Natalie C Ban
email: nban@uvic.ca.

Emily S Darling

Georgina G Gurney

Whitney Friedman

Stacy D Jupiter

W Peni Lestari

Irfan Yulianto

Sinta Pardede

Sukma A R Tarigan

Puji Prihatiningsih

Sangeeta Mangubhai

Vera N Agostini

Rare, Stuart J Campbell

Joachim Claudet

Graham Epstein

Margaret Fox

David Gill

Nyawira A Muthiga

Effects of management objectives and rules on marine conservation outcomes

Keywords: biodiversity outcomes, effectiveness, marine protected areas, MPAs, other effective area-based conservation measures, OECMs

Introduction

As global marine biodiversity continues to decline, efforts to conserve the ocean through areabased management tools are increasing [START_REF] Grorud-Colvert | The MPA Guide: A framework to achieve global goals for the ocean[END_REF]), yet understanding of biodiversity outcomes associated with diverse tools other than marine protected areas (MPAs) is limited (but see [START_REF] Mcclanahan | Biomass-based targets and the management of multispecies coral reef fisheries[END_REF]). Over the past decade, global commitments to the Convention on Biological Diversity (CBD) Aichi Biodiversity Targets have guided national conservation efforts [START_REF] Cbd | Aichi Biodiversity Targets. Convention on Biological Diversity[END_REF][START_REF] Bingham | Sixty years of tracking conservation progress using the World Database on Protected Areas[END_REF]. Parties to the CBD have now agreed to new targets under the Kunming-Montreal Global Biodiversity Framework (CBD 2022) that set the global conservation agenda for the next decade, including the commitment to protect and conserve 30% of the planet's land and oceans by 2030 ('30 x 30). Foundational to the 30x30 target are protected areas, defined as "a geographically defined area, which is designated or regulated and managed to achieve specific conservation objectives" [START_REF] Cbd | Aichi Biodiversity Targets. Convention on Biological Diversity[END_REF]). In the ocean, marine protected areas (MPAs) are an effective conservation tool for biodiversity conservation in some contexts [START_REF] Edgar | Global conservation outcomes depend on marine protected areas with five key features[END_REF]Zupan et al. 2018b), and there is growing recognition that other forms of area-based management can have positive conservation outcomes without conservation-focused objectives (e.g., [START_REF] Jupiter | Locally-managed marine areas: Multiple objectives and diverse strategies[END_REF][START_REF] Gurney | Biodiversity needs every tool in the box: use OECMs[END_REF][START_REF] Reimer | Benefits and gaps in area-based management tools for the ocean Sustainable Development Goal[END_REF].

The potential of area-based management tools other than protected areas to contribute to maintaining biodiversity is now at the forefront of international policy (CBD 2022). Notably, other effective area-based conservation measures (OECMs) are included in the Kunming-Montreal Global Biodiversity Framework, defined as "a geographically defined area other than a Protected Area, which is governed and managed in ways that achieve positive and sustained long-term outcomes for the in situ conservation of biodiversity, with associated ecosystem functions and services and, where applicable, cultural, spiritual, socioeconomic, and other locally relevant values" (CBD 2018). Area-based management has different objectives and applies a diverse suite of rules to achieve those objectives. Assessing conservation effectivess of OECMs is a challenge [START_REF] Claudet | Avoiding the misuse of other effective area-based conservation measures in the wake of the blue economy[END_REF], and an improved understanding of the outcomes for species, resources, and ecosystems is needed to know how different area-based management tools can achieve positive biodiversity outcomes. In particular, protected area coverage is often reported as a positive outcome, but coverage alone does not guarantee benefits for biodiversity [START_REF] Mcclanahan | Biomass-based targets and the management of multispecies coral reef fisheries[END_REF][START_REF] Relano | The 'Paper Park Index': Evaluating Marine Protected Area effectiveness through a global study of stakeholder perceptions[END_REF]. Key gaps in understanding as CBD Parties and the conservation community grapple with the relative role of protected areas and OECMs in meeting global area-based targets to conserve biodiversity include the role of the motivations (i.e., objectives) and rules of different area-based management tools and the role of MPAs and OECMs.

Objectives of marine area-based management tools are diverse. Marine protected areasPAs usually have biodiversity conservation as a primary objective, whereas other managed areas, including those that could potentially be recognized as OECMs, often have a range of objectives, not necessarily including biodiversity conservation. These include sustainable use, fisheries management, community well-being, food security, exclusive local use, and maintaining traditional practices [START_REF] Mcleod | Sasi and Marine Conservation in Raja Ampat, Indonesia[END_REF][START_REF] Jupiter | Locally-managed marine areas: Multiple objectives and diverse strategies[END_REF]. Some studies show that these areas can be successful in meeting ecological and social goals [START_REF] Cinner | Comanagement of coral reef social-ecological systems[END_REF][START_REF] Goetze | Demonstrating multiple benefits from periodically harvested fisheries closures[END_REF].

They are commonly managed by communities for local objectives, whereas MPAs are often implemented and thus managed through government agencies or their designates (UNEP-WCMC et al. 2018). A gap remains in understanding whether area-based management tools with biodiversity-focused objectivesbe they MPAs or other managed areasare more effective at achieving key ecosystem functions, such as sustaining high reef fish biomass, than those with socially focused objectives (e.g., OECMs or other community management types). Coral reef fish biomass is often correlated with coral reef fish species diversity and is a good predictor of fishery yields and therefore a good proxy for biodiversity outcomes and ecosystem services independent of area [START_REF] Mcclanahan | Biogeography versus resource management: how do they compare when prioritizing the management of coral reef fish in the south-western Indian Ocean?[END_REF][START_REF] Mcclanahan | Fisheries yields and species declines in coral reefs[END_REF]. It is used extensively as a measure of area-based conservation outcomes (e.g., [START_REF] Edgar | Global conservation outcomes depend on marine protected areas with five key features[END_REF]Zupan et al. 2018b;[START_REF] Lorenzo | Assessing spillover from marine protected areas and its drivers: A meta-analytical approach[END_REF]).

