Tuobang Li

Infer metabolic directions and magnitudes from moment differences of mass-weighted intensity distributions

Metabolic pathways are fundamental maps in biochemistry that detail how molecules are transformed through various reactions. Metabolomics refers to the large-scale study of small molecules. Highthroughput, untargeted, mass spectrometry-based metabolomics experiments typically depend on libraries for structural annotation, which is necessary for pathway analysis. However, only a small fraction of spectra can be matched to known structures in these libraries and only a portion of annotated metabolites can be associated with specific pathways, considering that numerous pathways are yet to be discovered. The complexity of metabolic pathways, where a single compound can play a part in multiple pathways, poses an additional challenge. This study introduces a different concept: mass-weighted intensity distribution, which is the empirical distribution of the intensities times their associated m/z values. Analysis of COVID-19 and mouse brain datasets shows that by estimating the differences of the point estimations of these distributions, it becomes possible to infer the metabolic directions and magnitudes without requiring knowledge of the exact chemical structures of these compounds and their related pathways. The overall metabolic momentum map, named as momentome, has the potential to bypass the current bottleneck and provide fresh insights into metabolomics studies. This brief report thus provides a mathematical framing for a classic biological concept.

metabolism | mass spectra | moments M etabolic pathways consist of enzyme-mediated biochem- ical reactions that are commonly categorized into two main processes within a living organism: biosynthesis (known as anabolism) and breakdown (known as catabolism) of molecules. Since the discovery of zymase by Buchner and Rapp in 1897 [START_REF] Buchner | Alkoholische gährung ohne hefezellen[END_REF] and urea cycle by Krebs and Henseleit in 1932 (2), a vast body of metabolic pathway knowledge has grown over the last centuries, especially aided by the development of analytical techniques such as chromatography, NMR and mass spectrometry. Despite that, many metabolic pathways are still undiscovered or poorly understood. High-throughput mass spectrometry experiments can collect thousands of mass spectra in just minutes, giving mass spectrometry a unique advantage compared to other analytical methods. The fragmentation pattern of a molecule, or the mass spectrum, can provide valuable structural information about the molecule. However, annotation of these spectra is typically restricted to compounds for which reference spectra are present in libraries or databases [START_REF] Wang | Sharing and community curation of mass spectrometry data with global natural products social molecular networking[END_REF][START_REF] Wang | Mass spectrometry searches using masst[END_REF][START_REF] Kind | Fiehnlib: Mass spectral and retention index libraries for metabolomics based on quadrupole and time-of-flight gas chromatography/mass spectrometry[END_REF][START_REF] Dührkop | Searching molecular structure databases with tandem mass spectra using csi:fingerid[END_REF]. Only a small fraction of spectra can be accurately assigned precise chemical structures in nontargeted tandem mass spectrometry studies, a prerequisite for pathway analysis [START_REF] Rr Da Silva | Illuminating the dark matter in metabolomics[END_REF][START_REF] Dührkop | Systematic classification of unknown metabolites using high-resolution fragmentation mass spectra[END_REF]. Another challenge arises from the complexity of metabolic pathways, where one compound can be part of several pathways. The change in the amount of certain compounds cannot conclusively determine the metabolic direction of a specific pathway. For example, glucose can be catabolized through glycolysis to produce ATP, or it can be stored as glycogen, or converted to fat. Therefore, an decrease in glucose levels could be due to increased glycolysis, glycogen synthesis, or fat synthesis. Integrating with transcriptomics and/or proteomics can provide a more holistic understanding of metabolism, however, their complexity still make it difficult to clearly interpret the results. Recent developments of in silico methods in class assignment of nontargeted mass spectrometry data can achieve very high prediction performance [START_REF] Dührkop | Searching molecular structure databases with tandem mass spectra using csi:fingerid[END_REF][START_REF] Sr Lowry | Comparison of various k-nearest neighbor voting schemes with the selftraining interpretive and retrieval system for identifying molecular substructures from mass spectral data[END_REF][START_REF] Jd Watrous | Mass spectral molecular networking of living microbial colonies[END_REF][START_REF] Nothias | Feature-based molecular networking in the gnps analysis environment[END_REF][START_REF] Tsugawa | A cheminformatics approach to characterize metabolomes in stable-isotopelabeled organisms[END_REF][START_REF] Dührkop | Sirius 4: a rapid tool for turning tandem mass spectra into metabolite structure information[END_REF][START_REF] Aa Aksenov | Auto-deconvolution and molecular networking of gas chromatography-mass spectrometry data[END_REF][START_REF] Hoffmann | High-confidence structural annotation of metabolites absent from spectral libraries[END_REF][START_REF] Petras | Gnps dashboard: collaborative exploration of mass spectrometry data in the web browser[END_REF][START_REF] Nj Morehouse | Annotation of natural product compound families using molecular networking topology and structural similarity fingerprinting[END_REF][START_REF] Goldman | Annotating metabolite mass spectra with domain-inspired chemical formula transformers[END_REF]. The classification of metabolites is based on chemical characteristics, such as their substructures or chemical groups. While this approach can provide useful information about the chemical properties of metabolites, they may not directly reflect their interactions within the cell. Moreover, the total amount of certain classes of metabolites may remain relatively constant within groups, even if individual compounds within these classes differ.

The purpose of this brief report is to introduce a different approach to quantitatively infer the metabolic directions and magnitudes of metabolites of interest without knowing their exact chemical structures and related specific pathways. Classical view of metabolism mainly focuses on individual reactions, so the metabolic directions are anabolic or catabolic. If we consider the combinations of them, then, two new metabolic directions arises, i.e., centrabolic and duobolic. The concept, metabolic momentum, offers a more accessible and biologically explainable framework, with the potential to significantly advance our understanding of metabolic pathways.

Definitions

The data generated from mass spectroscopy experiments usually consist of two main components: the mass-to-charge ratio (m/z) and its corresponding intensity. The m/z value represents the mass of the ion (when the charge is +1), while the intensity is a measure of the relative abundance of ions present at that specific m/z value in the mass spectrum. Let C1,n represent the first column, which includes the m/z data, and C2,n represent the second column, which includes the corresponding intensity. The mass-weighted intensity distribution of sample A of n molecules of interest is defined as the empirical distribution of C1,n,AC2,n,A. The location estimate of C1,n,AC2,n,A is denoted as Ln,A. As the mass-weighted intensity distribution represents the concentrations of molecules of interest in the sample, weighted by their respective masses, in the same study, T.L. designed research, performed research, analyzed data, and wrote the paper.

