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NPB (r = 0.2, alpha = 0.9) trajectories under optimal reserve scenarios. Size of circle represents % of the fishery in a reserve. Circle colour represents the % change in yield in a given year compared to the yield that would have occurred without the reserve. Red dashed line shows the NPB trajectory of the optimal constant size (static) reserve strategy. Reserves are implemented in year 1.
Source publication
Well-managed fisheries support healthy ocean ecosystems, coastal livelihoods and food security for millions of people. However, many communities lack the resources to implement effective fisheries management. No-take marine reserves are a ubiquitous management intervention that provide conservation benefits and under certain circumstances can provi...
Contexts in source publication
Context 1
... yields began to exceed status quo yields within 5- 10 years. The time to positive NPB was much longer, generally 10 or more years, when positive NPB values were possible at all. We find the opti- mal strategy for a reserve that is capable of any positive NPB in the long-term is to start at a larger reserve size and decrease in size over time (Fig. 4). Our results contradict previous findings of flexible reserve designs ( Brown et al. 2014), which sug- gested short-term economic losses could be over- come with growing reserve ...
Context 2
... work extends the literature regarding short- term economic losses from marine reserves (Brown et al. 2014), by highlighting market-based solu- tions to this challenge in addition to alternative design configurations. We show that the design of the reserve can improve the economic outcomes of a reserve, especially in the long-term (Figs. 3 and 4). However, unlike Brown et al. (2014), our results show that a strategy that reduces reserve size over time is preferable for a community seek- ing to maximize the short-term economic benefits of a reserve. While reserves covering 20-30% of habitat often maximized long-term yields in our simulations, shrinking reserves with a terminal ...
Citations
... Marine Protected Areas (MPAs) have become a common tool in the marine conservation and fisheries toolkit, particularly in tropical small-scale fisheries. A rich body of literature has studied the benefits that MPAs can have on fisheries through empirical evaluations (Moland et al., 2013;Lenihan et al., 2021) or numerical simulations (Ovando et al., 2016;Millage et al., 2021), and can be largely summed up by increases in species richness, biomass, and catchper-unit effort around MPA boundaries (Micheli et al., 2004;Lester et al., 2009;Lenihan et al., 2021;Medoff et al., 2022). Others have empirically evaluated how the costs of establishing MPAs scale with the duration of the planning phase and size of the MPA to be implemented (McCrea-Strub et al., 2011), or combined surveys and national statistics to estimate the recurrent annual expenditure of MPAs and calculate the budgetary requirements for a global network of MPAs (Balmford et al., 2004). ...
The costs and benefits of customary top-down Marine Protected Areas (MPAs) have been studied at length. But the costs and benefits of community-based MPAs –an increasingly common tool in conservation and fisheries management– remain understudied. Here, we quantify the operational costs of maintaining community-based MPA monitoring programs in nine small-scale fishing communities in Mexico. We then compare these costs to the potential extractive use value of invertebrate and fish biomass contained in the reserves. We find that the annual monitoring costs (median: 1,130 MXN/ha; range: 23-3,561 MXN/ha) represent between 0.3% and 55% of the extractive use value of the biomass contained in the reserves (median: 21.31 thousand MXN/ha; 5.22 - 49/12 thousand MXN/ha). These results suggest that the direct monetary benefits of community-based marine conservation can outweigh the costs of monitoring programs, providing further support for these types of management schemes. While further research should explore other mechanisms that would allow fishers to leverage the non-extractive use value of reserves ( e.g. , tourism) or the non-use value ( i.e. existence value of biodiversity) to sustainably finance their conservation efforts, a stop-gap measure to ensuring long-term monitoring costs are covered might include limited extractive use of resources contained in the reserves.
... However, short-and long-term demand for the biodiversity benefits of MPAs must be secured to achieve sustainability of these instruments (Sala et al., 2013). Demand could potentially come from different sources such as improved fisheries (Barner, 2015), payment for ecosystem schemes (Sorice et al., 2018), sustainable seafood markets (Kaiser & Edwards-Jones, 2006) and price premiums (Ovando et al., 2016). ...