Studies about the effectiveness of conservation in achieving biodiversity gains (hereafter, conservation effectiveness) commonly focus on levels of protection, with no-take areas thought to be most effective [START_REF] Grorud-Colvert | The MPA Guide: A framework to achieve global goals for the ocean[END_REF]. Formal rules are influential in managing wealthy nation fisheries [START_REF] Melnychuk | Identifying management actions that promote sustainable fisheries[END_REF]), but less is known about relationships between tropical fish biomass and more specific rules-in-use (but see Zupan et al. [2018b]). For areabased management tools focused on fisheries management, rules can include species restrictions (e.g., only some species or sizes can be fished), fishing gear restrictions (e.g., only some gears allowed), and temporal restrictions (e.g., only some times of the year open to fishing) (e.g., Horta e [START_REF] Horta E Costa | A regulation-based classification system for Marine Protected Areas (MPAs)[END_REF][START_REF] Campbell | Fishing restrictions and remoteness deliver conservation outcomes for Indonesia's coral reef fisheries[END_REF]. Whether some of these types of rules are less or more effective at maintaining high reef fish biomass than no-take areas is not fully understood [START_REF] Mcclanahan | Biogeography versus resource management: how do they compare when prioritizing the management of coral reef fish in the south-western Indian Ocean?[END_REF].

Despite numerous studies on the conservation effectiveness of marine area-based management tools, especially MPAs, there has been little research that characterizes how different objectives and rules-in-use can provide conservation benefits. We used the metric of high reef fish biomass.

We sought to examine how conservation outcomes are influenced by the motivations (i.e., objectives) of different forms of area-based management tools and the restrictions therein (i.e., the rules) and how some area-based management tools could qualify under the new concept of OECMs and the enabling conditions that drive their effectiveness. Specifically, we examined the following questions: are there certain rules-in-use that influence the likelihood of having high reef fish biomass; are certain management objectives associated with a greater likelihood of high reef fish biomass; do MPAs and other managed areas achieve sustainable levels of reef fish biomass; how can the definition of and guidance about OECMs (CBD 2018; IUCN-WCPA 2019) be applied to specific area-based management sites when data are limited? We focused on coral reef systems and used data from a multi-country social-ecological systems monitoring effort [START_REF] Gurney | Implementing a social-ecological systems framework for conservation monitoring: lessons from a multi-country coral reef program[END_REF]. We referred to areas that meet the OECM definition but did not yet have consent of governing actors as "potential OECMs." (See Table 1 for our operationalization of the CBD definition.)

Methods

We used data from a social-ecological systems monitoring program of the Wildlife Conservation Society (WCS) developed through a transdisciplinary process: Marine and Coastal Monitoring (MACMON) (Gurney et al. 2019, wcs.org/coral). The WCS has implemented the program in 6 countries across the Indo-Pacific: Kenya, Madagascar, Mauritius, Indonesia, the Solomon Islands, and Fiji (Fig. 1). The MACMON framework is the first marine operationalization and implementation of Nobel prize winner Elinor [START_REF] Ostrom | A general framework for analyzing sustainability of social-ecological systems[END_REF] influential social-ecological systems framework for monitoring conservation practice across multiple countries [START_REF] Cox | Lessons learned from synthetic research projects based on the Ostrom Workshop frameworks[END_REF]. These six countries and the respective sites were included in the monitoring program because they have ongoing spatial management through long-term partnerships with WCS. We used data collected in 126 villages through key informant interviews about the local area-based management rules (n = 381), local country expert validation, and underwater visual censusof reef fishes (895 transects at 201 reef sites). Detailed data collection protocols and interview guides are documented in [START_REF] Gurney | A global social-ecological systems monitoring framework for coastal fisheries management: A practical monitoring handbook[END_REF]

Management categories

We considered 3 types of area-based management tools in our research: MPAs, areas designated as such by their country; other area-based management, areas with area-based management but not designated or reported as MPAs by countries (hereafter other managed areas); and reference sites, areas without active area-based management (Table 1).

We further examined the other managed areas to assess whether any meet the definition of other effective area-based managed area (potential OECM). We include potential because governance authorities had not yet consented to their inclusion as OECMs. Guidelines to assist countries in identifying potential OECMs have been developed by the task force established through the International Union for Conservation of Nature (IUCN) (IUCN-WCPA 2019) and are being drafted by Food and Agriculture Organization of the United Nations (FAO) specifically for the fisheries sector (para. 17[e] of the 34th Session of the FAO Committee on Fisheries) (FAO 2021).

Our study was a first attempt to examine more closely how to operationalize the concept of OECMs drawing on data from monitoring programs across multiple countries. We used the CBD definition (CBD 2018) and IUCN guidelines (IUCN-WCPA 2019) to draft a set of scoping questions to ask experts about each managed area, governance and management arrangements, and long-term intentions (Table 2). These responses were collected from 2020 to 2022. To gauge achievement of positive biodiversity conservation outcomes, we classified sites based on their ability to sustain fish populations above biomass thresholds of reef fishes reported in the literature: biomass of ≥500 kg/ha for sustaining reef functions and ≥1000 kg/ha as akin to unfished areas. We refer to sites that have biomass of ≥500 kg/ha as having high reef fish biomass or high biomass [START_REF] Macneil | Recovery potential of the world's coral reef fishes[END_REF][START_REF] Mcclanahan | Biogeography versus resource management: how do they compare when prioritizing the management of coral reef fish in the south-western Indian Ocean?[END_REF][START_REF] Mcclanahan | Biomass-based targets and the management of multispecies coral reef fisheries[END_REF].

Reef fish biomass is a useful metric for assessing coral reef condition across broad geographies [START_REF] Macneil | Recovery potential of the world's coral reef fishes[END_REF][START_REF] Mcclanahan | Variability in coral reef fish baseline and benchmark biomass in the central and western Indian Ocean provinces[END_REF]) and is linked to many of the objectives of areabased management (e.g., ecosystem health, short-and long-term yields, improved livelihoods) [START_REF] Smallhorn-West | Linking small-scale fisheries co-management to U.N. Sustainable Development Goals[END_REF]. This operationalization was a first attempt to investigate differences in and relationships between biomass, rules, and objectives between MPAs and other forms of area-based management in coral reef social-ecological systems.

