EUROPEAN COMMISSION Brussels, 25.6.2020 SWD(2020) 62 final COMMISSION STAFF WORKING DOCUMENT Background document for the Marine Strategy Framework Directive on the determination of good environmental status and its links to assessments and the setting of environmental targets Accompanying the Report from the Commission to the European Parliament and the Council on the implementation of the Marine Strategy Framework Directive (Directive 2008/56/EC) {COM(2020) 259 final} - {SWD(2020) 60 final} - {SWD(2020) 61 final}



Table of Contents 1.Introduction 2.General requirements of the MSFD 2.1.Main implementation stages in a six-year cycle 2.2.Geographic scope 2.2.1.Member State marine waters (Article 3(1)) 2.2.2.MSFD marine regions and subregions (Article 4) 2.3.Regional and subregional implementation (Article 5 and 6) 2.4.Integration with other EU legislation 3.Determination of good environmental status (Articles 3(5) and 9, Annexes I and III) 3.1.Overall objectives of the Directive 3.2.The determination of GES is central to MSFD implementation 3.3.Provisions of the Directive in relation to GES 3.3.1.The definitions of environmental status and good environmental status (Article 3) 3.3.2.GES Descriptors (MSFD Annex I) 3.3.3.GES elements (ecosystem elements and pressures of MSFD Annex III) 3.3.4.GES criteria and methodological standards (Article 9(3); GES Decision) 3.4.Relationship between the Directive and the GES Decision 3.5.Relationship between GES (Article 9) and assessments (Article 8)

3.6.Relationship between GES (Article 9) and environmental targets (Article 10) 3.7.Consistency between Member States in the determination of GES (Article 3(5) and 5(2)) 3.8.Updating the determination of GES (Article 17(2)) 4.An integrated framework for MSFD implementation 4.1.An ecosystem-based approach and use of the DPSIR framework 4.2.General principles - activities, pressures, impacts and state 4.3.The nature of a GES determination – state, impact and pressure 4.4.Priorities for MSFD implementation and use of risk-based approaches 4.5.Steps in a prioritised implementation process 5.An integrated process to determination of GES and its assessment 5.1.GES Decision supports an integrated process 5.2.Main steps in the assessment and determination process 5.3.Elements for assessment of progress towards GES 5.3.1.Elements for Article 8(1)(b) assessments: pressures and impacts 5.3.2.Elements for Article 8(1)(a) assessments: ecosystem structure, functions and processes 5.4.Scales of assessment and assessment/reporting areas 5.5.Identifying the GES criteria to be used and how they are assessed 5.6.Determining GES: criteria on quality, proportion, distribution and duration 5.7.Setting of threshold values 5.7.1.Use of reference condition in setting threshold values

5.7.2.On setting threshold values at an appropriate scale 5.8.GES in relation to ecosystem characteristics, dynamics and climate change 5.9.Links to quality standards of other policies 5.10.Expressing the extent to which GES is being achieved 5.11.Reporting on the determination of GES and the extent to which it has been achieved 5.12.Time period for assessments 6.Environmental targets (Article 10) 6.1.Follow-up actions to Article 8 assessments depend on the environmental status 6.2.The nature of environmental targets 6.3.Indicators 6.4.Reference points 6.5.Links to monitoring (Article 11) 6.6.Links to measures (Article 13) 7.Use of risk-based approaches in MSFD implementation 8.Research needs Annex 1.Glossary of terms Annex 2: Quality and proportion aspects of GES – worked examples Annex 3: Criteria for biodiversity and links to other policies



1.Introduction

In 2012 Member States prepared the first elements of their marine strategies for the Marine Strategy Framework Directive (MSFD, Directive 2008/56/EC ). This comprised an initial assessment (Article 8), the determination of good environmental status (GES) (Article 9) and the establishment of a set of environmental targets (Article 10). This first stage in MSFD implementation was supported by the Commission Decision 2010/477/EU on criteria and methodological standards on good environmental status of marine waters, which provided a framework for Member States to determine their GES and to assess the current environmental status of their marine waters. To aid the preparation of the 2012 reports, the Commission released a Staff Working Document which aimed to clarify the relationship between the initial assessment and the criteria for good environmental status ( SEC(2011) 1255 ). In addition, the Common understanding of Articles 8, 9 and 10 (2011) , prepared within the MSFD Common Implementation Strategy (CIS), provided support to the first implementation of these articles in 2012. The Commission’s assessment of this first implementation stage (Article 12 report, COM(2014)97 ) found a considerable divergence in approaches amongst Member States, particularly regarding the determination of GES, the use of Decision 2010/477/EU and the relationship between the determination of GES under Article 9 and the setting of environmental targets under Article 10. The Commission's assessment recommended that Decision 2010/477/EU, together with MSFD Annex III which provided indicative lists of ecosystem