Modelling marine protected areas: insights and hurdles

Models provide useful insights into conservation and resource management issues and solutions. Their use to date has highlighted conditions under which no-take marine protected areas (MPAs) may help us to achieve the goals of ecosystem-based management by reducing pressures, and where they might fail to achieve desired goals. For example, static reserve designs are unlikely to achieve desired objectives when applied to mobile species or when compromised by climate-related ecosystem restructuring and range shifts. Modelling tools allow planners to explore a range of options, such as basing MPAs on the presence of dynamic oceanic features, and to evaluate the potential future impacts of alternative interventions compared with ‘no-action’ counterfactuals, under a range of environmental and development scenarios. The modelling environment allows the analyst to test if indicators and management strategies are robust to uncertainties in how the ecosystem (and the broader human–ecosystem combination) operates, including the direct and indirect ecological effects of protection. Moreover, modelling results can be presented at multiple spatial and temporal scales, and relative to ecological, economic and social objectives. This helps to reveal potential ‘surprises', such as regime shifts, trophic cascades and bottlenecks in human responses. Using illustrative examples, this paper briefly covers the history of the use of simulation models for evaluating MPA options, and discusses their utility and limitations for informing protected area management in the marine realm.

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Persistence of mobile species in marine protected areas

Fisheries Research ◽

10.1016/j.fishres.2007.11.023 ◽

2008 ◽

Vol 91 (1) ◽

pp. 69-78 ◽

Cited By ~ 5

Author(s):

Urmila Malvadkar ◽

Alan Hastings

Keyword(s):

Protected Areas ◽

Marine Protected Areas ◽

Mobile Species

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Contrasting effects of marine protected areas on the abundance of two exploited reef fishes at the sub-tropical Houtman Abrolhos Islands, Western Australia

Environmental Conservation ◽

10.1017/s0376892904001274 ◽

2004 ◽

Vol 31 (2) ◽

pp. 160-168 ◽

Cited By ~ 28

Author(s):

K. NARDI ◽

G.P. JONES ◽

M.J. MORAN ◽

Y.W. CHENG

Keyword(s):

Protected Areas ◽

Western Australia ◽

Marine Protected Areas ◽

Fold Increase ◽

Reef Fishes ◽

Spatial And Temporal Scales ◽

Coral Trout ◽

Body Sizes ◽

Equivalent Control ◽

Houtman Abrolhos Islands

A unique assemblage of tropical and temperate marine organisms characterizes the Houtman Abrolhos Islands, four clusters of islands and reefs off the coast of mid-Western Australia. Four reef observation areas or marine protected areas (MPAs) were established in 1994 to examine their value in protecting vulnerable reef fish species, including the sub-tropical wrasse, Choerodon rubescens, and the coral trout, Plectropomus leopardus. In 1993 and 1994 (prior to protection), population densities and body sizes were monitored at two island groups (Easter and Wallabi). At each location, the MPAs and the equivalent ‘control’ areas to remain open to fishing were monitored by underwater visual censuses. These closed and open areas were subsequently monitored four more times between 1995 and 2002 to assess long-term trends in abundance and population structure. Populations of the wrasse, C. rubescens, did not appear to respond to protection, exhibiting irregular fluctuations in both closed and open areas throughout the study. In contrast, although there were no significant increases for P. leopardus for the first three years of closure, after eight years of protection there were significantly larger numbers of P. leopardus in the closed areas. There was a three-fold increase at the Easter Group and a seven-fold increase at the Wallabi Group, relative to open fishing areas, attributed primarily to reduced fishing mortality. Significant closed areas (17% of the P. leopardus habitat) provided substantial stock-wide impacts. The data also indicate that the MPAs can be effective where some forms of fishing (such as lobster fishing) are permitted which are compatible with the objectives of the MPA. While MPAs are clearly an effective tool for increasing the local abundance of some reef fishes, the spatial and temporal scales required for their success may vary among species.