Data description

Our focal scale was spatially contiguous areas that shared a common set of rules, which we called zones (n = 95). Eighty zones had area-based management, and 15 were reference sites, where additional area-based management was limited or absent and only national rules applied.

Two countries did not have reference sites (Solomon Islands, Fiji) because all surveyed reefs were managed to some extent within customary fishing ground boundaries.

We summarized information about rules for each zone based on key informant interviews, which specifically asked about rules related to gears, times, and species. We used key informants to identify the rules because not all the zones had written management plans and because we were interested in the rules-in-use (i.e., the rules being followed on the water). In-country experts then reviewed and updated the information based on their local knowledge and experience working at these sites. Each type of rule had four categories: none (no rules), limited, moderate, and all gears, times, or species prohibited (no take) (details in Appendix S2). We developed these categories based on the range of rules provided by key informants. In-country experts shared information about the main management objective or objectives, which we coded into three categories: biodiversity only; social, economic, cultural (SEC); or both. We also coded them into more detailed categories (hereafter detailed objectives) (Appendix S3). In-country experts provided information about the size of the zones and age category (young, <5 years; medium, 5-15 years; old, ≥16 years; including those with customary tenure). Biomass data were collected with standard underwater visual census surveys of belt transects. Data were processed in the open source data application MERMAID (datamermaid.org), which uses standard length-weight conversions for observations of reef fish abundance and size classes. We averaged total reef fish biomass by zone from underwater survey data (mean kilograms per hectare of 22 common coral reef fish species [Appendix S4]). Sixty-eight of the 95 zones had associated biomass data.

Objectives, rules, and reef fish biomass in area-based management tools We used hierarchical cluster analysis of variables to examine the range of objectives and rules used in area-based management and whether some rules or combinations of rules linked to specific objectives. We clustered only the rules, then rules and objectives categories, and finally added management type. This identified co-occurrence across rules, objectives, and management. We ran stability plots to see whether and how many clusters emerged. We visualized objectives and rules by management type (Table 1) and used Fisher's exact tests to explore the relationships. See Appendices S1-S10 for additional details and references.

We used Bayesian multilevel models to examine the effects of objectives, rules, and types of area-based management tools on fish biomass. To better isolate the effects of management from other factors affecting biomass and avoid overparameterization of our models, we first examined the relationship between biomass and the various site attributes summarized at the scale of our analyses (zones): reef habitat type, depth, size and age of managed area, human gravity (function of population size and reef accessibility [START_REF] Cinner | Gravity of human impacts mediates coral reef conservation gains[END_REF]), and distance to deep water (proxy for isolated sites, one of the contributors of large biomass [START_REF] Edgar | Global conservation outcomes depend on marine protected areas with five key features[END_REF]) in a random forest model. Based on the model results of variable importance, we excluded deep water given its limited predictive power (see Appendix S1).

We then ran three separate models for total biomass (log) and rules, objectives, and management, respectively, with normally distributed priors, 10,000 iterations, and four chains. We included the reference sites not locally managed in the models to compare zones with and without areabased management. We treated rules as ordinal factors and tested for linear relationships, hypothesizing that stricter rules would be associated with higher biomass. We coded objectives and management types as categorical variables; each category was compared with a reference category (none for objectives, reference for management). Not all zones had associated biomass data. For analyses that included biomass, we excluded zones with missing data (Table 1). We included standardized covariates (z scores) of depth, size (log), and gravity, fixed factors of management age (ordered factor) and reef habitat (categorical variable), and the random factor country in all models.

Results

In the 80 managed zones from six countries, temporal, gear-, and species-specific rules were applied at varying levels of restrictions (Fig. 2). Gear-use-associated rules were most common.

Objectives that encompassed both biodiversity and social, economic, and cultural (hereafter referred to as 'social') objectives were most common, followed by those with only social objectives (Fig. 3a). When coding objectives in detailed categories (detailed objectives), many detailed objectives existed across all area-based management tools analyzed. Sustainable use was the most common, followed by biodiversity conservation (Fig. 3c).

Various combinations of gear, temporal, and species rules occurred in area-based management, such that rules did not cluster in a meaningful way (Appendix S8). Fisher's exact tests indicated no statistical differences between the rules applied to zones with different categories of objectives. The exception was that species rules were different in zones that had biodiversity versus social objectives and in zones that had both biodiversity and social objectives versus social objectives only (Appendix S5).

The MPAs had the highest proportion of biodiversity-only primary objectives (Fig. 3b,d).

Primary objectives that were either focused on social only or encompassed both biodiversity and social were present for all area-based management tools (Fig. 3). Other managed areas had more diverse objectives than MPAs, whereas MPAs tended to have biodiversity or sustainable use objectives (Appendix S5). Detailed objectives (Fig. 3c andd) had insufficient sample sizes for statistical analyses. Area-based management tools, including MPAs, comprised a range of sometimes similar or the same rules and objectives (Appendix S5). For example, the same rules were found within MPAs and, for instance, locally managed marine areas.

Biomass varied greatly by rules, objectives, and management (Fig. 4), and the Bayesian multilevel model results showed no clear patterns as to which objectives, rules, and area-based management tools had high biomass when accounting for site attributes (Fig. 5). Objectives were not related to biomass, although areas with social and both objectives had the most variability (including the highest biomass), and those with both had the highest median biomass (Fig. 4d).

Plotting the rules pointed to a potentially greater biomass when temporal and gear rules existed compared with having no rules in place and showed high variability for each category of rules (Fig. 4). Similarly, the raw data depicted a pattern of increasing median biomass from reference, MPAs, and other management (Fig. 4e) and for sites that had objectives compared with no objectives (Fig. 4d). Observed patterns in the raw data were partially due to differences in countries, but country effects were accounted for in Bayesian multilevel models (Fig. 5). These models did not show the differences apparent in the raw data; the posterior estimates for MPAs and other management overlapped substantially.