characteristics, pressures and impacts, be reviewed and if necessary revised as one key mechanism to help overcome this lack of coherence. This review led to both the 2010 Decision and MSFD Annex III being revised in 2017 as Commission Decision (EU) 2017/848 and Commission Directive (EU) 2017/845 , respectively. The technical work of the review raised various generic or cross-cutting issues, particularly concerning the use of the GES Decision in Member State's determinations of GES under Article 9 and for assessments under Article 8. Further, Annex IV of Staff Working Document SWD/2014/049 , which accompanied the Commission's 2014 Article 12 report, set out some principles which are considered essential in the further implementation of the Directive. The present document aims to further develop and substantiate these principles, taking into account expert discussions within the CIS since SWD/2014/049 was published, to provide guidance on the future updates of Articles 8, 9 and 10 and implementation of the MSFD more generally. The concepts and approaches described here are intended to be generally applicable across all Member States. However, as Member States implement the Directive in the context of differing characteristics of each marine region and subregion and practical challenges which may vary between Member States, they may seek solutions that are adapted from these general approaches. Furthermore, this document presents the state-of-the-art in approaches to implementation of the Directive and the GES Decision. Further experiences in practical implementation, together with improvements in knowledge and understanding, may lead to a need to update some aspects. Section 8 highlights certain knowledge gaps where such improvements in understanding are known to be needed. To assist in understanding the present document, key messages have been highlighted as boxed text. Definitions of terms are provided in Annex 1 and shown in italic bold red text at their first mention. 2.General requirements of the MSFD 2.1.Main implementation stages in a six-year cycle Member States implement the MSFD via the development of a 'marine strategy' for each of their marine regions and subregions (section 2.2.2). These strategies are prepared in stages and reported at specified times, starting in 2012 (Article 5(2)). Updates of these individual stages are undertaken on a six-year cycle, enabling adaptive management and new understanding to be accommodated into the MSFD implementation process. The linkages between the main elements of the strategies and the overall cyclical process of the MSFD are illustrated in Figure 1. This document focuses on the determination of GES and associated assessments of (current) environmental status, but also addresses relationships to the setting of environmental targets and to the monitoring programmes which collect the data needed to monitor progress towards achieving GES and the environmental targets as well as the effectiveness of measures. The outcomes of the assessments inform whether there is need for environmental targets and consequently lead to the measures which are established to achieve (or maintain) GES. 2.2.Geographic scope 2.2.1.Member State marine waters (Article 3(1)) The Directive applies to the ‘marine waters’ of Member States, which are defined in Article 3(1) as: (a)‘waters, the seabed and subsoil on the seaward side of the baseline from which the extent of territorial waters is measured extending to the outmost reach of the area where a Member State has and/or exercises jurisdictional rights, in accordance with the Unclos’. This is understood to include territorial waters (0-12nm), contiguous zones (12-24nm), exclusive economic zones (out to 200nm or median lines with neighbouring states) and other types of jurisdictional designation; additionally where a Member State has informed the Commission that it possesses and/or exercises jurisdictional rights on a Continental Shelf area which extends beyond these zones, the Directive applies also to the seabed and subsoil of these areas. (b)‘coastal waters as defined by Directive 2000/60/EC, their seabed and their subsoil in so far as particular aspects of the environmental status of the marine environment are not already addressed through that Directive or other Community legislation’. This indicates that waters inside the baseline and extending up to the landward boundary of coastal waters are within the scope of the MSFD as far as MSFD-relevant aspects are concerned which are not already covered by the Water Framework Directive (WFD) or other Union legislation. Waters designated as Transitional Waters under the WFD are excluded from the geographic scope of the MSFD. Beyond these areas of national jurisdiction there is a need to cooperate with neighbouring states in the same marine region or subregion (sections 2.2.2 and 2.3). 2.2.2.MSFD marine regions and subregions (Article 4) In support of an ecosystem-based approach to delivery of the Directive, Article 4 indicates that Member State waters form an integral part of four marine regions of Europe, two of which (North-East Atlantic Ocean, Mediterranean Sea) are each divided into four subregions. These MSFD regions and subregions are illustrated in Figure 2.