The author declares no competing interest. Mass-weighted intensity distributions were computed for each sample and then pooled for each group. The location and scale estimations of mass-weighted intensity distributions were then performed on each group. To determine the uncertainty associated with the differences in location and scale estimations between groups, a bootstrap method was applied. Bootstrap resampling involves generating multiple random samples with replacement from the original dataset. In this study, 1000 bootstrap iterations were performed. For each iteration, the location and scale estimations were recalculated for each group. The bootstrap results were used to estimate the 95% confidence intervals of the differences between the location and scale estimates of the groups. The first section is in units of 10 3 . The second sections are in units of 10 5 . The differences and confidence intervals were standardized by the average of the estimates of each group. Only the positive mode is shown here, while the negative mode can be found in the SI Dataset S1.

if it indicates that for low molecular weight compounds, the related pathways are generally anabolic, while for high molecular weight compounds, the related pathways are generally catabolic. This is often a typical hallmark of certain diseases or stresses (Table 1). | Ŝn,A -Ŝn,B| is the magnitude of this change, which can be further standardized by dividing it by 1 2 ( Ŝn,A + Ŝn,B). Combing this magnitude with the direction, it is called a metabolic momentum of sample A and B of n molecules of interest with regards to scale. Analogously, higher-order standardized moments of the mass spectra distribution of sample A of n molecules of interest, can be denoted as kSM n,A. However, their biological significance is much weaker. For example, Pearson mode skewness is based on the difference between the mean and mode. In a metabolomics dataset, most compounds are trace amounts, meaning the mode should always be close to zero. Therefore, if the skewness increases, the location estimates should also increase in most cases. Similar logic can be deduced for the relation of kurtosis and scale. Due to the extreme heterogeneity of mass spectra data, robust statistics are recommended. In this brief report, Hodges-Lehmann estimator (H-L) [START_REF] Hodges | Estimates of location based on rank tests[END_REF] and median standard deviation (msd) [START_REF] Bickel | Descriptive statistics for nonparametric models iv[END_REF] are used. The overall picture of metabolic momentums of different classes is named as vectome (Table 2).

Results

Here, two metabolomics studies are used as examples.

The study by Yang et al. compares the plasma metabolome of ordinary convalescent patients with antibodies (CA), convalescents with rapidly faded antibodies (CO), and healthy subjects (H) [START_REF] Yang | Plasma metabolome and cytokine profile reveal glycylproline modulating antibody fading in convalescent covid-19 patients[END_REF]. For both CA and CO, purine-related metabolism significantly towards anabolism and duobolism compared to the healthy volunteers (Table 2), aligned with a previous study that showed purine metabolism is significantly up-regulated after SARS-CoV-2 infection [START_REF] Xiao | Integrated cytokine and metabolite analysis reveals immunometabolic reprogramming in covid-19 patients with therapeutic implications[END_REF]. Acylcarnitinerelated pathways exhibit a significant inclination towards catabolism and centrabolism (Table 2). This conclusion, which does not require knowledge of individual compounds within the acylcarnitine class, was also emphasized by Yang et al. [START_REF] Yang | Plasma metabolome and cytokine profile reveal glycylproline modulating antibody fading in convalescent covid-19 patients[END_REF]. It was observed that long-chain acylcarnitines were generally lower in both convalescent groups, while medium-chain acylcarnitines displayed the opposite pattern [START_REF] Yang | Plasma metabolome and cytokine profile reveal glycylproline modulating antibody fading in convalescent covid-19 patients[END_REF]. Bile acid-related pathways leaned towards anabolism and duobolism in CA group, while bile acids have been reported to be immunomodulatory [START_REF] Kong | Roles of bile acids in enteric virus replication[END_REF][START_REF] Visekruna | The role of short-chain fatty acids and bile acids in intestinal and liver function, inflammation, and carcinogenesis[END_REF]. Organooxygen compounds-related pathways leaned towards catabolism in both convalescent groups. The only accurately annotated compound in this class is kynurenine. This aligns with a previous study that found the kynurenine pathway, which is the primary catabolic pathway of tryptophan, is significantly up-regulated in COVID-19 patients [START_REF] Cai | Kynurenic acid may underlie sex-specific immune responses to covid-19[END_REF][START_REF] Cihan | Kynurenine pathway in coronavirus disease (covid-19): Potential role in prognosis[END_REF]. For both CA and CO, metabolism related to carbohydrates significantly shifts towards anabolism and duabolism compared to that of healthy volunteers (Table 2). This might be due to the dysregulated glucose metabolism [START_REF] Ac Codo | Elevated glucose levels favor sars-cov-2 infection and monocyte response through a hif-1alphaglycolysis-dependent axis[END_REF][START_REF] Khunti | Covid-19, hyperglycemia, and new-onset diabetes[END_REF]. Because the mass-weighted intensity distribution is the product of the concentration of the molecules and their mass, if the mass shrinks to half during a reaction but the concentration doubles, the location of the mass-weighted intensity distribution should generally remain the same. In addition, many intermediates in the glycolytic pathway have higher molecular weights than glucose, e.g., glucose-6-phosphate. Therefore, the breakdown of glucose (C6H12O6) into two molecules of pyruvate (C3H4O3) theoretically should increase the location of the mass-weighted intensity distribution. This is a limitation of metabolic momentums as they can only accurately reflect the directions of chemical reactions that have two or more distinct major compounds as substrates or products.

Ding et al. created a comprehensive metabolome atlas for the wild-type mouse brain [START_REF] Ding | A metabolome atlas of the aging mouse brain[END_REF]. Table 1 shows the result of using hydrophilic interaction chromatography (HILIC) to seperate compounds, mainly for amines. During the aging process, in HILIC datasets, mouse brain metabolism generally shifts towards catabolism and centrabolism. This supports their conclusion that the structural degradation of brain matter becomes more pronounced in older age groups, accompanied by increased protein breakdown and elevated levels of amino acids, dipeptides, and tripeptides [START_REF] Ding | A metabolome atlas of the aging mouse brain[END_REF].

Table 1 . Descriptive statistics of the mass-weighted intensity distributions of Ding et al.'s HILIC-MS dataset

 1

	Age	Sex	H-L	msd	Comparisons	S_Diff_H-L	S_Diff_H-L_CI	S_Diff_msd	S_Diff_msd_CI
	3 weeks	Male	649.82	564.73	3w:Female-Male	0.00	(-0.06,0.05)	0.00	(-0.06,0.06)
	59 weeks	Male	580.80	524.53	Male:3w-59w	0.11	(0.06,0.17)	0.07	(0.01,0.13)
	3 weeks	Female	647.80	565.22	59w:Female-Male	0.03	(-0.02,0.08)	0.01	(-0.04,0.07)
	59 weeks	Female	600.23	531.98	Female:3w-59w	0.08	(0.02,0.13)	0.06	(0.00,0.10)

  sample B contains more low-weight molecules compared to sample A, it is considered that sample B exhibits a catabolic direction compared to sample A with regards to n molecules of interest, the location estimate Ln,B is expected to decrease, i.e., Ln,A > Ln,B. Conversely, sample A exhibits an anabolic direction compared to sample B. This provides a mathematical definition for two classic metabolic directions. The absolute difference of Ln,A and Ln,B is the magnitude of this change. This magnitude can be further standardized by dividing it by

1 2 ( Ln,A + Ln,B). Combing this magnitude with the direction, it is called a metabolic momentum of sample A and B of n molecules of interest with regards to location. Then, further consider a scale estimate of C1,n,AC2,n,A, denoted as Ŝn,A. If Ŝn,A > Ŝn,B, i.e., there is a significant decrease in the scale estimates, the metabolic direction of sample B is considered centrabolic compared to sample A for n molecules of interest. Conversely, sample A is considered duobolic compared to sample B for n molecules of interest. This mathematical approach reveals two new metabolic directions, which have clear biological significance. If the metabolic direction of a sample of n molecules of interest is centrabolic compared to that of another sample of the same n molecules of interest,

To whom correspondence should be addressed. E-mail: tl@biomathematics.org www.pnas.org/cgi/doi/10.1073/pnas.XXXXXXXXXX PNAS | February 14,

| vol. XXX | no. XX | 1-3

| www.pnas.org/cgi/doi/10.1073/pnas.XXXXXXXXXX Li

Data and Software Availability

All data are included in the brief report and SI Dataset S1. All codes have been deposited in GitHub.