Advocates, practitioners and policy‐makers continue to use and advocate for marine protected areas (MPAs) to meet global ocean protection targets. Yet many of the worlds MPAs, and especially no‐take MPAs, are plagued by poaching and ineffective governance. Using a global dataset on coral reefs as an example, we quantify the potential ecological gains of governing MPAs to increase compliance, which we call the ‘compliance gap’. Using ecological simulations based on model posteriors of joint Bayesian hierarchical models, we demonstrate how increased compliance in no‐take MPAs could nearly double target fish biomass (91% increases in median fish biomass), and result in a 292% higher likelihood of encountering top predators. Achieving these gains and closing the compliance gap necessitates a substantial shift in approach and practice to go beyond optimizing enforcement, and towards governing for compliance. This will require engaging and integrating a broad suite of actors, principles, and practices across three key domains: (i)) harnessing social influence, (ii) integrating equity principles, and (iii) aligning incentives through market‐based instruments. Empowering and shaping communication between actor groups (e.g., between fishers, practitioners, and policy‐makers) using theoretically underpinned approaches from the behavioural sciences is one of the most essential, but often underserved aspects of governing MPAs. We therefore close by highlighting how this cross‐cutting tool could be further integrated in governance to bolster high levels of compliance in MPAs.
... It is evident that all measures taken towards a healthier ecosystem and the recovery of species, will entail short-term economic losses and social constraints in the Gulf of Nicoya, e.g. Ovando et al. (2016). However, there will also be consequences if no actions are taken, due to the further depletion of valuable resources by continued extensive fishing. ...
The Gulf of Nicoya is a highly productive estuary located at the Pacific coast of Costa Rica. Previous studies have used trophic models to examine changes in the biomass of key species and in the food web in the last 25 years, revealing an overfished, degraded system with decreasing biomass of valuable target species. The ecosystem degradation was mainly driven by intensive fishing, while climate variations affected resource productivity additionally. This study tested the effectiveness of alternative scenarios including combinations of the current top-down fishing policy and the ban on shrimp trawling, together with a participatory management scenario developed in a previously performed stakeholder workshop. In parallel, the automated fishing policy search of the Ecopath with Ecosim (EwE) software was used to explore an optimized alternative management scenario. The analysis indicates that the ban on trawling is an important measure to allow for the recovery of certain target species, such as shrimps, demersal fish and their predators. However, this ban would not suffice to substantially rebuild the biomass of all key species in the system. Thus, two possible alternative management scenarios are proposed: in the first one, the economic losses are minimized, ecosystem health increases by 10% (by rebuilding target species biomass) and employment provided by fishing decreases (−15%). In the second scenario, higher economic losses are accepted (mainly for the semi-industrial fisheries sector) which allows for a higher increase in ecosystem health and biodiversity. Both scenarios call for additional reductions in fishing efforts, mainly by the semi-industrial purse-seine fleet and the artisanal longline fleet. This study exemplifies how holistic ecosystem models can be used for management advice, future policymaking and how stakeholders can be engaged in this process.
... It was found that establishments of MPA had been linked to frequent disruption of people's lives, via the instilled fear of losing their livelihoods or of forced resettlement that triggered anxiety, threat, and a sense of loss as well as displacement (Mascia and Claus 2009;Dalton, Forrester, and Pollnac 2012;Stevenson, Tissot, and Walsh 2013;Ayer et al. 2018;McNeill, Clifton, and Harvey 2018) Several important studies had demonstrated that support for and success of many MPAs was dependent on positive perception of local stakeholders towards the MPA (Singleton 2009;Dalton, Forrester, and Pollnac 2012;Rees et al. 2013;Bennett et al. 2014;Darling 2014;López-Angarita et al. 2014). Without support from key stakeholder groups, MPAs may only exist on maps and legislatively as 'paper parks' , while offering little to non-real protection to the ocean's ecosystems (Charles et al. 2016;Matera 2016;Ovando, Dougherty, and Wilson 2016;Partelow et al. 2018). Estimates on the percentage of MPAs that exist primarily on paper ranged as high as 80% to 90% worldwide (Masud and Kari 2015;Katikiro 2016;Mahajan and Daw 2016). ...