The regions and subregions provide the basis for implementation of the marine strategies following an ecosystem-based approach and for defining scales and areas for reporting. Article 4 further provides for subdivision of each region or subregion, thus providing an important tool for delivery of an ecosystem-based approach below the scale of region and subregion. The scales used may differ between the GES determination (Article 9) and assessments of the extent to which GES has been achieved (Article 8). The scales used may differ between the GES Descriptors (section 3.3.2) and in relation to environmental targets (Article 10). See section 5.4 for further details. Note 1: The area shaded in purple and white indicates an area to which both the United Kingdom and the Government of the Kingdom of Denmark together with the Government of the Faroes have transmitted overlapping submissions to the Commission on the Limits of the Continental Shelf (CLCS) in fulfilment of their respective rights and obligations under Article 76 and Annex II to the United Nations Convention on the Law of the Sea in order to determine entitlement of outer continental shelf areas. This map should not be used in any way to prejudice the determination of that question by the CLCS in due course. Note 2: The area shaded in black and white shows the delineation of the outer limits of the continental shelf beyond 200 M from the territorial sea baselines of France, Ireland, Spain and the United Kingdom in respect of the area of the Celtic Sea and the Bay of Biscay, as provided by the four countries to the Commission on the Limits of the Continental Shelf (CLCS) and included in its recommendations issued on 24 March 2009. The map of the continental shelf’s extent shall be used without prejudice to the agreements that will be concluded in due course between these Member States on their marine borders in this area. Note 3: The seas of Azov and Marmara are shown as shaded as they do not fall within the geographic scope of application of the Bucharest Convention. 2.3.Regional and subregional implementation (Article 5 and 6) Article 5(1) sets out the need for Member States to implement the Directive in respect of each region or subregion in which it has marine waters. This regional or subregional approach can be considered to have two aspects: a) those related to cooperation between Member States and b) those related to cooperation with non-EU states in the region or subregion. This regional or subregional approach of the Directive provides an essential framework for the successful implementation of the Directive. It is particularly important because the characteristics of marine waters and their biodiversity are shared across each region or subregion and because many of the issues (pressures) which need to be addressed to achieve GES can only be effectively addressed through joint or common actions within the region or subregion. In addition, the implementation could differ in each region or subregion, for example, to reflect the differing characteristics of each region or subregion and the differing (degrees of) anthropogenic pressure it faces. Within each region or subregion, Member States are required to cooperate amongst themselves to ensure their marine strategies are coherent and coordinated, and to endeavour to follow a common approach to their implementation (Article 5(2)). This applies to each element of Member States' marine strategies (also referred to as 'plan of action' in Article 5(2)): assessment, determination of GES, establishment of environmental targets, establishment and implementation of monitoring programmes, development and entry into operation of programmes of measures. The practical delivery of Article 5(2) requirements can be at regional or subregional level, or a mixture of the two. Because Member States are obliged to implement the Directive in their marine waters and these may form only part of the whole region or subregion, some aspects can be achieved through direct cooperation between several Member States in the region or subregion, rather than always involving all states in the region or subregion. The link to non-EU states within a region or subregion is important because achieving GES may be dependent upon actions by other states within the region or subregion, due to the inter-connectedness of their waters. This is particularly relevant where anthropogenic pressures arise outside Member States’ waters but have transboundary effects which prevent the achievement