Elena Gissi
email: elena.gissi@ismar.cnr.it

Frank Maes

Zacharoula Kyriazi

Ana Ruiz-Frau

Catarina Frazão Santos

Barbara Neumann

Adriano Quintela

Fátima L Alves

Simone Borg

Wenting Chen

Maria Da

Luz Fernandes

Maria Hadjimichael

Elisabetta Manea

Márcia Marques

Froukje Maria Platjouw

Michelle E Portman

Lisa P Sousa

Luca Bolognini

Wesley Flannery

Fabio Grati

Cristina Pita

Natașa Văidianu

Robert Stojanov

Jan Van Tatenhove

Fiorenza Micheli

Anna-Katharina Hornidge

Sebastian Unger

R Ania

Contributions of marine area-based management tools to the UN sustainable development goals

Keywords: area-based management, marine/maritime spatial planning, ocean governance, cooperation mechanisms, areas beyond national jurisdiction, biodiversity, conservation, sustainable development

à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

The United Nations (UN) 2030 Agenda for Sustainable Development (United Nations, 2015), henceforth the 2030 Ag nda i a h i ti in u i and h nt t at gy n pa ing a t f 1 "int g at d and indi i ib " u tainab D p nt G a ( DG ). On f th g a DG 14 Life below water, focuses specifically on the conservation and sustainable use of the ocean and its resources. It builds on commitments and requirements as set out in different, yet related legal instruments or international declarations. For example, the target to conserve at least 10% of coastal and marine areas by 2020 (SDG 14.5) was based on the UN Convention on Biological Diversity (CBD) Aichi Target 11 (Convention on Biological Diversity, 2010). Th 'z d aft' p p a f th BD p t-2020 global biodiversity framework now recommends the protection of at least 30% of the ocean by 2030 (UNEP, 2020). Achieving conservation outcomes in the ocean while supporting other DG i iti a p ia y in ight f th nt and apid "b u " a ati n in marine resource exploitation [START_REF] Jouffray | The Blue Acceleration: The Trajectory of Human Expansion into the Ocean[END_REF], and major challenges in achieving sustainable blue growth [START_REF] Laffoley | Evolving the narrative for protecting a rapidly changing ocean, post-COVID-19[END_REF]Rilov et al., 2020a;[START_REF] Winther | Integrated ocean management for a sustainable ocean economy[END_REF]. Furthermore, the ocean is a continuum, with currents and species moving across multiple zones [START_REF] Popova | Ecological connectivity between the areas beyond national jurisdiction and coastal waters: Safeguarding interests of coastal communities in developing countries[END_REF] and ecosystems being affected by transboundary anthropogenic pressures that cannot be controlled through protected zones alone [START_REF] Menegon | A modelling framework for MSP-oriented cumulative effects assessment[END_REF][START_REF] Reusch | The Baltic Sea as a time machine for the future coastal ocean[END_REF]. Whilst there is a growing body of literature on the nature of interlinkages between sustainability goals and targets in the ocean [START_REF] Nash | To Achieve a Sustainable Blue Future, Progress Assessments Must Include Interdependencies between the Sustainable Development Goals[END_REF][START_REF] Nilsson | Policy: Map the interactions between Sustainable Development Goals[END_REF][START_REF] Obura | Getting to 2030 -Scaling effort to ambition through a narrative model of the SDGs[END_REF]S. Schmidt et al., 2017;[START_REF] Singh | A rapid assessment of co-benefits and trade-offs among Sustainable Development Goals[END_REF], there is limited comprehensive evaluation of the contribution of specific management tools to attaining SDGs.

Area-based management tools (ABMTs) are globally applied, purpose-orientated instruments used in the planning and management of marine and coastal areas. By definition, ABMTs entail the implementation of a system of rights and duties in a particular management area, under the responsibility of a designated authority, and tend to afford high levels of protection [START_REF] Roberts | Area-based management on the high seas: Possible application of th I O' pa ti u a y n iti a a a oncept[END_REF][START_REF] Unga | Report of the Secretary-General of the United Nations General Assembly on Oceans and the Law of the Sea (10 September 2007)[END_REF]. Taking into account the legal status of the different maritime zones under the UN Convention on the Law of the Sea (UNCLOS), ABMTs range from sectoral spatial instruments designed to manage a particular human activity (e.g., fisheries, shipping, or mining) to cross-sectoral tools for managing multiple uses, such as marine protected areas (MPAs), and marine/maritime spatial planning (MSP) [START_REF] Gottlieb | Area Based Management Tools, Including Marine Protected Areas in Areas Beyond National Jurisdiction: A Report of the workshop on Area Based Management Tools, including Marine Protected Areas in Areas Beyond National Jurisdiction[END_REF].

These tools reached particular global resonance in recent years, as part of biodiversity conservation targets and the negotiation of an international legally binding instrument (under UNCLOS) for the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ) (General Assembly resolution 72/249, United Nations, 2018). In addition to being discussed as a potential measure to achieve BBNJ-related objectives, ABMTs have been identified as a key mechanism for delivering global biodiversity goals and SDG 14 [START_REF] Reimer | Benefits and gaps in area-based management tools for the ocean Sustainable Development Goal[END_REF]. However, due to the great variety of ABMTs, there is a need for a clear understanding of how these tools can contributeseparately and/or combinedto the implementation of the 2030 Agenda as a whole. Given the indivisible and interlinked nature of SDGs delivering on a broad range of objectives, it is vital that implementation considers synergies and trade-offs between different SDGs. Understanding the broad and interconnected nature of SDGs is key to supporting decision-makers, managers and communities in applying ABMTs to maximize policy effectiveness for environmental and societal benefits, as well as addressing challenges and potential trade-offs among goals.

Here, we review existing types of ABMTs as stipulated by different international and regional agreements (Fig. 1) and their contribution to achieving SDG 14 and other SDGs. Drawing on expert opinion, we first assessed th p t ntia ang f AB T ' nt ibuti n t a hi ing th diff nt ta g t f SDG 14, together with several other interlinked SDGs with strong implications for ocean-related transformations towards sustainability, i.e., SDGs 1, 2, 5, 7-13, 16, and 17 (see section 2.2 below). We then explored constraining and enabling factors of ABMTs implementation through existing cases and evidence from literature. Finally, we discussed the potential multiple contributions of ABMTs to sustainable development in both areas beyond national jurisdiction (ABNJ) and areas under national jurisdiction, and we outlined pathways towards more effective SDGs achievementacknowledging the multiplicity of social, environmental, economic, political, and institutional challenges, as well as opportunities that come with ABMTs implementation.

Material and methods

The assessment conducted in this study is structured around two main steps: i) the descriptive analysis of a vast set of ABMTs with respect to their scope, mandate, responsibilities, spatial extent, and single/multiple sector-based objectives; and ii) the qualitative assessment of the potential contribution of selected ABMTs to ocean-related SDGs of the 2030 Agenda.

Descriptive analysis of ABMTs (Step 1)

An initial list of 47 ocean-related international agreements (at global and regional levels) was compiled, with respect to shipping, fisheries management, deep seabed mining in the Area, underwater natural and cultural heritage, environmental conservation, and marine spatial planning (Step 1). We screened them and compiled a list of ABMTs mentioned by the respective legal sources and related tools. ABMTs were selected along two criteria: i) implementation in practice; and ii) existing specific, identifiable geographical scope for zoning. We recorded how legal sources at the international level have shaped ABMTs with regard to spatial scope, mandate and responsibilities, and single/multiple sector-based objectives (protocol in Table A.1).