When applying our operationalization of the OECM criteria to other managed sites and considering the ≥500 kg/ha biomass threshold as an indicator of effectiveness, 15 out of 37 (41%) met all criteria (Table 2). Of the five criteria in the definition, achieving positive outcomes for in situ biodiversity, with biomass as an indicator, was most commonly missed. Only five out of 37 zones met all potential OECM criteria at the ≥1000 kg/ha biomass threshold. If the potential OECM criteria were also applied to MPAswhich they currently are notmany MPAs in our study region did not meet them. Twelve of 20 zones (60%) in MPAs did not meet the ≥500 kg/ha biomass threshold, and 11 of 37 did not meet the "governed and managed" criterion (Table 2). Only two out of 20 MPA zones met all potential OECM criteria at the ≥1000 kg/ha biomass threshold. The average biomass in reference sites was 226 kg/ha, compared with 720 kg/ha in other area-based management and 532 kg/ha in MPAs. Breaking down the other area-based management category further, potential OECMs at the ≥500 kg/ha biomass threshold had an average biomass of 788 kg/ha; potential OECMs at the ≥1000 kg/ha biomass threshold had an average biomass of and 1667 kg/ha in pOECM1000; and area-based management that did not meet the OECM criteria had an average biomass of 474 kg/ha. The average biomass for areas-based management that did not meet the OECM criteria was close to 500 kg/ha, largely due to inclusion of certain sites with high biomass that failed to meet other OECM criteria.

Discussion

Our results illustrate the diversity of rules, objectives, and management tools employed in areabased management and that their multiple configurations can lead to reef fish biomass above the sustainability threshold. At the same time, much of our results indicated there were no clear average relationships among the type of area-based management tool (i.e., MPAs or other areabased management), objectives, rules, and high biomass. Our study makes three important contributions to informing discussions regarding the value of different types of management tools in meeting global conservation goals [START_REF] Grorud-Colvert | The MPA Guide: A framework to achieve global goals for the ocean[END_REF][START_REF] Jonas | Equitable and effective area-based conservation: Towards the conserved areas paradigm[END_REF]). We first found that there were many paths to achieving conservation effectiveness: our data included areas characterized by diverse objectives and multiple combinations of temporal, gear, and species rules that could sustain high levels of reef fish biomass. Yet the same categories also had sites with low biomass, and statistical patterns influencing biomass were not discernable. These results highlight the importance of tracking outcomes and supporting a range of locally appropriate area-based management tools in conservation that are achieving conservation outcomes [START_REF] Reimer | Benefits and gaps in area-based management tools for the ocean Sustainable Development Goal[END_REF].

Our results that not all MPAs had conservation objectives also indicated that there was not a consistent application of the CBD MPA definition in practice, consistent with regional interrogations of the World Database of Protected Areas (Jupiter & Govan 2022). Indeed, while MPAs are supposed to have biodiversity conservation as the primary objective as required by the CBD definition, our own experience with what countries report to the CBD highlights that actions to meet these objectives and reporting on progress on meeting these objectives were not always in place (Jupiter & Govan 2022). Tools, such as The MPA Guide, may help resolve definitional challenges in the future and shed light on MPA protection levels (Grorud-Colvert et al. 2021).

Our finding that there were no consistent combinations of objectives or rules associated with high reef fish biomass aligns with research indicating that there is no one-size-fits-all solution to fit all contexts and that management must strive to be locally appropriate for effective outcomes (e.g., [START_REF] Ostrom | Moving beyond panaceas: a multi-tiered diagnostic approach for social-ecological analysis[END_REF]. Other studies show that, if well designed and managed, no-take areas (sensu Horta e Costa et al. 2016)be they MPAs or other managed areasconsistently result in higher biomass than areas that allow some use (e.g., [START_REF] Edgar | Global conservation outcomes depend on marine protected areas with five key features[END_REF][START_REF] Sala | Assessing real progress towards effective ocean protection[END_REF]).

However, together with emerging studies (e.g., [START_REF] Campbell | Fishing restrictions and remoteness deliver conservation outcomes for Indonesia's coral reef fisheries[END_REF][START_REF] Reimer | Benefits and gaps in area-based management tools for the ocean Sustainable Development Goal[END_REF][START_REF] Fidler | Participation, not penalties: Community involvement and equitable governance contribute to more effective multiuse protected areas[END_REF], our findings showed that areas allowing sustainable use can still support biomass above key thresholds. Utilizing multiple area-based management tools -MPAs and other managed areascan help ensure that management fits its social-ecological context and supports diversity and redundancy in the global conservation system in terms of tools and associated governance arrangements [START_REF] Gurney | Biodiversity needs every tool in the box: use OECMs[END_REF]. Similarly, a study about fisheries management actions showed that benefits of having multiple actions are cumulative and that a broad suite of management measures is key to sustaining fish populations [START_REF] Melnychuk | Identifying management actions that promote sustainable fisheries[END_REF]. We suggest that recognizing and supporting the many paths to conservation effectiveness is critical to ensuring a resilient ocean and achieving ambitious targets set out in the Kunming-Montreal Global Biodiversity Framework.

Second, as far as we are aware, we are the first to attempt to show how one could operationalize the OECM concept with real-world social-ecological data [START_REF] Gurney | Implementing a social-ecological systems framework for conservation monitoring: lessons from a multi-country coral reef program[END_REF]. With a combination of data from reef transects, key informant interviews, and expert validation, we were able to apply the definition and identify potential OECMs within multiple countries.

Measuring effectiveness of area-based management tools is a key topic in policy discussion because the OECM definition requires it. We used reef fish biomassa common used indicator for MPA ecological assessments and one that is linked to many objectivesas a feasible and practical metric that can be obtained for coral reef sites [START_REF] Mcclanahan | Variability in coral reef fish baseline and benchmark biomass in the central and western Indian Ocean provinces[END_REF][START_REF] Smallhorn-West | Linking small-scale fisheries co-management to U.N. Sustainable Development Goals[END_REF]. High variability due to environmental factors (e.g., time of day, tides) and methods (e.g., surveyed species, spatial coverage) can make interpretation challenging [START_REF] Mcclanahan | Influence of instantaneous variation on estimates of coral reef fish populations and communities[END_REF]). Future research is needed to ascertain whether the simple biomass metric and thresholds, or indicators, we used for the other elements of the OECM definition are globally relevant and robust indicators of positive biodiversity outcomes. Biomass is, after all, only one aspect of biodiversity and may not fully capture richness, for instance (but see positive relationships between biomass and biodiversity in [START_REF] Mcclanahan | Fisheries yields and species declines in coral reefs[END_REF]).