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Managing mobile species with MPAs: the effects of mobility, larval dispersal, and fishing mortality on closure size

ICES Journal of Marine Science ◽

10.1093/icesjms/fsn202 ◽

2008 ◽

Vol 66 (1) ◽

pp. 122-131 ◽

Cited By ~ 54

Author(s):

W. J. F. Le Quesne ◽

Edward A. Codling

Keyword(s):

Protected Areas ◽

Marine Protected Areas ◽

Larval Dispersal ◽

Population Model ◽

Marine Reserves ◽

Spatially Explicit ◽

Fishing Mortality ◽

Mobile Species ◽

Explicit Dynamic ◽

Dynamic Population

Abstract Le Quesne, W. J. F., and Codling, E. A. 2009. Managing mobile species with MPAs: the effects of mobility, larval dispersal, and fishing mortality on closure size. – ICES Journal of Marine Science, 66: 122–131. The use of closed areas (marine protected areas, marine reserves, no-take zones) has been suggested as a possible solution to the perceived global fisheries crisis. However, to optimize the design and evaluate the effectiveness of closed areas, we need to understand the interaction between larval dispersal, adult mobility, and fishing mortality. In this paper, a simple, spatially explicit dynamic population model was developed to examine the effects of these interacting factors on optimal closure size and resulting yields. The effect of using one large or several smaller closed areas was also examined. Our model confirmed previous results: closed areas do not improve the yield of populations that are optimally managed or underexploited and, as mobility increases, optimum closure size increases. The model also predicted some interesting counter-intuitive results; for overexploited stocks, the greatest benefit from closed areas can be obtained for stocks with highest mobility, although this may require closure of 85% of the total area. For the tested parameter settings, adult spillover had greater potential to improve yield than larval export, and using several small closed areas rather than a single larger one had the same effect as increasing the mobility of the population.

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Heterogeneity in fishers' and managers' preferences towards management restrictions and benefits in Kenya

Environmental Conservation ◽

10.1017/s0376892912000197 ◽

2012 ◽

Vol 39 (4) ◽

pp. 357-369 ◽

Cited By ~ 25

Author(s):

TIMOTHY R. MCCLANAHAN ◽

CAROLINE A. ABUNGE ◽

JOSHUA E. CINNER

Keyword(s):

Protected Areas ◽

Marine Protected Areas ◽

Management Strategies ◽

National Level ◽

Minimum Size ◽

Management Tools ◽

Management Actions ◽

Key Stakeholders ◽

Landing Sites ◽

The Government

SUMMARYIncreasing the chances that resource users engage in and comply with management regulations is a continual problem for many conservation initiatives globally. This is particularly common when resource users perceive more personal costs than benefits from specific management actions. Analysis of interviews with managers and fishers from 22 landing sites along the coast of Kenya indicated how key stakeholders perceived the scale of benefits and costs from different management strategies. Potential underlying causes of divergent perceptions towards different management tools were evaluated, including marine protected areas, no-take fisheries closures, gear use, minimum size of fish caught and species restrictions. The analysis identified three distinct opinion groups: (1) a group of nine landing sites that scaled their preference for most management restrictions neutral to low, with exceptions for minimum sizes of captured fish and gear restrictions; (2) a group of eight landing sites that scaled their preference for the above and species restrictions and closed season higher, and were more neutral about closures and marine protected areas; and (3) a group containing four landing sites and the managers’ offices that rated their preference for the above and closed areas and marine protected areas as high. Logistic regression was used to examine whether these groups differed in wealth, education, age, perceptions of disparity in benefits, dependence on fishing and distance to government marine protected areas. The most frequent significant factor was the resource users’ perceived disparity between the benefits of the management to themselves and their communities, with the benefits to the government. Consequently, efforts to reduce this real or perceived disparity are likely to increase adoption and compliance rates. Most widespread positively-viewed restrictions, such as gear use and minimum size of fish, should be promoted at the national level while other restrictions may be more appropriately implemented at the community level.

