, Aswani S, Albert S. Incorporating surrogate species and seascape connectivity to improve marine conservation outcomes. Conserv Biol 2014; 28:982-991. [PMID: 24527964 DOI: 10.1111/cobi.12242] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 10/07/2013] [Indexed: 06/03/2023]
Abstract
Conservation focuses on maintaining biodiversity and ecosystem functioning, but gaps in our knowledge of species biology and ecological processes often impede progress. For this reason, focal species and habitats are used as surrogates for multispecies conservation, but species-based approaches are not widely adopted in marine ecosystems. Reserves in the Solomon Islands were designed on the basis of local ecological knowledge to conserve bumphead parrotfish (Bolbometopon muricatum) and to protect food security and ecosystem functioning. Bumphead parrotfish are an iconic threatened species and may be a useful surrogate for multispecies conservation. They move across tropical seascapes throughout their life history, in a pattern of habitat use that is shared with many other species. We examined their value as a conservation surrogate and assessed the importance of seascape connectivity (i.e., the physical connectedness of patches in the seascape) among reefs, mangroves, and seagrass to marine reserve performance. Reserves were designed for bumphead parrotfish, but also enhanced the abundance of other species. Integration of local ecological knowledge and seascape connectivity enhanced the abundance of 17 other harvested fish species in local reserves. This result has important implications for ecosystem functioning and local villagers because many of these species perform important ecological processes and provide the foundation for extensive subsistence fisheries. Our findings suggest greater success in maintaining and restoring marine ecosystems may be achieved when they are managed to conserve surrogate species and preserve functional seascape connections.
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Affiliation(s)
- Andrew D Olds
- Australian Rivers Institute-Coast and Estuaries and School of Environment, Griffith University, Gold Coast QLD 4222, Australia.
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Carter AB, Russ GR, Tobin AJ, Williams AJ, Davies CR, Mapstone BD. Spatial variation in the effects of size and age on reproductive dynamics of common coral trout Plectropomus leopardus. J Fish Biol 2014; 84:1074-1098. [PMID: 24641275 DOI: 10.1111/jfb.12346] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 01/15/2014] [Indexed: 06/03/2023]
Abstract
The effects of size and age on reproductive dynamics of common coral trout Plectropomus leopardus populations were compared between coral reefs open or closed (no-take marine reserves) to fishing and among four geographic regions of the Great Barrier Reef (GBR), Australia. The specific reproductive metrics investigated were the sex ratio, the proportion of vitellogenic females and the spawning fraction of local populations. Sex ratios became increasingly male biased with length and age, as expected for a protogyne, but were more male biased in southern regions of the GBR (Mackay and Storm Cay) than in northern regions (Lizard Island and Townsville) across all lengths and ages. The proportion of vitellogenic females also increased with length and age. Female P. leopardus were capable of daily spawning during the spawning season, but on average spawned every 4·3 days. Mature females spawned most frequently on Townsville reserve reefs (every 2·3 days) and Lizard Island fished reefs (every 3·2 days). Females on Mackay reefs open to fishing showed no evidence of spawning over 4 years of sampling, while females on reserve reefs spawned only once every 2-3 months. No effect of length on spawning frequency was detected. Spawning frequency increased with age on Lizard Island fished reefs, declined with age on Storm Cay fished reefs, and declined with age on reserve reefs in all regions. It is hypothesized that the variation in P. leopardus sex ratios and spawning frequency among GBR regions is primarily driven by water temperature, while no-take management zones influence spawning frequency depending on the region in which the reserve is located. Male bias and lack of spawning activity on southern GBR, where densities of adult P. leopardus are highest, suggest that recruits may be supplied from central or northern GBR. Significant regional variation in reproductive traits suggests that a regional approach to management of P. leopardus is appropriate and highlights the need for considering spatial variation in reproduction where reserves are used as fishery or conservation management tools.
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Affiliation(s)
- A B Carter
- Centre for Sustainable Tropical Fisheries and Aquaculture and School of Earth and Environmental Sciences, James Cook University, Townsville, Qld 4811, Australia; School of Marine and Tropical Biology, James Cook University and ARC Centre of Excellence for Coral Reef Studies, Townsville, Qld 4811, Australia
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Florin AB, Bergström U, Ustups D, Lundström K, Jonsson PR. Effects of a large northern European no-take zone on flatfish populations. J Fish Biol 2013; 83:939-962. [PMID: 24090556 DOI: 10.1111/jfb.12097] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In March 2006, a 360 km² no-take zone (NTZ) was established north of Gotland in the central Baltic Sea, with the purpose to scientifically evaluate the effects of a fishing ban on flatfish populations. A monitoring programme was set up to study the populations in the NTZ and in a reference area east of Gotland where the fishing pressure was high. The programme included fishing with multimesh survey nets, modelling of potential larval export and estimation of fish consumption by large marine predators. Overall, the results showed a clear positive effect of the NTZ on turbot Scophthalmus maximus, with higher densities in the closed area compared with the fished area and also higher densities after closure compared with before. The NTZ also had older individuals and a more even sex ratio. This, in combination with a high potential for larval export from the NTZ to Gotland, shows that the marine reserve may be important for maintaining a viable S. maximus stock at Gotland. Also, for flounder Platichthys flesus, the densities were higher in the NTZ compared to the reference area and there was a net larval export to the fished area. For both species, density-dependent growth was evident, with a lower length at age in the closed area. Potential predation by grey seal Halichoerus grypus and great cormorant Phalacrocorax carbo sinesis on flatfishes, that could hamper the evaluation of the marine reserve, was also addressed. Taken together, the results show that there are clear benefits of the fishing ban for both flatfish species within the NTZ, while the net effects on fisheries are difficult to quantify.
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Affiliation(s)
- A-B Florin
- Institute of Coastal Research, Department of Aquatic Resources, Swedish University of Agricultural Sciences, Skolgatan 6, Öregrund, Sweden
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