of GES within their waters. In such situations, cooperation with non-EU states is necessary to address the issues. There may, however, also be situations where it is appropriate to collect data and undertake assessments, for example for commercial fish and other species whose ranges extend beyond Member States’ national borders, and for which joint management of them is important to secure their good status. Article 6 indicates that ‘Member States shall, wherever practical and appropriate, use existing regional institutional structures, including those under Regional Sea Conventions’ (RSC). The four RSCs dealing with seas around Europe (Helsinki Convention, OSPAR Convention, Barcelona Convention and Bucharest Convention) correspond to the four MSFD marine regions. They provide a key mechanism for such cooperation, bringing together the States which share the region and having broadly similar objectives to protect the marine environment as the MSFD. For regional cooperation issues related to commercial fishing, the Regional Fisheries Management Organisations (RFMOs), including the General Fisheries Commission for the Mediterranean (GFCM), the North East Atlantic Fisheries Commission (NEAFC) and the International Commission for the Conservation of Atlantic Tunas (ICCAT), have an important role. Because the need for cooperation does not just extend across the marine waters of a region or subregion, but also to the freshwater catchment areas, particularly for land-based sources of pollution, the Directive also indicates a need for coordination and cooperation with land-locked Member States. Here it makes the links with the WFD, where the River Basin Management Plans provide an important mechanism for addressing land-based sources of pollution. Exchange of information and cooperation between the River Basin District Authorities and International River Commissions on the one side and the Regional Sea Conventions on the other side is needed. Overall, these cooperation processes indicate that there is not a single way in which regional and subregional aspects of the Directive can be implemented, but a variety of approaches depending on the particular needs. Hereafter the term (sub)regional is used to reflect the multiple approaches that may be appropriate. 2.4.Integration with other EU legislation Article 1(4) states ‘This Directive shall contribute to coherence between, and aim to ensure the integration of environmental concerns into, the different policies, agreements and legislative measures which have an impact on the marine environment.’ The Directive explicitly mentions the following Union legislation: a.Urban Waste Water Treatment Directive 91/271/EEC b.Habitats Directive 92/43/EEC c.Water Framework Directive 2000/60/EC

d.Environmental Information Directive 2003/4/EC e.Bathing Water Directive 2006/7/EC f.INSPIRE Directive 2007/2/EC g.Birds Directive 2009/147/EC The Directive refers also to the need to encompass international and regional agreements (e.g. regarding protected species and habitats, and marine protected areas) and, due to the topics addressed by the Directive, needs to engage in further policies, such as the Common Fisheries Policy (CFP), the Common Agriculture Policy and the Maritime Spatial Planning Directive (MSPD, 2014/89/EU), in order to achieve its goals effectively. This linkage with other policies is illustrated in Figure 3. Integration of the MSFD with these other policies can be considered in relation to the environmental objectives to be achieved, assessments against these objectives, spatial overlaps, monitoring requirements and the measures implemented to achieve the objectives. This document focuses on the first three of these issues (in relation to Articles 9 and 8). In accordance with Article 1(4) of the Directive, the GES Decision has set out specifically how the determination and assessment of GES is linked with the standards and assessments under other Union policies (such as WFD, Habitats Directive and Birds Directive). Legislation adopted after the MSFD, such as CFP and MSPD, refer to the MSFD itself, thereby indirectly adding to the list in Article 1(4). This helps achieve both coherence between policies (through not having different assessment outcomes for the same topic) and reduce administrative burden (by assessing once, using for several policy needs). The differing requirements of the policies, and the processes in place to establish methods and standards to be used, can mean that harmonisation across policies is a complex task that may only be partially achievable. Further details are given in section 5.9. 