ABMTs were analyzed (Table A.2) with respect to: i) their objectives; ii) authorities responsible for delivering such objectives; iii) the system of management and planning entailed in the ABMT forms; and iv) the specific spatial domain ABMTs refer to (both vertical depth and horizontal).

We grouped ABMTs according to the focus/sector of each tool into six categories based on Muraki Gottlieb et al. ( 2018) (Table A.3): i) fishery-related ABMTs; ii) shipping-related ABMTs; iii) ABMTs related to deep seabed mining in the Area; iv) ABMTs related to underwater cultural and natural heritage (UCNH); v) conservation-related ABMTs; vi) MSP initiatives. These categories were further used to perform a qualitative assessment of ABMTs as described below (Step 2). The full list of ABMTs and the analysis from the related legal sources is reported in a database attached to this study.

Contribution of ABMTs towards SDGs (Step 2)

After identifying, analyzing, and grouping ABMTs (Step 1), we selected the SDGs on which to focus the analysis (the SDGs selection procedure is described in the Supplementary methods A.4. We then assessed the contribution of the previously identified ABMTs towards the selected SDGs through expert elicitation.

Subsequently, we added elements of existing ABMTs implementation, based on evidence from the literature.

We focused on SDG 14 Life below water (United Nations, 2020) and its main targets (14.1 to 14.7), as well as on other ocean-related SDGs, at the goal level. (Reimer et al. 2020), which we aim to expand here. With respect to SDG 14, we focused the analysis on the seven outcome-oriented targets (targets 1-7). We did not address the three targets (targets a-c) that represent " an f i p ntati n" (na y i n and t hn gy kn w dg -sharing and capacity building, and implementation of international law) as the latter were recognized to be inconsistently formulated and mainly qualitative [START_REF] Bartram | Policy review of the means of implementation targets and indicators for the sustainable development goal for water and sanitation[END_REF].

The assessment of the contribution of each ABMT to the SDGs took place according to the protocol reported in Table 1. The scoring framework developed by [START_REF] Nilsson | Policy: Map the interactions between Sustainable Development Goals[END_REF] and applied by [START_REF] Nilsson | A Guide to SDG Interactions: from Science to Implementation[END_REF],

by [START_REF] Mccollum | Connecting the sustainable development goals by their energy inter-linkages[END_REF], and by Schmidt et al. (2017) specifically on the case of SDG 14, was applied to assess the contributions of ABMTs to SDG 14 at the target level, and for the other selected SDGs at the goal level. The framework (Table 2) employed a seven-point rating scale to identify benefits and trade-offs between ABMTs and SDGs. It allowed a rapid assessment of relationships among them and highlights priorities for integrated policy. As the potential contribution of ABMTs towards SDGs is independent from its application in a specific maritime domain, the assessment of these contribution was conducted jointly for areas under national jurisdictions and ABNJ. Table 2: Qualitative scoring system to assess the contribution of the ABMT to the achievement of the SDGs, elaborated from [START_REF] Nilsson | A Guide to SDG Interactions: from Science to Implementation[END_REF][START_REF] Nilsson | Policy: Map the interactions between Sustainable Development Goals[END_REF] and [START_REF] Singh | A rapid assessment of co-benefits and trade-offs among Sustainable Development Goals[END_REF].

Score Name of the criterion Explanation expanded from Nilsson et. al (2016) for the purpose of this study

Example of assessed relationships between ABMTs and SDG goals for illustration (this study)

Benefits (potential positive contribution of the ABMT to the achievement of the target or goal)

+3 Indivisible

Goal achievement is inextricably linked with the designation and implementation of the ABMT.

The achievement of SDG target 14.5 which aims to conserve at least 10% of coastal and marine areas is inextricably linked to the implementation of MPAs.

+2

Reinforcing Goal achievement is reinforced by the designation and implementation of the ABMT (direct support).

MSP is a reinforcing condition to SDG target 14.2, i.e. the sustainable management and protection of marine and coastal ecosystems.

+1 Enabling

The designation and implementation of the ABMT creates conditions that further the goal (indirect support).

The designation and implementation of shippingrelated ABMTs can reduce potential harm from international shipping to marine and coastal ecosystems providing multiple benefits and natural resources (ie ecosystem services) to coastal communities, indeed enabling SDG 1 No poverty achievement.

Neutral contribution of the ABMT to the target or goal 0 Neutral No significant positive or negative interactions towards goal achievement.

The designation of an APEI by the International Seabed Authority or the development of environmental management plans for defined areas such as the Clarion Clipperton Zone have no apparent positive or negative interaction with SDG target 14.6 which is related to the prohibition of certain fisheries subsidies.

Trade-offs (potential negative contribution of the ABMT to the achievement of the target or goal)

- (Ghent, 20-21 February 2019), where they were trained on the assessment method. The sub-teams were composed of at least three researchers coordinated by the lead author. They worked through small-group discussions to reach agreement on each score, first in person during the workshop, and remotely afterwards. The sub-teams were also asked to assess the confidence (Table 1) with which they collectively judged the different potential contributions of ABMTs towards the achievement of SDGs. Confidence scores were assigned considering the level of expert knowledge on the different ABMTs.

Once the scoring was defined, the sub-teams also analyzed the actual implementation of ABMTs, reporting evidence on potential enabling factors and barriers that enhance or inhibit ABMTs contribution towards specific SDGs. The sub-teams leveraged evidence from their own knowledge, as well as scientific and grey literature on the implementation of ABMTs. They compiled empirical examples and cases of ABMT implementation that have contributed towards (or hindered) the achievement of the targeted SDG. Finally, the sub-teams assessed the level of evidence of implemented cases, and related enabling or constraining factors, in order to identify potential knowledge gaps in our assessment.

When preliminary versions of the assessment for all ABMTs were finalized, they were circulated among the entire group of authors with two goals: i) provide elements of agreement or disagreement with the initial assessment; ii) comment and add potentially relevant knowledge and cases on the implementation of ABMTs. The sub-teams were then asked to collect feedback and to elaborate on potential points of disagreement in the assessments.

Finally, revised versions of the assessment were circulated among the entire expert group again, and further discussed in a second expert workshop (Potsdam, 10-11 December 2019). Here, there was a special focus on points of disagreement regarding the scoring through verbal discussions in parallel and plenary sessions. The final version of the assessment was jointly consolidated into 20 SDG-ABMT tables (see Tables B.1-20).

Results

ABMTs contributions to ocean sustainability goals

ABMTs have the potential to generate multiple benefits necessary for achieving SDG 14 and other oceanrelated SDGs (Figs. 2 and3; for a detailed description see Tables B.1-20). For SDG 14, Figure 2 indicates that fisheries-and conservation-related ABMTs, and MSP have the greatest potential contributions overall.

Also, looking at the columns, there is high complementarity and synergy among different ABMTs for most targets, with the exception of SDG 14.6 Prohibit fisheries subsidies. These patterns are also evident in Figure 3 for the other SDGs, for which fishery-and conservation-related ABMTs, and MSP have the greatest potential contributions overall, with high complementarity for most goals, and the lowest in SDG 7

Affordable and clean energy.