A danger of not tracking ecosystem-wide outcomes of biodiversity conservation in OECMs is that this could lead to the compartmentalization of conservation [START_REF] Claudet | Avoiding the misuse of other effective area-based conservation measures in the wake of the blue economy[END_REF]. Key questions that require answers for improved operationalization of OECMs include the following.

How should positive biodiversity outcomes be defined so as to reflect perceptions of effectiveness across multiple knowledge systems? Do outcomes need to include increases in biodiversity over time or evidence that biodiversity is larger than in a similar area without management or both? How might appropriate metrics or thresholds vary across regions and habitats? Importantly, indicators should be able to be used to assess the status and achievement of the specific objectives of that area-based management tool [START_REF] Claudet | Improving assessments of marine protected areas[END_REF]. While there is much more to be learned, providing a tractable and consistent way of operationalizing OECMs across multiple contextsas we did in our studywill address a key barrier that the CBD Parties have been facing in trying to use this policy tool and will allow others to expand on our methods for different contexts and data availability.

Third, our study highlights the importance of measuring effectiveness for all area-based management tools, not just for potential OECMs [START_REF] Barnes | Prevent perverse outcomes from global protected area policy[END_REF][START_REF] Gurney | Biodiversity needs every tool in the box: use OECMs[END_REF][START_REF] Jonas | Equitable and effective area-based conservation: Towards the conserved areas paradigm[END_REF]. Currently, MPAs only need to be officially designated to be reported and count toward countries' commitments under the CBD. We found that 60% of zones in MPAs could fail to meet the criteria laid out for OECMs in CBD decision 14/8 (see also Zupan et al. 2018a). This suggests that MPAs are not being sufficiently managed to achieve positive conservation outcomes, perhaps because of capacity limitations [START_REF] Gill | Capacity shortfalls hinder the performance of marine protected areas globally[END_REF] or noncompliance [START_REF] Iacarella | A synthesis of the prevalence and drivers of non-compliance in marine protected areas[END_REF] or because rules are insufficient to protect biodiversity from threats (Zupan et al. 2018a;Zupan et al. 2018b). Monitoring and evaluation can help managers determine whether their rules are effective in their specific social, economic, and cultural contexts. This information can then be used to adaptively manage to achieve the targeted outcomes and objectives.

Following [START_REF] Jonas | Equitable and effective area-based conservation: Towards the conserved areas paradigm[END_REF], we suggest that the criteria laid out in the CBD definition of OECMs should also be applied to MPAs, thereby creating a universal set of outcome-based standards and ensuring that only areas that meet the criteria for effectiveness and equity are counted against global biodiversity targets. We used reef fish biomass as a conservation-relevant outcome because it is commonly tracked and is applicable for multiple objectives. Other potential outcome indicators include avoided biodiversity loss (i.e., comparing outcomes against expected outcomes without the intervention) [START_REF] Pressey | The mismeasure of conservation[END_REF][START_REF] Claudet | Avoiding the misuse of other effective area-based conservation measures in the wake of the blue economy[END_REF]) and social outcomes, such as well-being [START_REF] Mascia | A novel framework for analyzing conservation impacts: evaluation, theory, and marine protected areas[END_REF][START_REF] Ban | Well-being outcomes of marine protected areas[END_REF]. Such outcome-based standards would need mechanisms that provide reasonable locally relevant benchmarks and time frames, including support for managers to monitor and assess sites.

Future studies can improve on our first attempt at illustrating how one could operationalize OECMs and compare them to MPAs and other area-based management tools. First, expanding the social-ecological monitoring program to include other countries and social-ecological contexts would result in a more robust analyses. While our study involved a large effort encompassing six countries and hundreds of underwater transects and key informant interviews, when summarizing these data into zones, the sample size was small and its statistical power limited. Including additional countries could provide insight as to whether our illustration of how one can operationalize OECMs is transferable to other contexts.

Second, whilst snapshot approaches to examining the outcomes of conservation and management are common, especially when they involve a large number of sites across multiple countries (e.g., [START_REF] Persha | Social and Ecological Synergy: Local Rulemaking, Forest Livelihoods, and Biodiversity Conservation[END_REF][START_REF] Oldekop | A global assessment of the social and conservation outcomes of protected areas[END_REF][START_REF] Ban | Well-being outcomes of marine protected areas[END_REF][START_REF] Darling | Social-environmental drivers inform strategic management of coral reefs in the Anthropocene[END_REF][START_REF] Cinner | Meeting fisheries, ecosystem function, and biodiversity goals in a human-dominated world[END_REF], longitudinal data from protected and contextually similar unprotected reference sites allow for more confidence in attributing outcomes to management [START_REF] Ahmadia | Integrating impact evaluation in the design and implementation of monitoring marine protected areas[END_REF][START_REF] Mcclanahan | Fisheries yields and species declines in coral reefs[END_REF]. Continued implementation of social-ecological monitoring to generate long-term data sets (including biomass trends) will help managers and researchers establish causal relationships.

Nevertheless, individual studies at some of our sites with counterfactual or longitudinal data show that management does result in sustained high fish biomass levels (e.g., for Fiji, [START_REF] Jupiter | A social-ecological systems approach to assessing conservation and fisheries outcomes in Fijian locally managed marine areas[END_REF] and for Indonesia, [START_REF] Campbell | Fishing restrictions and remoteness deliver conservation outcomes for Indonesia's coral reef fisheries[END_REF]).

Additional factors and outcomes should be explored. In addition to the objectives and rules we investigated, many studies provide insights into other characteristics associated with marine conservation effectiveness. For example, management capacity [START_REF] Gill | Capacity shortfalls hinder the performance of marine protected areas globally[END_REF]) and socioeconomic characteristics that gauge human impact, such as population density [START_REF] Cinner | Gravity of human impacts mediates coral reef conservation gains[END_REF], among others, are also important. However, data are rarely available on the wide range of potentially influential ecological, social, and institutional factors [START_REF] Wamukota | Co-management of coral reef fisheries: a critical evaluation of the literature[END_REF].