3.Determination of good environmental status (Articles 3(5) and 9, Annexes I and III) This section focuses on the provisions of the Directive that relate to the determination of GES. The assessments of environmental status (Article 8) in relation to this determination are considered in section 5. Section 6 addresses the establishment of environmental targets (Article 10) which are needed when GES has not yet been achieved. 3.1.Overall objectives of the Directive Article 1 sets the wider context within which GES is to be determined. This includes that: ‘1. Member States shall take the necessary measures to achieve or maintain good environmental status in the marine environment by the year 2020 at the latest.’ (Article 1(1)); ‘2. […] marine strategies shall be developed and implemented in order to: (a) protect and preserve the marine environment, prevent its deterioration or, where practicable, restore marine ecosystems in areas where they have been adversely affected; (b) prevent and reduce inputs in the marine environment, with a view to phasing out pollution […], so as to ensure there are no significant impacts on or risks to marine biodiversity, marine ecosystems, human health or legitimate uses of the sea.’ (Article 1(2)); ‘3. Marine strategies shall apply an ecosystem-based approach to the management of human activities, ensuring that the collective pressure of such activities is kept within levels compatible with the achievement of good environmental status and that the capacity of marine ecosystems to respond to human-induced changes is not compromised, while enabling the sustainable use of marine goods and services by present and future generations.’ (Article 1(3)).

3.2.The determination of GES is central to MSFD implementation Good environmental status (GES) is the core concept that has to be achieved by Member States in implementing the MSFD. All operational provisions of the Directive are in one way or another linked to GES, which is the central objective allowing the measurement of progress and success in its implementation: a.It is needed as the benchmark against which to assess current environmental status (Article 8, particularly Article 8(1)(a) and 8(1)(b)); b.The assessment under Article 8 determines whether and what environmental targets are needed under Article 10 in order to achieve GES; c.These targets, in turn, determine what measures are needed under Article 13 to achieve and/or maintain GES; d.It guides the monitoring needed under Article 11, which provides the data and information needed to assess whether GES has been achieved or is being maintained, and to assess progress in delivery of the environmental targets and for assessing the effectiveness of measures; e.It provides the benchmark for assessing if an exception is warranted under Article 14(1) and, read in conjunction with the precautionary principle, for assessing if there is significant risk to the marine environment which could warrant the application of Article 14(4). It is therefore paramount that Member States determine GES, and monitor and assess whether it has been achieved. The associated implementation of related articles depends on having sufficient clarity in this determination (ideally in a quantitative way) to enable adequate decision-making in implementation of the Directive. Further details are given in section 5. 3.3.Provisions of the Directive in relation to GES GES is defined in Article 3(5) and further elaborated by the descriptors in MSFD Annex I. GES is further determined through the provisions of Article 9. This is based firstly on EU-level criteria and methodological standards which are set out in the GES Decision, adopted under Article 9(3), and secondly by Member States when determining the characteristics of GES in accordance with Article 9(1). The determination of GES under Article 9 is additionally guided by the indicative list of elements provided in MSFD Annex III. GES is thus progressively refined from its high-level definition in Article 3(5) via the Descriptors of MSFD Annex I, the elements of MSFD Annex III and the criteria and methodological standards of Article 9(3) through to the more specific determinations of Article 9(1). This is illustrated, with a worked example, in Figure 4. In this context, the term 'determination' is taken to mean a more precise definition of GES than is provided in the Directive or the GES Decision, that allows for an assessment of whether GES has been achieved or not. Figure 4 presents an architecture for how the GES Decision under Article 9(3) relates to determination of GES. This architecture has been developed to ensure the role and contents of each provision are fully compatible and avoid overlap. This overall structure has arisen from the ongoing experiences in implementation of the Directive at Union, regional and national levels and is aimed at promoting greater coherence and consistency in the determination and assessment of GES in the next implementation cycles, including through the common use of particular terminology. 