While some of these contributions are straightforward, others are nuanced or unexpected. Indeed, some AB T a in xt i ab y ink d t th a hi nt f p ifi DG 14 ta g t b ing "indi i ib " f th (Fig. 2 and3). For instance, SDG target 14.5 relates to the conservation of at least 10% of coastal and marine areas and is thus inextricably linked to the current global coverage of MPAs (United Nations, 2015).

Similarly, fishery-related ABMTs aim to regulate harvesting to avoid overfishing, eliminate illegal unregulated and unreported fishing, and conserve living marine resources [START_REF] Haas | Explicit targets and cooperation: regional fisheries management organizations and the sustainable development goals[END_REF], thus contributing substantially to the achievement of SDG target 14.4 (Fig. 2). At the same time, there are cases where ABMTs can still create the conditions to further such goals, i.e.

" nab ing" n aiding (" inf ing") in th i a hi nt a th ugh th y a n t in xt i ab y ink d t the respective SDGs (Figs. 2 and3). Areas (Annexes I, II, IV, V) in the Baltic Sea has led to the creation of reception facilities in Baltic ports [START_REF] Klopott | The Baltic Sea as a model region for green ports and maritime transport[END_REF], followed by other EU ports in a Special Area. To meet the new environmental regulations targets, shipping industry and port facilities responded through fleet renewals and retrofitting [START_REF] Klopott | The Baltic Sea as a model region for green ports and maritime transport[END_REF]. Also, the designation of shipping-related ABMTs (e.g., Particularly Sensitive Sea Areas -PSSAs, special areas, or routing measures) contributes to sustainable tourism (SDG 8 Decent work and economic growth) by reducing safety risks and significant negative impacts of shipping, as in the Malaysia PSSA case (Marine Environment Protection Committee, 2017). Finally, transboundary protected areas, some particularly connotated peace parks, have been designated to simultaneously protect and maintain biological diversity and natural and cultural resources, and to promote peace and cooperation between countries, as in the case of the Red Sea Marine Peace Park [START_REF] Portman | Remembering the Red Sea Marine Peace Park[END_REF]; these clearly contribute to SDG 14 and SDG 16 Promote peaceful and inclusive societies for sustainable development.

In general, ABMTs have the overarching potential to contribute to SDG 17 Strengthen the means of implementation and revitalize the global partnership for sustainable development, as their designation and implementation is usually the outcome of negotiations and coordination between multiple stakeholders including private actors, non-governmental organizations and States.

Importantly, several ABMTs can significantly contribute towards SDG 13 Taking urgent action to combat climate change and its impacts, and to minimize and address the impacts of ocean acidification (SDG target 14.3). For instance, the adaptive management of fishery closures and spatially-based rights towards climateinduced shifts of fish stocks can promote long-term resource stewardship [START_REF] Ojea | Fisheries regulatory regimes and resilience to climate change[END_REF][START_REF] Pinsky | Fishing, fast growth and climate variability increase the risk of collapse[END_REF]. Targeting climate refugia to identify new MPAs is also a promising action to improve ecosystem resilience and to adapt to the effects of climate change (Rilov et al., 2020b). Another example is the proposed 10% speed reduction across the global shipping fleet to be implemented throughout shippingrelated ABMTs by the International Maritime Organization (IMO), which is estimated to reduce overall greenhouse gas emissions (GHG) by around 13% [START_REF] Faber | Regulating speed: a short-term measure to reduce maritime GHG emissions[END_REF][START_REF] Psaraftis | Speed optimization vs speed reduction: The choice between speed limits and a Bunker Levy[END_REF], and therefore improves the probability of meeting GHG reduction targets by 23% [START_REF] Comer | Relating short-t a u t I O ' minimum 2050 emissions reduction target[END_REF]. The OSPAR Commission for the Protection of the Marine Environment of the North-East Atlantic Ocean and the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) emphasize the importance of marine research on ocean acidification to ensure effective management of their MPA networks [START_REF] Johnson | Climate change is likely to severely limit the effectiveness of deep-sea ABMTs in the North Atlantic[END_REF], in line with the indications of SDG target 14.3 on minimizing and address the impacts of ocean acidification, including through enhanced scientific cooperation at all levels.

For several SDGs, limited evidence was found on the potential contributions of ABMTs towards their achievement. This is the case, for example, of SDG 14.6 Prohibit certain forms of fisheries subsidies which contribute to overcapacity and overfishing, where no clear contribution was detected for any ABMTs, except for fishery-related ones. This is most likely due to the limited spatial nature of the target for which the other ABMTs are not suitable instruments. Negative influences of ABMTs on SDG 14 targets and other goals were not identified.

Enabling factors and impediments to progress towards SDGs

Although it is clear that ABMTs have the potential to contribute substantially to the achievement of SDGs, there are important factors that could reduce or potentially even hinder the realization of such contributions.

To unlock the full potential of ABMTs for SDG achievement, it is therefore crucial to consider a range of context-specific, positive and negative factors (see examples in Table 3, and full description in Tables B.1-20). Though the evidence is still limited for several ABMTs (Figs. 4 and5), overall enabling factors and impediments were found to be largely related to questions of governance (e.g., in conservation-oriented ABMTs [START_REF] Ban | Social and ecological effectiveness of large marine protected areas[END_REF][START_REF] Sciberras | Evaluating the relative conservation value of fully and partially protected marine areas[END_REF]), institutional capacity in ABMTs enforcement (e.g., in fishery-related ABMTs in ABNJ [START_REF] Haas | Factors influencing the performance of regional fisheries management organizations[END_REF]), societal challenges (e.g. raising awareness amongst multiple actor groups, such as on cultural and natural heritage along with UCNH sites implementation [START_REF] Calado | Multi-uses in the Eastern Atlantic: Building bridges in maritime space[END_REF]), or environmental factors (e.g. with regard to the effectiveness of fishery closures both in areas under national jurisdiction [START_REF] Beare | Evaluating the effect of fishery closures: Lessons learnt from the Plaice Box[END_REF] and ABNJ [START_REF] Davies | Use of a counterfactual approach to evaluate the effect of area closures on fishing location in a tropical tuna fishery[END_REF]).

For instance, a complex picture emerged on whether or not MPA designation and implementation increases p p ' a f d u ity ( DG 2) a th nab ing fa t f i p nting PA t wa d f d security are unclear [START_REF] Charles | Fishing livelihoods as key to marine protected areas: insights from the World Parks Congress[END_REF][START_REF] Kumar | Sustainable Management of Fisheries and Aquaculture for Food Security and Nutrition: Policies Requirements and Actions[END_REF]. Moreover, the impact of MPAs on food security and health of local populations is complicated by a range of mediating, historical, political, socioeconomic, ecological, seasonal, cultural, and contextual factors [START_REF] Kamat | Food insecurity and coping strategies in a marine protected area in southeastern Tanzania[END_REF]. Similarly, the likelihood of reducing impacts from deep sea trawling on seabed habitats and biota by fisheries spatial measures is influenced by several factors. These range from legal barriers, to the characteristics of the fishery and the ecosystem, to local, regional or national priorities and resources [START_REF] Mcconnaughey | Choosing best practices for managing impacts of trawl fishing on seabed habitats and biota[END_REF], thus affecting the contribution of fishery-related ABMTs towards SDG targets 14.2, 14.4, and 14.5. Enforcement capacity of ABMTs also determines the contribution towards SDGs. Adequate human and financial resources to implement ABMTs have proven critical for MPAs within national jurisdiction and in ABNJ [START_REF] Gill | Capacity shortfalls hinder the performance of marine protected areas globally[END_REF], as well as for fishery closures [START_REF] Haas | Factors influencing the performance of regional fisheries management organizations[END_REF] and UCNH zones [START_REF] Calado | Multi-uses in the Eastern Atlantic: Building bridges in maritime space[END_REF].