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Functionality and Effectiveness of Marine Protected Areas in Southeastern Brazilian Waters for Demersal Elasmobranchs

Frontiers in Marine Science ◽

10.3389/fmars.2021.694846 ◽

2021 ◽

Vol 8 ◽

Author(s):

Thamíris C. Karlovic ◽

Renata R. Gomes ◽

Paulo C. Paiva ◽

Elizabeth A. Babcock ◽

June F. Dias

Keyword(s):

Protected Areas ◽

Functional Groups ◽

Relative Abundance ◽

Marine Protected Areas ◽

Community Dynamics ◽

Action Plan ◽

Management Strategies ◽

Species Conservation ◽

Northern Coast ◽

Anthropogenic Pressures

Ensuring the efficacy of Marine Protected Areas (MPAs) requires that adequate management strategies be implemented according to the MPA’s objectives. Within the scope of species conservation, achieving MPA objectives demands understanding of the role played by MPAs for the target species. In 2014, Brazilian stakeholders and experts set the action plan for elasmobranchs’ conservation, which intended to create new protected areas and expand the existing ones. Nevertheless, more than 65% of Brazilian elasmobranch species are threatened by anthropogenic pressures such as fisheries and habitat loss. In addition, their ecological aspects are not well studied, which might jeopardize the success of the proposed actions. To assess the functionality and effectiveness of two no-take MPAs for sixteen demersal species, the Wildlife Refuge of Alcatrazes (WRA) and the Tupinambás Ecological Station (TES), we evaluated the community structure, space-time variations in functional diversity and changes in fishery indicators. Community dynamics were driven by inshore intrusion and time persistent effects of a cold and nutrient-rich water mass, the South Atlantic Central Water, which increased the relative abundance of species, functional groups, and overall diversity. Spatially, the heterogeneity of benthic habitats, due to the action of stronger waves in specific parts of the MPAs, reflects a diverse community of benthic invertebrates, explaining differences in relative abundance and similarities in space use by the functional groups. Regarding effectiveness, the MPAs make up a key network with the surrounding protection areas to support the ecosystem maintenance on the central and northern coast of the São Paulo state. The establishment of the TES has positively influenced the community throughout the years while the recent creation of the WRA may have promoted some improvements in fisheries indicators for a threatened guitarfish. We propose different functions of the Alcatrazes archipelago for each species and suggest some measures to enhance not only elasmobranch conservation but also the MPAs’ effectiveness.

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Multispecies spatial assessment models for the British Columbia groundfish trawl fishery

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f98-205 ◽

1999 ◽

Vol 56 (4) ◽

pp. 601-628 ◽

Cited By ~ 35

Author(s):

Carl J Walters ◽

Ramón Bonfil

Keyword(s):

British Columbia ◽

Protected Areas ◽

Gravity Model ◽

Marine Protected Areas ◽

Management Strategies ◽

Fishing Effort ◽

Catch Per Unit Effort ◽

Trawl Fishery ◽

Spatial Redistribution ◽

Quota Management

A multispecies spatial model is proposed for evaluation of trawl management strategies and tested with data from British Columbia groundfish. Minimum stock sizes are estimated for 16 species using spatial catch per unit effort data; these data indicate that only small proportions of most stocks are exposed to fishing at any time and that exchange rates of fish between the grounds and other habitats are rapid. A gravity model for spatial effort allocation predicts substantial side effects of marine protected areas or discarding of particular species on nontarget species/grounds due to redistribution of fishing effort. Multispecies, multiground delay-difference models are used in conjunction with the gravity model for spatial effort distribution to predict long-term population responses to various regulatory strategies. This simulation suggests that species composition and spatial structure of the fishery are changing slowly due to reduction in abundance of long-lived species, but rapid collapses of target stocks are unlikely due to spatial redistribution of effort in response to local declines. We question whether quota management (individual vessel quotas) can be safely implemented due to extreme uncertainty about current stock sizes and suggest that a better strategy may be to simply denominate fishing rights as individual effort quotas while providing protection for sensitive stocks through carefully placed marine protected areas.