3.3.1.The definitions of environmental status and good environmental status (Article 3) The definition of environmental status in Article 3(4) provides a high-level perspective on what needs to be taken into account when assessing the ‘state’ of the environment: ‘the structure, function and processes of the constituent marine ecosystems together with natural physiographic, geographic, biological, geological and climatic factors, as well as physical, acoustic and chemical conditions, including those resulting from human activities inside or outside the area concerned’. The definition of good environmental status (GES) in Article 3(5) further elaborates on this by defining the high-level goal of the Directive: ‘good environmental status' means the environmental status of marine waters where these provide ecologically diverse and dynamic oceans and seas which are clean, healthy and productive within their intrinsic conditions, and the use of the marine environment is at a level that is sustainable, thus safeguarding the potential uses and activities by current and future generations, i.e.: a.the structure, functions and processes of the constituent marine ecosystems, together with the associated physiographic, geographic, geological and climatic factors, allow those ecosystems to function fully and to maintain their resilience to human-induced environmental change. Marine species and habitats are protected, human-induced decline in biodiversity is prevented and diverse biological components function in balance; b.hydro-morphological, physical and chemical properties of the ecosystems, including those properties which result from human activities in the area concerned, support the ecosystems as described above. Anthropogenic inputs of substances and energy, including noise, into the marine environment do not cause pollution effects.’

Good environmental status is further referenced in Articles 5(2), 5(3), 9(1), 9(3), 10(1), 13(1), 14(1), 14(2), 14(4), 15(1), 17(2), 19(2), MSFD Annex I, MSFD Annex IV.2, IV.3, IV.10, IV.12, MSFD Annex V.1, V.4 and MSFD Annex VI.6. The Directive also indicates the need to prevent deterioration (Articles 1(2)(a) and 14(4)). Article 1(2)(a) also refers to restoration of marine ecosystems, where practicable, in areas where they have been adversely affected. 3.3.2.GES Descriptors (MSFD Annex I) MSFD Annex I provides a set of eleven qualitative Descriptors for use in the determination of GES under Article 9 (Table 1). These provide more specific objectives for GES than is provided in the Article 3(5) definition. No. Short name MSFD Annex I text D1 Biodiversity Biological diversity is maintained. The quality and occurrence of habitats and the distribution and abundance of species are in line with prevailing physiographic, geographic and climatic conditions. D2 Non-indigenous species (NIS) Non-indigenous species introduced by human activities are at levels that do not adversely alter the ecosystems. D3 Commercial fish and shellfish Populations of all commercially exploited fish and shellfish are within safe biological limits, exhibiting a population age and size distribution that is indicative of a healthy stock. D4 Food webs All elements of the marine food webs, to the extent that they are known, occur at normal abundance and diversity and levels capable of ensuring the long-term abundance of the species and the retention of their full reproductive capacity. D5 Eutrophication Human-induced eutrophication is minimised, especially adverse effects thereof, such as losses in biodiversity, ecosystem degradation, harmful algae blooms and oxygen deficiency in bottom waters. D6 Sea-floor integrity Sea-floor integrity is at a level that ensures that the structure and functions of the ecosystems are safeguarded and benthic ecosystems, in particular, are not adversely affected. D7 Hydrographical conditions Permanent alteration of hydrographical