Analyses thus have to contend with data limitations and rely on scattered and incomplete realworld data to provide management and policy advice. Our study was not designed to examine some important factors that could influence conservation outcomes, such as preexisting reef conditions and management, local resource dependency and use patterns, compliance, the politics of management tools designation and implementation, among others [START_REF] Ostrom | A general framework for analyzing sustainability of social-ecological systems[END_REF][START_REF] Gurney | Implementing a social-ecological systems framework for conservation monitoring: lessons from a multi-country coral reef program[END_REF]. Enforcement of the rules and boundaries is also likely to play a key role in achieving outcomes [START_REF] Mcclanahan | Conservation needs exposed by variability in common-pool governance principles[END_REF][START_REF] Mcclanahan | Perceptions of governance effectiveness and fisheries restriction options in a climate refugia[END_REF][START_REF] Iacarella | A synthesis of the prevalence and drivers of non-compliance in marine protected areas[END_REF]. Further assessing other social and biological outcomes will be essential to obtaining a more complete understanding of the value of different area-based management tools [START_REF] Geldmann | Essential indicators for measuring site-based conservation effectiveness in the post-2020 global biodiversity framework[END_REF][START_REF] Reimer | Benefits and gaps in area-based management tools for the ocean Sustainable Development Goal[END_REF].

Our study drew on data from a global monitoring program across six countries (Gurney et al. 2019, wcs.org/coral), which represents one of the largest and most comprehensive sets of data on coral reef social-ecological systems [START_REF] Cox | Lessons learned from synthetic research projects based on the Ostrom Workshop frameworks[END_REF]. Our findings can inform the dialogue in global conservation policy by providing supportive evidence that achieving biodiversity outcomes requires a diversity of rules and tools, which are fit to local context. No matter what tool is used, policy makers and practitioners should ensure relevant governing actors are provided with sufficient support (e.g., recognition, funding, secure rights, capacity) and that programs are designed and managed to strengthen existing local sustainable governance systems, rather than displace or substantially alter them (CBD 2018;[START_REF] Gurney | Biodiversity needs every tool in the box: use OECMs[END_REF]. Engagement in the process of design or management of these must be based on human rights standards and promote equitable governance arrangements [START_REF] Jonas | Other Effective Area-based Conservation Measures: From Aichi Target 11 to the Post-2020 Biodiversity Framework[END_REF]. The recognition, inclusion, and funding of area-based management tools will require governments to mobilize significant resources to meet the global goals of the Kunming-Montreal Global Biodiversity Framework.

With this, the diverse social and ecological goals needed to advance conservation can be met. Zones had to meet all five of the elements of the CBD OECM definition below to be considered "potential OECMs" in our analysis. We refer to them as "potential" OECMs because, while they meet the CBD definition, managers of those areas need to provide their consent and there needs to be a formal assessment process for the areas to be listed as an OECM. in Table 1 andAppendix S3.

Figure 1 .

 1 Figure 1. Location of study sites (a) in 6 counties panels and (b) globally (colors, average reef fish biomass; orange, <500 kg/ha; blue,

Figure 2 .

 2 Figure 2. The numbers and proportion of rules, objectives, and management categories in the 80 area-based management sites in 6

Figure 3 .

 3 Figure 3. Stated objectives for 80 area-based management sites in 6 Indo-Pacific countries: (a) frequency of categories of objectives,

Figure 4 .

 4 Figure 4. Reef fish biomass under (a) temporal, (b) gear, and (c) species rules and under different (d) management objectives and (e)

Figure 5 .

 5 Figure 5. Relationship between (log) reef fish biomass and (a) rules, (b) objectives, and (c) management (points, Bayesian posterior

Table 1 . Descriptions and sample sizes of the area-based management tools and reference areas included in considered in this study on the effects of management objectives and rules on marine conservation outcomes x

 1

	Management category	Description	Sample size	No. of samples
	(abbreviation)			with biomass
				data
	Reference sites (reference)	areas with no area-based management rules	15	11
		beyond those that apply to the whole
		country's waters (e.g., national laws and
		policies)
	Area-based management tools (ABMTs)
	marine protected areas	areas designated as a marine protected area by	37 zones in	20 zones in 9
	(MPAs)	the country in which it is situated; defined	20 MPAs	MPAs
		as "a geographically defined area, which is
		designated or regulated and managed to
		achieve specific conservation objectives"
		(CBD 2006)
	other area-based	areas that have area-based management other	43 zones in	37 zones in 30
	management (other)	than MPAs; includes those that do and do	34 areas	areas
		not meet definition of potential Other
		Effective Area-Based Management (CBD
		2018) (Table 2.

Table 2 .

 2 Application of the Convention on Biological Diversity's (CBD) definition of "other effective areabased conservation measures" (OECMs) to coral reef marine area-based management. a a

  b Method for operationalizing each element used in this study.c The remaining columns indicate how many areas meet the criteria for MPAs and other managed areas, respectively. Not all areas have biomass data.

	Element of CBD	Indicator question b	Data used for	No. marine	No. other
	OECM definition		operationalization	protected	managed areas
				areas	not meeting
				(MPAs) not	criteria c
				meeting
				criteria c
	Geographically	Is managed area well defined	expert assessment	6 out of 37	13 out of 43
	defined	geographically? (yes or no)	(in-country
			experts)
	Other than a	Is area not designated as a	not legally	37 out of 37	0 out of 43
	protected area	marine protected area	recognized as a
		(MPA)? (yes or no)	MPA
	Governed and	Is area governed and managed?	expert assessment	11 out of 37	8 out of 43
	managed	(yes or no)	(in-country
			experts)
	Sustained	Is management intended to be in	expert assessment	4 out of 37	11 out of 43
		place for over ~25 years?	(in-country
		(yes or no)	experts)
	Achieve positive	Does biomass meet or exceed	underwater visual	12 out of 20	15 out of 37
	outcomes for	threshold to sustain reef fish	census of reef	(≥500	(≥500 kg/ha)
	the in situ	productivity and energy	fishes	kg/ha)
	conservation	flows (≥500 kg/ha) or have			32 out of 37
	of biodiversity	biomass akin to unfished		18 out of 20	(≥1000
		areas (≥1000 kg/ha)?		(≥1000	kg/ha)
				kg/ha)

Acknowledgements

This work was supported by the funds provided by NCEAS Science for Nature and People Partnership (SNAPP) to the SNAPP Coastal Outcomes Working Group. Data collection was supported by grants to the Wildlife Conservation Society (WCS) from Bloomberg Philanthropies' Vibrant Oceans Initiative, Blue Action Fund, the John D. and Catherine T. MacArthur Foundation, and Tiffany & Co. Foundation. N.C.B. was supported by NSERC and SSHRC. G.G.G. was supported by the Australian Research Council. We thank all the field staff who collected and verified data (Appendix S7).