... Most of the stakeholder engagement work in decision making of MPAs had focused primarily on fisher communities (Charles et al. 2016;Matera 2016;Ovando, Dougherty, and Wilson 2016;Partelow et al. 2018). However recent works on management of MPAs have identified youths as a major stakeholder group that is missing from key consultation sessions and is needing more research engagement (Charles et al. 2016;Matera 2016;Ovando, Dougherty, and Wilson 2016;Partelow et al. 2018). ...
... Most of the stakeholder engagement work in decision making of MPAs had focused primarily on fisher communities (Charles et al. 2016;Matera 2016;Ovando, Dougherty, and Wilson 2016;Partelow et al. 2018). However recent works on management of MPAs have identified youths as a major stakeholder group that is missing from key consultation sessions and is needing more research engagement (Charles et al. 2016;Matera 2016;Ovando, Dougherty, and Wilson 2016;Partelow et al. 2018). The fact that representation of youths was underexplored in the current literature suggests missed opportunities for the increased success and sustainable implementation of MPAs particularly for longer term impact that would be felt by the younger generations (Cárdenas and Lew 2016;Spenceley 2017;Rhormens, Pedrini, and Ghilardi-Lopes 2017;Getzner, Jungmeier and Špika, 2016). ...
Successful buy-in and support for management of Marine Protected Areas (MPA) should acknowledge the existing cultural ecosystem services and their connections to the well-being of local communities to gain positive perceptions. It is necessary to engage local stakeholders, especially among the youths, to explore governance complexities of MPAs and how to better understand cultural ecosystem services. Thus, this qualitative study investigated the perceptions of youths on cultural ecosystem services using a visual method, namely photovoice, as part of the participatory research in a newly established MPA of Tun Mustapha Park, Sabah. Three themes were identified in the process, namely social, economic, and environment. The engagement demonstrated the value of using the participatory approach, which yielded important insights of youths as a part of the community, which included the need for additional livelihood means post-establishment of MPA and issues of degradation of the marine environment. This paper contributed to the MPA governance literature specifically on the empirical youth perception which has been underrepresented as well as the employment of visual participatory methods to encourage better expression among the youths towards their living environment.
... MPAs are a promising management tool for the conservation and recovery of marine ecosystems (Leenhardt et al. 2015, Giakoumi et al. 2017, as well as for fisheries management (Kaiser et al. 2007, Di Franco et al. 2016, Petza et al. 2017, Fraschetti et al. 2018, Petza et al. 2021. MPAs protect fish stocks in the no-take zone, promote greater reproductive output (Kaiser et al. 2007) and therefore sustain density dependent spill-over (Di Lorenzo et al. 2016) enhancing fisheries catches in the buffer zone and outside the MPAs (Hilborn et al. 2004, Kerwath et al. 2013, Ovando et al. 2016 MPAs are generally established as permanent closures (Game et al. 2009), but marine systems are dynamic in space and time (Halpern et al. 2015, Gordon et al. 2018, Kroeker et al. 2020, which has generated arguments in favor of more dynamic and adaptive MPA designs (Grafton & Kompas 2005, Hughes et al. 2007, Hobday & Hartmann 2006. Therefore, the assessment of new MPAS should quantify the spatiotemporal dynamics of priority areas. ...