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Defining Cost-Effective Solutions in Designing Marine Protected Areas, Using Systematic Conservation Planning

Frontiers in Marine Science ◽

10.3389/fmars.2021.683271 ◽

2021 ◽

Vol 8 ◽

Author(s):

Ibon Galparsoro ◽

Ángel Borja

Keyword(s):

Protected Areas ◽

Marine Protected Areas ◽

Conservation Planning ◽

Basque Country ◽

Management Strategies ◽

Cost Effective ◽

Environmental Conservation ◽

Environmental Benefits ◽

Systematic Conservation Planning ◽

Economic Costs

Environmental conservation is currently one of the main objectives of marine management. It is agreed that effective management requires evaluating the tradeoffs between protection and economic costs for negatively impacted maritime activities. For these reasons, integrated approaches combining ecological and socio-economic aspects are needed to achieve nature conservation and sustainability targets. Here, we present an approach to identify cost-effective priority marine areas for protection through a Systematic Conservation Planning method, adopting the Basque Country as case study (SE Bay of Biscay). Eight protection scenarios were defined, targeting a combination of protection features: benthic habitats, biological value of cetaceans, birds, macroalgae, and macroinvertebrates, potential provision of ecosystem services, and habitat sensitivity to human activities. In turn, the total fishing pressure produced by artisanal fisheries was adopted as a measure of the socio-economic costs of protection (assuming, for this research, that fishing would be banned in the protected areas). The results indicated that existing marine protected areas (MPAs) were very close to achieving prescribed protection targets, while these targets could be achieved by increasing the size of the existing MPAs. Higher costs were associated with the declaration of areas that were targeting a larger number of protection features. Nevertheless, cost/effectiveness was higher in these cases, with the environmental benefits outweighing a comparatively smaller increase in cost. However, the most cost-effective scenarios were those that included the extension of already existing MPAs. The method implemented can assist managers and decision makers in identifying conservation gaps and ecosystem components that require special attention. In addition, the approach can be used to develop management strategies that may be adopted under different protection scenarios. Thus, the approach proposed here could be used to inform ecosystem-based marine spatial planning.

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How good is your marine protected area at curbing threats?

10.31230/osf.io/2ry6t ◽

2018 ◽

Author(s):

Mirta Zupan

Keyword(s):

Protected Areas ◽

Marine Protected Areas ◽

Marine Protected Area ◽

Human Impacts ◽

Management Strategies ◽

Threat Assessment ◽

Local Scale ◽

Coastal Environments ◽

Multiple Use ◽

Reduction Capacity

Marine protected areas (MPAs) are key tools to mitigate human impacts in coastal environments, promoting sustainable activities to conserve biodiversity. The designation of MPAs alone may not result in the lessening of some human threats, which is highly dependent on management goals and the related specific regulations that are adopted. Here, we develop and operationalize a local threat assessment framework. We develop indices to quantify the effectiveness of MPAs (or individual zones within MPAs in the case of multiple-use MPAs) in reducing anthropogenic extractive and non-extractive threats operating at local scale, focusing specifically on threats that can be managed through MPAs. We apply this framework in 15 Mediterranean MPAs to assess their threat reduction capacity. We show that fully protected areas effectively eliminate extractive activities, whereas the intensity of artisanal and recreational fishing within partially protected areas, paradoxically, is higher than that found outside MPAs, questioning their ability at reaching conservation targets. In addition, both fully and partially protected areas attract non-extractive activities that are potential threats. Overall, only three of the 15 MPAs had lower intensities for the entire set of eight threats considered, in respect to adjacent control unprotected areas. Understanding the intensity and occurrence of human threats operating at the local scale inside and around MPAs is important for assessing MPAs effectiveness in achieving the goals they have been designed for, informing management strategies, and prioritizing specific actions.