conditions does not adversely affect marine ecosystems. D8 Contaminants Concentrations of contaminants are at levels not giving rise to pollution effects. D9 Contaminants in seafood Contaminants in fish and other seafood for human consumption do not exceed levels established by Community legislation or other relevant standards. D10 Litter Properties and quantities of marine litter do not cause harm to the coastal and marine environment. D11 Energy, including underwater noise Introduction of energy, including underwater noise, is at levels that do not adversely affect the marine environment. The qualitative descriptors can be broadly characterised as relating to: a.Particular aspects of marine ecosystem state (which are potentially subject to any or multiple pressures): D1 (biodiversity), D3 (commercial fish and shellfish), D4 (food webs) and D6 (sea-floor integrity); b.Particular anthropogenic pressures (which can potentially affect any aspect of marine ecosystem state): D2 (non-indigenous species), D5 (eutrophication); D7 (hydrographical conditions); D8 (contaminants), D9 (contaminants in seafood), D10 (litter) and D11 (energy, including underwater noise). It should be noted that this state and pressure categorisation at Descriptor level is not maintained at the criteria level in the GES Decision, where a more mixed pressure/impact/state approach per descriptor is followed, and where impact is, in effect, a particular reflection of state (see section 4.3). 3.3.3.GES elements (ecosystem elements and pressures of MSFD Annex III) Whilst the descriptors of MSFD Annex I provide the basis for determining the environmental quality (GES) which is to be achieved, MSFD Annex III can be considered as providing the elements to be used when determining that quality (GES) under Article 9(1) and consequently for assessments of whether GES has been achieved under Article 8. These lists comprise: a.Species groups (of marine birds, mammals, reptiles, fish and cephalopods); broad habitat types of the water column (pelagic) and seabed (benthic) and other habitat types; ecosystem structure, functions and processes (physical and hydrological, chemical and biological characteristics, functions and processes) (MSFD Annex III Table 1), and b.Anthropogenic pressures (biological, physical, substances, litter and energy) which can adversely affect the state of the marine ecosystems and their elements (MSFD Annex III Table 2a). The elements given in MSFD Annex III are indicative (i.e. should only be used where relevant to a particular (sub)region) and are broadly-defined. They are further specified at Union level in the GES Decision and at (sub)region level by Member States under Article 9(1) in order to provide clarity and consistency in how GES is determined and assessed (Figure 4). The relationship between MSFD Annex I and the original (2008) MSFD Annex III was not explicit. The review of the Decision 2010/477/EU was therefore accompanied by a review of the original MSFD Annex III, leading to both being updated in 2017. These revisions provide clarity on the relationships between MSFD Annex I, MSFD Annex III and the GES Decision, following the approach outlined in Figure 4. The role of MSFD Annex III is as follows: a.To provide an indicative list of elements and parameters for monitoring and assessment of state, pressure and impacts under Article 8(1)(a) and (1)(b) and Article 11, linked explicitly to the descriptors of MSFD Annex I. Each of the eleven descriptors has been specifically linked to particular elements in MSFD Annex III. However MSFD Annex III includes additional pressures, which are not explicitly referred to in a descriptor but which should be considered where relevant under Article 8(1) assessments; b.To provide an additional indicative list of elements and parameters for monitoring which may be needed to support environmental assessments (e.g. physical and hydrological parameters useful for indicating wider climatic variation); c.To provide a new indicative list of uses and activities to be considered under MSFD Article 8(1)(b) and (1)(c). The list distinguishes those uses and activities which are ‘sea-based’, and thus relevant for Article 8(1)(b) and (c), from those which are ‘land-based’ and thus relevant only for Article 8(1)(b) in the context of the pressures they may generate on the marine environment. In updating the lists for the revised MSFD Annex III, a review was made of other key policies and those used by the RSCs to ensure the lists were comprehensive.