Abstract

Understanding the relative effectiveness and enabling conditions of different area-based management tools is essential for supporting efforts that achieve positive biodiversity outcomes as area-based conservation coverage increases to meet newly set international targets. We used data from a coastal social-ecological monitoring program in six Indo-Pacific countries to analyze whether social, ecological, and economic objectives and specific management rules (temporal closures, fishing gear-, species-specific restrictions) were associated with coral reef fish biomass above sustainable yield levels across different types of area-based management tools (i.e., comparing those designated as marine protected areas [MPAs] with other types of area-based management). All categories of objectives, multiple combinations of rules, and all types of areabased management had some sites that were able to sustain high levels of reef fish biomassa key measure for coral reef functioning-compared with reference sites with no area-based management. Yet the same management types also had sites with low biomass. As governments advance their commitments to the Kunming-Montreal Global Biodiversity Framework and the target to conserve 30% of the planet's land and oceans by 2030, we found that although different types of management can be effective, most of the managed areas in our study regions did not meet International Union for the Conservation of Nature criteria for effectiveness. These findings underscore the importance of strong management and governance of managed areas and the need to measure the ecological impact of area-based management rather than counting areas because of their designation. sites with no objectives. Other management and marine protected areas were compared with reference sites. Data from reference sites were included in all models. Details in Appendix S6.


Steering G protein ac.va.on from mGlu heterodimer

Guillaume Lebon

Ins$tut de Génomique Fonc$onnelle, Univeristé de Montpellier, CNRS, INSERM.

Heterodimerisa+on of metabotropic glutamate receptors (mGlus) generates func%onal units that modulate the synapse ac+vity, and displays strong therapeu-c poten-al for trea%ng brain disorders and psychiatry diseases. Here, Wang et al., [START_REF] Wang | Structural insights into dimeriza3on and ac3va3on of the mGlu2-mGlu3 and mGlu2-mGlu4 heterodimers[END_REF] solved the cryoelectron microscopy (cryo-EM) structures of mGlu 2 -mGlu 3 , and mGlu 2 -mGlu 4 heterodimers, in various conforma(onal states, revealing the role of each subunit in the asymmetric signalling of mGlu heterodimers, the molecular basis of their allosteric modula.on and giving a ra$onal to understand which subunit ac#vates the G protein.

The metabotropic glutamate receptors (mGlu) are G protein-coupled receptors that are broadly expressed in the central nervous system and play important roles in neurobiological func%on. There are eight subtypes of mGlu receptors that form homo-and heterodimers, the dimerisa(on being essen(al to their func'on. mGlu heterodimers were reported 2 , including for mGlu 1 -mGlu 5 , mGlu 2 -mGlu 4 , mGlu 2 -mGlu 3 , mGlu 2 -mGlu 7 mainly. The existence of mGlu 2 -mGlu 4 heterodimers in mice brain was recently reported, highligh'ng their physiological importance and poten-al role in brain func%ons and disorders [START_REF] Xiang | Input-specific regula-on of glutamatergic synap-c transmission in the medial prefrontal cortex by mGlu2/mGlu4 receptor heterodimers[END_REF][START_REF] Meng | Nanobody-based sensors reveal a high propor0on of mGlu heterodimers in the brain[END_REF] . The mGlu heterodimers offer new opportuni,es for tuning the synap&c ac#vity. Understanding the molecular basis of their dimeriza(on and asymmetric ac#va#on mechanism has remained unresolved. mGlu homodimers are ac&vated by glutamate binding in the Venus flytrap domains stabilising the close state (c), and ac&ve conforma&on of the VFT dimer (A). These first events trigger the movement of the Cystein Rich domains (CDR) and conserved heptahelical transmembrane domains (7TM) promo%ng inter-subunit molecular contacts and stabilizing the ac've state of the receptor [START_REF] Seven | G-protein ac+va+on by a metabotropic glutamate receptor[END_REF][START_REF] Lin | Structures of Gi-bound metabotropic glutamate receptors mGlu2 and mGlu4[END_REF][START_REF] Koehl | Structural insights into the ac0va0on of metabotropic glutamate receptors[END_REF] . Oppositely, antagonist binding maintains the VFTs in an open state (o) and inac've (R) conforma'on of the dimer, preven(ng the reorganiza(on of both subunits and inhibi(ng the receptor ac(va(on 8 . The twelve cryoEM structures reported in Wang et al. [START_REF] Wang | Structural insights into dimeriza3on and ac3va3on of the mGlu2-mGlu3 and mGlu2-mGlu4 heterodimers[END_REF] illustrate the complexity and diversity of the mGlu 2 -mGlu 3 and mGlu 2 -mGlu 4 dimeriza(on modes, posi%ve allosteric modula%on, signal transduc-on and the mul$ples conforma(on popula&ng the mGlu heterodimer conforma&onal landscape (Roo, Rco, Acc with or without G protein).

The structures of the mGlu 2 -mGlu 3 heterodimer obtained in combina(on with the antagonist LY341495, the mGlu 2 selec%ve Nega%ve allosteric modulator (NAM) NAM563 and the mGlu 3 selec%ve NAM LY2389575 represent diverse inac%ve states of mGlu 2 -mGlu 3 . All adopt a Roo conforma(on of the VFTs but with differences in the 7TM dimeriza9on modes: mode I that is stabilized by cholesterol, mode II and III in which the 7TMs are closer but using different protein-protein interfaces. mGlu 2 -Glu 1).