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Vital demographic statistics and management of the baldchin groper (Choerodon rubescens) from the Houtman Abrolhos Islands

Marine and Freshwater Research ◽

10.1071/mf05187 ◽

2006 ◽

Vol 57 (5) ◽

pp. 485 ◽

Cited By ~ 16

Author(s):

Kim Nardi ◽

Stephen J. Newman ◽

Michael J. Moran ◽

Geoffrey P. Jones

Keyword(s):

Marine Protected Areas ◽

Stock Assessment ◽

Management Strategies ◽

Gonad Development ◽

Total Mortality ◽

Instantaneous Rate ◽

Mobile Species ◽

Discard Mortality ◽

Aggregation Behaviour ◽

Houtman Abrolhos Islands

In order to evaluate appropriate management strategies, the life history and demography of the baldchin groper (Choerodon rubescens) was examined from speared samples and commercial catches at the Houtman Abrolhos Islands, Western Australia. Ages were estimated from sections of sagittal otoliths, validated by oxytetracycline labelling of fish recaptured after a minimum of 12 months at liberty. Male C. rubescens (n = 147; 373–639 mm) ranged from ages 5 to 20 years, and females (n = 354; 226–610 mm) ranged from 2 to 13 years. The population underwent a transition in dominance from females to males at age 11–12 years and 500–550 mm total length. Gonad development was seasonal and spawning was evident from spring to summer (September–January), with evidence of aggregation behaviour. Indirect estimates of the annual instantaneous rate of natural mortality (M) ranged from 0.05 to 0.58 and total mortality (Z), ranged from 0.21 to 0.56, rendering stock assessment highly uncertain. The limited geographic range, slow growth, long potential life span, protogynous sex change, aggregative spawning and high discard mortality rates render C. rubescens susceptible to overfishing. In order to manage this mobile species successfully, marine protected areas must continue to be supplemented by strict catch controls in fished areas.

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Combining sensitivity and uncertainty analysis to evaluate the impact of management measures with ISIS–Fish: marine protected areas for the Bay of Biscay anchovy (Engraulis encrasicolus) fishery

ICES Journal of Marine Science ◽

10.1093/icesjms/fsq002 ◽

2010 ◽

Vol 67 (5) ◽

pp. 1063-1075 ◽

Cited By ~ 34

Author(s):

Sigrid Lehuta ◽

Stéphanie Mahévas ◽

Pierre Petitgas ◽

Dominique Pelletier

Keyword(s):

Uncertainty Analysis ◽

Protected Areas ◽

Marine Protected Areas ◽

Simulation Models ◽

Bay Of Biscay ◽

Engraulis Encrasicolus ◽

Management Measures ◽

Sensitive Parameters ◽

The Impact ◽

Sensitivity And Uncertainty Analysis

Abstract Lehuta, S., Mahévas, S., Petitgas, P., and Pelletier, D. 2010. Combining sensitivity and uncertainty analysis to evaluate the impact of management measures with ISIS–Fish: marine protected areas for the Bay of Biscay anchovy (Engraulis encrasicolus) fishery. – ICES Journal of Marine Science, 67: 1063–1075. Spatio-seasonal explicit simulation models can predict the impact of spatial management measures on marine fish populations and fishing activities. As fisheries are complex systems, fisheries simulation models are often complex, with many uncertain parameters. Here, the methodology is provided to deliver fishery diagnostics within an uncertainty context using a complex simulation tool. A sensitivity analysis of the model is performed on model outputs using partial least-squares to identify the most sensitive parameters. The impact of several management measures is then simulated using a statistical simulation design taking into account the uncertainty of the selected sensitive parameters. This approach was applied to the Bay of Biscay anchovy stock using the ISIS-Fish (Integration of Spatial Information for Simulation of Fisheries) model to assess the impact of imposing marine protected areas (MPAs) conditionally on parameter uncertainty. The diagnostic appeared to be highly sensitive to the mortality of larvae and juveniles, growth, and reproduction. The uncertainty of the values of these parameters did not permit any of the simulated MPA designs to be proposed. However, according to anchovy catch and biomass, the simulations allowed the low impact of closure duration to be shown and underscored the utility of protecting such key processes as spawning.

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