Marine Protected Areas (MPAs) are a promising management tool for the conservation and recovery of marine ecosystems, as well as fisheries management. MPAs are generally established as permanent closures but marine systems are dynamic, which has generated debate in favour of more dynamic designs. As a consequence, the identification of priority areas should assess their persistence in space and time. Here, we develop a step-by-step approach to assess the spatiotemporal dynamics of fisheries management priority areas using standard fishery-independent survey data. To do so, we fit Bayesian hierarchical spatiotemporal SDM models to different commercially important demersal species and use the resulting maps to fit different spatial prioritisation configurations. We use these results to assess the spatiotemporal dynamics of fisheries priority areas. The proposed method is illustrated through a western Mediterranean case study using fishery-independent trawl survey data on six commercially important species collected over 17 years. We identified two fisheries priority area patterns in the study area, each predominant during a different time-period of the study, asserting the importance of regularly re-assessing MPA designs.
... These impacts can include a variety of positive or negative outcomes, across different aspects of well-being (e.g., economic, social, cultural, political, health, and physical assets), which may differ based on proximity, by subgroups and over short-and long-time scales (Mascia et al., 2010;Ban et al., 2019a;Gill et al., 2019;Rasheed, 2020). Over longer time scales, benefits to local populations may accrue from the recovery of ecosystems or fisheries; however, in the short term resource users may lose access to the resource (Guidetti and Claudet, 2010;Edgar et al., 2014;Ovando et al., 2016). While a recent review shows that most MPAs lead to benefits for human well-being (Ban et al., 2019a), other analyses suggest that many of the burdens of conservation fall on local communities who may already be politically or economically marginalized (Kamat, 2018;Sowman and Sunde, 2018). ...
Substantial efforts and investments are being made to increase the scale and improve the effectiveness of marine conservation globally. Though it is mandated by international law and central to conservation policy, less attention has been given to how to operationalize social equity in and through the pursuit of marine conservation. In this article, we aim to bring greater attention to this topic through reviewing how social equity can be better integrated in marine conservation policy and practice. Advancing social equity in marine conservation requires directing attention to: recognition through acknowledgment and respect for diverse peoples and perspectives; fair distribution of impacts through maximizing benefits and minimizing burdens; procedures through fostering participation in decision-making and good governance; management through championing and supporting local involvement and leadership; the environment through ensuring the efficacy of conservation actions and adequacy of management to ensure benefits to nature and people; and the structural barriers to and institutional roots of inequity in conservation. We then discuss the role of various conservation organizations in advancing social equity in marine conservation and identify the capacities these organizations need to build. We urge the marine conservation community, including governments, non-governmental organizations and donors, to commit to the pursuit of socially equitable conservation.
... Numerous factors influence the population-level effects of MPAs. These include the scale of adult and larval dispersal relative to the size of the MPAs ; strength, timing, and location of density dependence (Burgess et al., 2014); design of the network (Gaines et al., 2010;Rassweiler et al., 2014); degree of enforcement (Edgar et al., 2014); level of fishing pressure; time span under evaluation; and how fishing and management responds to the implementation of the MPAs (Walters et al., 2000;Botsford et al., 2003;Gerber et al., 2003;Smith & Wilen, 2003;Hilborn et al., 2004;Gaines et al., 2010;White et al., 2011;Moffitt et al., 2013;Ovando et al., 2016;Jaco & Steele, 2020). This largely theoretical literature is generally based on modeling of closed populations with some fraction protected inside MPAs. ...
Marine protected areas (MPAs) cover 3-7% of the world's ocean, and international organizations call for 30% coverage by 2030. Although numerous studies show that MPAs produce conservation benefits inside their borders, many MPAs are also justified on the grounds that they confer conservation benefits to the connected populations that span beyond their borders. A network of MPAs covering roughly 20% of the Channel Islands National Marine Sanctuary was established in 2003, with a goal of providing regional conservation and fishery benefits. We used a spatially explicit bioeconomic simulation model and a Bayesian difference-in-difference regression to examine the conditions under which MPAs can provide population-level conservation benefits inside and outside their borders and to assess evidence of those benefits in the Channel Islands. As of 2017, we estimated that biomass densities of targeted fin-fish had a median value 81% higher (90% credible interval: 23-148) inside the Channel Island MPAs than outside. However, we found no clear effect of these MPAs on mean total biomass densities at the population level: estimated median effect was -7% (90% credible interval: -31 to 23) from 2015 to 2017. Our simulation model showed that effect sizes of MPAs of <30% were likely to be difficult to detect (even when they were present); smaller effect sizes (which are likely to be common) were even harder to detect. Clearly, communicating expectations and uncertainties around MPAs is critical to ensuring that MPAs are effective. We provide a novel assessment of the population-level effects of a large MPA network across many different species of targeted fin-fish, and our results offer guidance for communities charged with monitoring and adapting MPAs.