For example, mobilizing private investments by setting up innovative financing mechanisms is critical in supporting enforcement capacity [START_REF] Thiele | Innovative financing for the High Seas[END_REF]. [START_REF] Vivero | Food security and maritime security: A new challenge for the u p an Uni n' an p i[END_REF] found that, with the exception of the African Union and its 2050 Africa's Integrated Maritime Strategy, the notion of food security can be said to lack relevance and visibility in newest visions of marine strategy. This will influence the way the concept is formally reflected in technical and political documents (Suárez-de [START_REF] Vivero | Food security and maritime security: A new challenge for the u p an Uni n' an p i[END_REF] Heritage is slowly but peremptorily becoming a standard reference tool for underwater archaeology and underwater cultural heritage management. The many provisions included within the Convention touch on many aspects that are key to an effective protection and promotion of the underwater cultural heritage. Within the web of these provisions many aspects are gaining consideration and driving research in underwater archaeology worldwide. These provisions, when seen within a wider frame of social, economic and technological dynamics, pinpoint many aspects requiring further scrutiny from the disciplinary circle [START_REF] Secci | Survey and Recording Technologies in Italian Underwater Cultural Heritage: Research and Public Access Within the Framework of the 2001 UNESCO Convention[END_REF]. Shipping-related ABMTs and SDG 11: The designation of PSSA and the adoption of routeing measures (ATBA and TSS) in relevant areas for cultural and natural heritage contribute to their safeguard (Target 11.4) by reducing significant negative impacts of shipping. However, TSS speed reduction is not mandatory [START_REF] Faber | Regulating speed: a short-term measure to reduce maritime GHG emissions[END_REF], hampering the contribution of PSSA towards safeguarding UCNH. Fishery-related ABMTs and SDG 12: With respect to sustainable consumption, already in 2007, [START_REF] Jacquet | Funding Priorities: Big Barriers to Small-Scale Fisheries[END_REF] documented several limitations in the relationships between seafood awareness campaigns and sustainable consumption, due, for instance, to the lack of traceability of the products, and, consequently, the capacity to relate to fishery-related ABMT. Still, the proliferation of eco-labelling practices makes the assessment and evaluation of their effectiveness complex [START_REF] Alfnes | Labeling farmed seafood: A review[END_REF]. Transparency Conservation-related ABMTs and SDG 2: In five MPAs of South Africa, the loss of tenure rights and access to resources amongst already marginalized communities contributed to food insecurity, less exchange of food and less household income [START_REF] Sowman | Social impacts of marine protected areas in South Africa on coastal fishing communities[END_REF]. Nevertheless, MPAs may represent a viable strategy for enhancing food security, but current MPA practices in many places can negatively affect some fishers [START_REF] Mascia | Impacts of marine protected areas on fishing communities[END_REF]. If food security of local communities is envisaged as one of the objectives to design an MPA, this has to be clearly addressed in the MPA management and governance [START_REF] Kamat | Food insecurity and coping strategies in a marine protected area in southeastern Tanzania[END_REF]. Governance structure Conservation-related ABMTs and SDG 10: When setting a MPA, the conservation targets, the established objectives, and the type of governance structures in place will partly determine the benefits for coastal communities and their equal distribution across social groups, actors, and communities [START_REF] Bennett | Social equity and marine protected areas: Perceptions of small-scale fishermen in the Mediterranean Sea[END_REF]. Inclusivity MSP and SDG 2: In Canada, MSP supports priority use of marine resources for First Nations traditional use (subject to conservation needs), including food, social and ceremonial requirements. It also supports maintenance of natural resource systems that deliver marine goods and services at multiple scales (Pacific North Coast Integrated Management Area (PNCIMA) Initiative, 2017) Fishery-related ABMTs and SDG 8: Fishery-related ABMTs such as fishery closures have the capacity to provide both economic benefits (e.g., revenues, incomes) and conservation benefits. These benefits, however, depend on several factors [START_REF] Goetze | Demonstrating multiple benefits from periodically harvested fisheries closures[END_REF] such as the duration of the closing period; the extension of the closing area (the larger the better), compliance to the closure, which should be encouraged via community engagement and enforcement; and strict deadlines/goals for harvesting to prevent overfishing. A general hindering factor pertains to power relationships and equity in ABMTs designation and implementation, both within and between countries, with respect to the use of marine resources (SDG targets 14.2, 14.5, and 14.7). This is of special concern to Small Island Developing States and Least Developed

Countries, many of which can be affected by activities occurring beyond their national boundaries [START_REF] Popova | Ecological connectivity between the areas beyond national jurisdiction and coastal waters: Safeguarding interests of coastal communities in developing countries[END_REF]. Concerns for equity in designating ABMTs are particularly relevant in marine areas under national jurisdiction, for instance with respect to equal access to natural resources for multiple economic actors and local communities [START_REF] Stead | Rethinking marine resource governance for the United Nations Sustainable Development Goals[END_REF]. Concerns on equity and power relationships have also been raised on ABNJ for deep seabed mining, e.g., with regard to Areas of Particular Environmental Interest (APEIs), and on fishery closures. For these areas, transparency and inclusiveness are at stake for decisionmaking mechanisms of the International Seabed Authority [START_REF] Ardron | Incorporating transparency into the governance of deepseabed mining in the Area beyond national jurisdiction[END_REF] and some of the Regional Fishery Management Organizations (RFMOs) [START_REF] Haas | Factors influencing the performance of regional fisheries management organizations[END_REF].

Discussion

This study showed that ABMTs can significantly contribute to SDGs attainment, with fisheries-and conservation-related ABMTs, and MSP having the greatest potential contributions overall. We also depicted various ways in which ABMTs can complement the attainment of various SDGs in parallel, showing high complementarity and synergy among different ABMTs for most SDGs.

Importantly, we did not find trade-offs between ABMTs and SDGs. This might be partially attributed to the methodological approach taken in this research, which focused on potential contributions of ABMTs for achieving SDGs under ideal circumstances. Further in-depth analysis of existing cases that accounts for different context-related factors would be valuable to show how the contribution of ABMTs to achieving SDGs is dependent on case-based implementation. This is also valid for the ABMTs for which we did not find any apparent contribution towards some SDGs, such as for shipping-related ABMTs towards SDG 5 on Gender equity. In these cases, the authors were not aware of any case of ABMT implemented for the purpose of achieving other SDGs in addition to their primary purpose. This consideration opens for a vast field of investigation. For instance, intersectional research could provide valuable insights on the contributions of ABMTs towards the achievement of SDGs 3 Good health and well-being, 5 Gender equity, 10 Reduce inequalities, and on the role of multiple interacting factors shaping marine and coastal social-ecological systems, such as socio-economics, gendered division of labour, ethnicity, education level. This would help to unveil the potential contribution of ABMTs to the achievement of all the SDGs, including for those that appear not strictly related to ABMTs designation and implementation.