The transi+on from intermediate inac%ve (Rco) to intermediate ac#ve state (Acc without G protein) of the mGlu 2 -mGlu 3 and mGlu 2 -mGlu 4 heterodimers brings the CRDs in close proximity and the reorganiza4on of the 7TM dimeriza+on mode, as previously described for mGlu homodimer. However, the 7TM interac(ons are shi(ed to an asymmetrical interface with some differences between the two heterodimers. The mGlu 3 subunit is (lted away from the Glu 2 subunit whereas the mGlu 4 is rota(ng an#clockwise by 20 degrees. By combining a muta%on that blocks the G protein binding (F765S) and muta%ons that prevent the binding of glutamate (YADA), the func%onal analysis provides the final demonstra-on that the closure of mGlu 3 is likely sufficient for ac#va#ng the G protein via mGlu 2 7TM, in a trans-ac#va#on mechanism similar to the signal transduc-on mechanism of the heterodimeric GABAB receptor, a member of the class C GPCRs [START_REF] Shen | Structural basis of GABAB receptor-Gi protein coupling[END_REF] .

The next ques%on is what drives G protein ac1va1on by one protomer over the other in mGlu heterodimers? Wang et al. report the structures of mGlu 2 -mGlu 3 in complex with mGlu 2 PAM JNJ40411813 and with the G protein and the mGlu 2 -mGlu 4 in complex with JNJ40411813 and 88178 mGlu 4 PAM. While in the case of the mGlu 2 -mGlu 4 heterodimer, mGlu4 was previously iden3fied as the subunit coupling to the G protein 10 , the G protein is now bound to the mGlu 2 subunit, highligh%ng the ability of mGlu 2 to ac&vate the G protein in the heterodimer. The main parameter driving the iden%ty of the subunit recrui&ng the G protein is suggested to be the respec&ve stability of the 7TM inac%ve state, the less stable favoring G protein binding and ac#va#on. In that respect the conserved tryptophan W782 6.50 in TM6 happens to be central in this mechanism and for controlling the equilibrium between inac%ve and ac%ve state of the helical bundle. The movement of W 6.50 , homologous posi%on of the so-called toggle switch in class A GPCRs, is more constrained in mGlu 2 (W773 6.50 ), due to a hydrogen-bond established with N735 5.47 . In mGlu 4 however, the posi)on 5.47 (S760) is occupied by a serine that cannot form hydrogen-bond W798 6.50 making mGlu 4 more prone for ac'va'ng the G protein. A similar but reverse situa&on takes place at the mGlu 2 -mGlu 3 heterodimer where posi%on 5.47 in mGlu 3 is an aspartate that is be)er H-bond accepter compared to mGlu 2 asparagine, making mGlu 3 7TM inac)ve state more stable and explaining the drive towards mGlu 2 helical bundle for ac/va/ng the G protein.

It is however possible to pharmacologically modulate G protein coupling in mGlu heterodimers by destabilizing the mGlu 2 inac%ve state by using a PAM switching the G protein ac+va+on from mGlu 4 to mGlu 2 , or contrarily by increasing the stability of mGlu 2 7TM inac%ve state using the selec%ve mGlu 2 NAM563 and par$ally recovering some G protein ac#va#on from mGlu 3 7TM. Moreover, allosteric modulators may also act on the ternary structure of the complex as illustrated by the mGlu 4 PAM ADX88178 that unexpectedly targets the interface between mGlu 2 and mGlu 4 7TM, interac-ng with both subunits and triggers G protein ac,va,on through mGlu 4 only. Overall, it becomes then very clear that the allosteric modula.on can be a powerful strategy for taking control of a given mGlu subunit and to orientate the signal outcome of the heterodimer. GPCR func*on can be twisted by molecules that exploits unusual large diversity of binding sites.

The study by Wang et al. is a great example of the mul1ple conforma1on, Roo, Rco, Acc (G protein free), Acc-G protein bound states, that sequen!ally leads to G protein ac#va#on of the mGlu heterodimers (Fig. 1). The ac#va#on mechanism of the mGlu 2 -mGlu 4 and mGlu 2 -mGlu 3 heterodimers open great opportuni(es for subunit selec.vity, providing unique but specific signal transduc2on signature of a given heterodimer. Inac%ve state Roo displays some diversity with different dimeriza2on modes (mode I, II, III). Glutamate binding induces the closure of one VFT that is likely driving the rearrangement of the heterodimer quaternary structure (Rco state). In the ac6ve state structure (Acc), and in the presence of G protein (Acc-G protein), both VFTs bind glutamate and are in closed state but with some differences at the helical bundle interface. The selec%on of the mGlu subunit that ac1vates the G protein is dependent of the respec/ve stability of the inac%ve state of each subunit and can be pharmacologically modulated by ac#ng either in one of the 7TM domain (blue) or at their molecular interface (green).

Figure 1 .

 1 Figure1. Schema/c model of mGlu heterodimer G protein ac/va/on and its allosteric modula'on. Inac%ve state Roo displays some diversity with different dimeriza2on modes (mode I, II, III). Glutamate binding induces the closure of one VFT that is likely driving the rearrangement of the heterodimer quaternary structure (Rco state). In the ac6ve state structure (Acc), and in the presence of G protein (Acc-G protein), both VFTs bind glutamate and are in closed state but with some differences at the helical bundle interface. The selec%on of the mGlu subunit that ac1vates the G protein is dependent of the respec/ve stability of the inac%ve state of each subunit and can be pharmacologically modulated by ac#ng either in one of the 7TM domain (blue) or at their molecular interface (green).

  3 was also captured in a Rco intermediate inac%ve state, in dimeriza%on mode I, with NAM563 bound to mGlu 2 7TM but with an empty and open VFT, whereas mGlu 3 VFT is stabilized in close state by glutamate. The higher glutamate affinity of mGlu 3 is likely giving account for such intermediate inac%ve Rco state. A similar conforma.on is also reported in the presence of glutamate and mGlu 2 PAM JNJ-40411813, but with the difference that a glutamate molecule is bound to the mGlu 2 VFT that remains open. Together such subtle differences in the Rco intermediate inac0ve state highlights part of the first sequen&al reorganiza)on of the VFTs towards the ac#ve state of the receptor (Fig.