... Numerous factors influence the population-level effects of MPAs. These include the scale of adult and larval dispersal relative to the size of the MPAs ; strength, timing, and location of density dependence (Burgess et al., 2014); design of the network (Gaines et al., 2010;Rassweiler et al., 2014); degree of enforcement (Edgar et al., 2014); level of fishing pressure; time span under evaluation; and how fishing and management responds to the implementation of the MPAs (Walters et al., 2000;Botsford et al., 2003;Gerber et al., 2003;Smith & Wilen, 2003;Hilborn et al., 2004;Gaines et al., 2010;White et al., 2011;Moffitt et al., 2013;Ovando et al., 2016;Jaco & Steele, 2020). This largely theoretical literature is generally based on modeling of closed populations with some fraction protected inside MPAs. ...
... Additionally, both processes can increase fishing effort in the remaining fishing grounds or promote the departure of fishers out of the closure area or the fishing profession [23,40]. Moreover, the time scales of these changes and potential benefits are critical for fishers and managers that are frequently challenged economically to bridge a period of lost yields during this recovery period [45,47]. ...
The long-term consequences of managing overfished fisheries through either gear restrictions or closures are among the many dilemmas facing small-scale fisheries managers. To evaluate long-term outcomes, fishing effort and catch were measured from 1995 to 2019 in two districts in Kenya, one that established a marine reserve in 1991 and another that eliminated destructive small-meshed drag nets beginning in 2001. Stock biomass in the 12 studied landing sites were below multispecies maximum sustainable yield (MMSY) and effort declined in all sites, indicating overfishing. Both interventions showed positive responses in catch per unit effort (CPUE) trends that indicated successful management but the changes were more sustained in the closure-adjacent than the gear-restricted landing sites. For example, total per-area yields in the gear-restricted sites declined steadily to an equilibrium that was 30% below the predicted MMSY. In contrast, and despite the low stock levels, closure-adjacent landing sites maintained yields near MMSY over the full time series. This is likely due to an increase in fish recovery rates by ~42% from an r of 0.23 to an r of 0.34 in the presence of a closure. The study suggests that closures that occupy ~30% of the nearshore fishing grounds could prevent suboptimal yields and fisheries collapse in nearshore East African reefs.
... For model tractability and application at a global scale, we report changes to catch following protection as steady-state forecasted values that are not attached to specific time frames but note that fishery closures typically result in short-term reductions in catch (67-69) before achieving these benefits. Previous analyses suggest that stocks will take an average of 10 y to recover to their premanagement intervention state following conventional management reform (1) and MPA implementation (67,68). It will take 35 y on average to recover a stock to a biologically healthy level (i.e., the ratio of in-water fish biomass to the biomass that would provide maximum sustainable yield, or B/ B MSY , is greater than 0.8) when implementing fisheries management reform (1) or to 90% of unfished biomass inside fully protected MPAs (45). ...
Significance
Strategically siting marine protected areas (MPAs) in overfished fisheries can have important conservation and food provisioning benefits. We use distribution data for 1,338 commercially important fisheries stocks around the world to model how MPAs in different locations would affect catch. We show that strategically expanding the existing global MPA network by just 5% can improve future catch by at least 20%. Our work demonstrates that a global network of MPAs designed to improve fisheries productivity can substantially increase future catch, enabling synergistic conservation and food provisioning.