Another point to be raised pertains to the questions how the contributions of ABMTs towards the SDGs could be determined and monitored for best possible outcomes. The current SDG framework addresses ABMTs and their potential to achieve the SDGs in a generic way, with only two targets directly referencing ABMTs: SDG targets 14.2 and 14.5 f p ti y t " u tainab y anag [ing] Thus, a next step should be to define quantitative and qualitative indicators to monitor the contribution of ABMT implementation to achieving the SDGs. These indicators need to be relevant and straightforward [START_REF] Cai | Match words with deeds: Curbing water risk with the Sustainable Development Goal 6 index[END_REF][START_REF] Hák | u tainab D p nt G a : A need for relevant indicators[END_REF] in reflecting on the management quality towards SDG attainment, and go beyond monitoring managed areas by quantity or area coverage [START_REF] De Santo | Missing marine protected area (MPA) targets: How the push for quantity over quality undermines sustainability and social justice[END_REF][START_REF] Grorud-Colvert | The MPA Guide: A framework to achieve global goals for the ocean[END_REF]. The vast experience and knowledge on assessing MPA effectiveness towards environmental, social, and economic outcomes (e.g., [START_REF] Grorud-Colvert | The MPA Guide: A framework to achieve global goals for the ocean[END_REF][START_REF] Meehan | How far have we come? A review of MPA network performance indicators in reaching qualitative elements of Aichi Target 11[END_REF][START_REF] Picone | Marine protected areas overall success evaluation (MOSE): A novel integrated framework for assessing management performance and social-ecological benefits of MPAs[END_REF]) could be utilized to develop such indicators for assessing the contribution and effectiveness of ABMTs towards SDG achievements. A meaningful assessment framework that brings together these indicators could help to align policies and ABMT initiatives, monitor goal attainment and identify gaps, and so help making progress towards the 2030 Agenda while ensuring durable and equitable outcomes from ABMT implementation.

To make progress towards multiple SDGs at once, it is crucial to ensure coordination between initiatives established by different organisations and responsible authorities. At present, different ABMT initiatives can potentially be developed in parallel and independently from one another in the same geographical area by the respective responsible authorities, and without any coordination between the competent management bodies.

The lack of coordination between ABMTs can potentially undermine the achievement of their objectives, because of potentially conflicting visions and agendas between institutions [START_REF] Singh | A rapid assessment of co-benefits and trade-offs among Sustainable Development Goals[END_REF]. Without coordination, the co-occurrence of multiple interests and responsible authorities over the same areas can significantly hinder a holistic approach to ecosystem-based decision-making and transformation towards sustainability [START_REF] Gjerde | Towards Ecosystem-based Management of the Global Ocean: Strengthening Regional Cooperation through a New Agreement for the Conservation and Sustainable Use of Marine Biodiversity in Areas Beyond National Jurisdiction. STRONG High Seas Project[END_REF][START_REF] Saunders | Examining the role of integration in marine spatial planning: Towards an analytical framework to understand challenges in diverse settings[END_REF][START_REF] Vince | Effective integration and integrative capacity in marine spatial planning[END_REF] and hence, towards SDGs achievement. Eventually, the implementation of ABMTs can provide nuanced contributions to SDGs while responding directly to the specifics of problems they were set up to address, e.g., related to a single sector, a single area, or a single management problem.

Whereas sectoral ABMTs have the potential to directly support the implementation of specific SDG 14 targets, the analysis has shown that ABMTs taking a cross-or multi-sectoral approach tend to simultaneously enable a broader range of benefits for different SDG 14 targets, as well as for other SDGs (Fig. 1, 2). Crosssectoral ABMTs, such as MSP, are those managed to coordinate multiple uses at sea towards the common overarching objective of sustainable development [START_REF] Ehler | Marine Spatial Planning: A Step-by-step Approach toward Ecosystem-based Management[END_REF]IOC-UNESCO and DG MARE, 2017). They usually work by harmonizing sectoral management and related ABMTs through the cooperation of respective responsible authorities (e.g., fisheries agencies and conservation agencies).

Especially in Africa, initiatives to foster a blue economy are seen as a way to alleviate poverty (SDG 1) and to support sustainable economic development (SDG 8, e.g., World Bank and UNDESA, 2017). In addition to MSP, other ABMTs can adopt cross-sectoral management approaches, as it is the case of MPAs (Muraki [START_REF] Gottlieb | Area Based Management Tools, Including Marine Protected Areas in Areas Beyond National Jurisdiction: A Report of the workshop on Area Based Management Tools, including Marine Protected Areas in Areas Beyond National Jurisdiction[END_REF]. However, MSP can provide several benefits for both conservation and the sustainable use of marine resources [START_REF] Agardy | Mind the gap: Addressing the shortcomings of marine protected areas through large scale marine spatial planning[END_REF][START_REF] Fraschetti | Light and shade in marine conservation across European and contiguous seas[END_REF]Rilov et al., 2020b). MSP is usually applied to large areas under the responsibility of coastal States, i.e. territorial seas and EEZs, and so MSP can support the achievement of multiple SDGs on large areas. In some cases, national MSP initiatives fully or partially coincide with the management of large MPAs, such as in Palau with the Palau National Marine Sanctuary (PICRC and COS, 2019), and in the 30 year-long MSP process of managing the long-term p t ti n and gi a y u tainab u f Au t a ia' G at Ba i R f a in Pa k [START_REF] Day | Marine zoning revisited: How decades of zoning the Great Barrier Reef has evolved as an effective spatial planning approach for marine ecosystem-based management[END_REF].

The need for coordination of multiple ABMT initiatives for the purpose of achieving multiple SDGs is especially urgent in ABNJ, where ABMTs are generally far less developed compared to those in national waters that are subject to the rights and obligations of single coastal States, and where the coexistence of many different sectorial organizations can undermine each other. The need for MSP in international waters has long been advocated [START_REF] Ardron | Marine spatial planning in the high seas[END_REF]; Secretariat of the Convention on Biological Diversity and the Scientific and Technical Advisory Panel and -GEF, 2012; The Aspen Institute, 2011), and is increasingly argued for as part of a more comprehensive approach to ocean sustainability [START_REF] Ehler | Two decades of progress in Marine Spatial Planning[END_REF][START_REF] Wright | Marine spatial planning in areas beyond national jurisdiction[END_REF]. However, there are no formal MSP initiatives in ABNJ, nor is there a specific policy context for it.

The ongoing negotiation of a legally-binding instrument for the conservation and sustainable use of marine relevant existing legal instruments and frameworks and relevant global, regional, and sectoral bodies in ABNJ it wi b i p tant that a "na w" int pretation of this provision will be avoided in the negotiation process [START_REF] Clark | Institutional arrangements for the new BBNJ agreement: Moving beyond global, regional, and hybrid[END_REF]Scanlon, 2018). Instead, sectoral organisations with mandates in ABNJ, such as the ISA or RFMOs, need to adopt coordinated and collaborative approaches that contribute towards the overall objective of the new legal instrument. In ABNJ, there are pioneering cases of ABMT applications that have successfully provided multiple benefits towards the achievement of SDGs. An example of cross-sectoral cooperation is the development of a regional network of MPAs in ABNJ in the North-East Atlantic. This world' fi t PA n tw k in ABNJ wa tab i h d by th O PAR i i n and a g y p nd t fisheries closure in the same area established by the North-East Atlantic Fisheries Commission [START_REF] Smith | MPAs in ABNJ: lessons from two high seas regimes[END_REF]. A collective arrangement between both organisation helps further cooperation across institutional and sectoral barriers and addresses some of the weaknesses of the fragmented governance approach [START_REF] Kvalvik | Managing institutional overlap in the protection of marine ecosystems on the high seas. The case of the North East Atlantic[END_REF][START_REF] Neafc | The Process of Forming a Cooperative Mechanism Between NEAFC and OSPAR[END_REF].

Conclusions

This study demonstrates the benefits of ABMTs for the implementation of the 2030 Agenda and achieving To increase the opportunities to achieve the 2030 Agenda and associated SDGs, coastal states should address relevant contextual factors and strengthen the coordinated, equitable and inclusive applications of ABMTs.

There is an urgent need to move beyond the current sectoral approach in ABMTs, and to advance strategies and governance arrangements for coordinated actions between multiple types of ABMTs. In contrast to a sectoral ABMT approach, the adoption of a holistic perspective that promotes the coordinated and coherent implementation of ABMTs will amplify associated co-benefits for multiple SDGs, both within and beyond national jurisdiction.

Overcoming potential conflicts and competing interests that hinder the achievement of the SDGs requires not only consistent coordination and cooperation between ABMT initiatives, but also the identification of overarching goals to be achieved and towards which the different ABMT initiatives can converge through multilevel governance agreements over multi-administrative boundaries and responsibilities. SDGs in itself are an attempt to provide such overarching goals to reduce potential conflicts between multiple policy objectives. Integrated ABMTs can become a key tool to operationalize and implement SDGs in the ocean.

Future research needs to establish an indicator framework for assessing and monitoring implementation and effectiveness of ABMTs and their support of SDG attainment.

Acknowledgments

Figure 1 :

 1 Figure 1: Area-based management tools (ABMTs) identified in international and regional conventions

Figure 2 :

 2 Figure 2: Potential contribution of existing Area Based Management Tools (ABMTs) stipulated in

Figure 3 :

 3 Figure 3: Potential contribution of existing Area Based Management Tools (ABMTs) stipulated in

  d and a ti n in th establishment of fishery-related ABMTs can increase women empowerment and provide social and economic benefits to their families and the broader community (Di Ciommo and Schiavetti, 2012; Rohe et al., 2018), simultaneously supporting SDG 14.4 Regulating harvesting, SDG 5 Gender equality and SDG 1 Reduce poverty. Another example can be found with respect to SDG 9 Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation, where the adoption of MARPOL Special

Figure 4 :

 4 Figure 4: Evidence from experts' knowledge, scientific and grey literature on enabling factors and

Figure 5 :

 5 Figure 5: Evidence from experts' knowledge, scientific and grey literature on enabling factors and

  SDG 14 and other related SDGs. However, without much needed transformations in the governance of ABMTs, the largely fragmented governance of ABMTs might hamper the implementation of the holistic 2030 Agenda with its indivisible set of SDGs. Here, the 2030 Agenda might not only serve as goal-based governance framework within which ABMTs are implemented, it could also drive change that serves the development of novel holistic ocean governance approaches needed, e.g., in the context of the proposed post-2020 Global Biodiversity Framework putting forward new global targets to ensure all sea areas are under integrated biodiversity-inclusive spatial planning and at least 30 per cent globally of all sea areas are conserved through protected areas and other effective area-based conservation measures (CBD, 2021).

  th f i n " A1521 within th W king G up 2 "A a Ba d anag nt" a ti iti . W w u d ik t thank O T f th funding that made the cooperation amongst the authors, and thus this article, possible. EG partially acknowledges also funding from PORTODIMARE

  Seabed Authority ABMTs apply there). Both can be taken together as ABNJ. The colors of the rectangles represent the sector or cross-sectorial group to which the ABMTs belong. The vertical marine domain subdivisions indicate the scope of the ABMTs, such as air, water, seabed, and are shown by different icons.

	u d app y. "High a " i ju t th wat	u n in ABNJ. Th	a f	i th "A a" (International
	For detailed descriptions of each ABMT see Table A.3; APEI=Areas of Particular Environmental Interest,
	ASMA=Antarctic Specially Managed Area, ASPA=Antarctic Specially Protected Area, BBNJ=Biodiversity
	Beyond National Jurisdictions, EBSA=Ecologically and Biologically Significant Area, ECA=Emissions
	Control Areas, FRA=Fisheries Restricted Areas, GES=Good Environmental Status, MPA=Marine Protected

Maritime zones are split in areas under national jurisdiction (including the Exclusive Economic Zone) and areas beyond national jurisdiction (ABNJ), indicating in which maritime zone the ABMTs classified by the colored rectangles can Area, MSP=Marine/Maritime Spatial Planning, OECM=Other Effective area-based Conservation Measure, PA=Protected Areas, PSSA=Particular Sensitive Sea Areas, SAC=Special Areas of Conservation, SCI=Site of Community Importance, SECA=Sulphur Emissions Control Areas, SPA=Specially Protected Areas, TURF=Territorial Use Rights in Fisheries, VME=Vulnerable Marine Ecosystems; for the acronyms of the International and Regional Agreements see Table C.1.

Table 1 : Research questions and criteria for the assessment of the contribution of ABMTs towards the achievement of SDG 14 targets and other ocean related SDGs. Research question Field code Field name Description Sources

 1

	SDG 14 target or SDG	Q5.1 No. of SDG 14 target or	Number of the SDG 14 target or of the	(United
	assessed	SDG	SDG goal for which the assessment was	Nations,
			made.	2015)
		Q5.2 SDG 14 target or SDG	Text of the SDG 14 target or SDG for	(United
			which the assessment is produced.	Nations,
				2015)
	What is the potential	Q5.3 Score	Qualitative scoring that represents the	(Nilsson et
	contribution of the		potential contribution of the ABMT to the	al., 2017,
	ABMT towards the		respective SDG target or SDG goal; the	2016; Singh
	achievement of the		scoring is described in Table 3.	et al., 2018)
	respective SDG?	Q5.4 Contribution to the SDG Textual description of the potential
			contribution of the ABMTs group to the
			SDG studied.
				(Mastrandrea
				et al., 2011;
				McCollum et
				al., 2018)

What is the level of confidence on which the assessment is based?

Q5.5 Confidence

Qualitative scoring indicating the confidence level of the experts in assessing the potential contribution of ABMTs towards the SDG (summary t : ' w ' ' diu ' 'high').

Table 3 :

 3 Examples of enabling and constraining factors of the contribution of ABMTs to attaining SDGs.

	For details see Tables B.1-20.
	Categories	of	Examples
	enabling	and
	constraining
	factors
	Political		Fishery-related ABMTs and SDG 2: Suarez de Vivero et al. (Suárez-de
	factors/political
	will

  and related ABMTs. Legal factors MSP and SDG 7: By supporting the allocation of space to renewable energy developments, MSP can substantially increase the share of renewable energy in the global energy mix by 2030(European Commission, 2019). The overall legal framework for wind energy projects in ABNJ can however pose challenges. Flag states will play a central regulatory role for high seas wind energy developments. However, there is the risk that flags of convenience might unduly undercut environmental and safety standards (in place for projects at territorial sea and EEZs). Such abuse of high seas freedom could compromise the

		UN LO p in ip	f 'du ga d'.	P app a h and th	tab i h nt f	p ati	hani	d
		by the IMO, could safeguard against such potential misappropriation (Elsner and Suarez, 2019).
	Enforceability	UCNH ABMTs and SDG 9: The 2001 UNESCO Convention on the Protection of the Underwater Cultural