GES elements are further specified in the GES Decision (section 5.3). 3.3.4.GES criteria and methodological standards (Article 9(3); GES Decision) Key message The criteria and methodological standards under Article 9(3) and specifications and standardised methods under Article 11(4) provide EU-wide minimum requirements for the determination and assessment of GES. The Commission has delegated powers under Article 9(3), and in accordance with the provisions of Article 25, to lay down criteria and methodological standards to be used by Member States ‘to ensure consistency and to allow for comparison between marine regions or subregions of the extent to which GES is being achieved’. Article 3(6) defines ‘criteria’ as ‘distinctive technical features that are closely linked to qualitative descriptors’. To fulfil their role these criteria need to include quality elements (e.g. species, habitats, pressure types), parameters (e.g. concentration of a substance, extent of a pressure or habitat) and quality standards (criteria threshold values). The criteria enable assessment of the status of the elements in MSFD Annex III. Monitoring and assessment in relation to these criteria should follow the specifications and standardized methods set in accordance with Article 11(4). The first use of Article 9(3) led to Decision 2010/477/EU which guided, in particular, the 2012 stage of implementation and the 2014 monitoring programmes. The application of Decision 2010/477/EU revealed that it provided insufficient detail and clarity to support the determination of GES, leading to its revision in 2017. The following specifications are included in the revised GES Decision: a.Elements for assessment (of whether GES has been achieved) (section 5.3); b.Criteria for assessment of the elements, including parameters to be used (section 5.5); c.Threshold values for assessing quality and trends (including distinguishing 'In GES' from 'Not in GES') (sections 5.6-5.7); d.Assessment scales (section 5.4); e.Use of the criteria (e.g. to express the extent to which GES is achieved, or for other descriptor assessments) (section 5.10); f.Approaches to and methods for monitoring to collect the data needed for assessment; g.Aggregation methods for the data (spatial, temporal); h.Units of measurement for the criteria. Where available, the elements, threshold values and methods for use of criteria are drawn from existing EU policies (section 2.4 and section 5.9) and where not the GES Decision makes provision for these to be set at EU, regional or subregional level. The information provided for points (f) and (g) is not complete. The criteria and methodological standards under Article 9(3) and specifications and standardised methods under Article 11(4) provide EU-wide minimum requirements for the determination and assessment of GES. To avoid confusion between the use of the term ‘criteria’ in this specific context and its use in other respects (such as criteria used to guide indicator selection or selection of species for assessments), it is recommended that the criteria of the GES Decision be referred to as ‘GES criteria’ in situations where there could be confusion. 3.4.Relationship between the Directive and the GES Decision The interrelationships between Articles 8 and 9, MSFD Annexes I and III and the GES Decision are illustrated in Figure 5. The integrated implementation of these provisions is described in section 5. Article 9(3) provides for criteria and methodological standards to be laid down ‘in such a way as to ensure consistency and to allow for comparison between marine regions or subregions of the extent to which good environmental status (GES) is being achieved’, whilst Article 9(1) provides for Member States to determine a set of characteristics of GES, but without specific reference to the criteria set under Article 9(3).

The inter-relationship between these two provisions can be considered as follows: a.The GES Decision provides a common Union-level framework for determining GES, thereby helping to ensure consistency across the marine regions in the determinations of GES; it does this through specifying (in generic terms or providing for these to be specified at Union or (sub)regional level) the elements, parameters and geographic scales of assessment, the threshold values for each criterion and methods for use of the criteria; b.The determination of a set of characteristics of GES under Article 9(1) by Member States provides specificity to these criteria and methodological standards for each region or subregion, thereby reflecting the particular ecological characteristics and differing nature of pressures in each region or subregion. Additional characteristics, not included in the GES Decision, can be included in this determination. The GES Decision therefore provides a basis and structure for determining GES, providing a further level of detail to that of MSFD Annexes I and III. However, it does not in itself provide a determination of GES, as this requires the additional specificity to be set by Member States for each region or subregion. The GES Decision has been structured to make explicit its relationship to MSFD Annexes I and III, and to the assessments required under Article 8(1)(a) and (1)(b), which relate to the assessment of current environmental status and of predominant pressures and impacts respectively. It also supports a more integrated approach to the determination and assessment of GES (section 5.1, Figure 8), as does the structure and content of MSFD Annex III. This has been achieved by: a.Structuring the GES Decision in two parts, each referring explicitly to the relevant Descriptors of MSFD Annex I, to the indicative elements of MSFD Annex III and to the relevant paragraphs of Article 8(1); b.The pressure-related descriptors are presented first (Part I), as logically these should be considered first under the Article 8 assessments in order to provide information on the level of impacts from each of the pressures assessed. These assessments of impacts should then inform the assessments of the different ecosystem elements (Part II), whose overall status effectively reflects the cumulative effects of the impacts from all the pressures to which they are subject. c.Part I of the GES Decision supports the assessments required under Article 8(1)(b) concerning an analysis of the predominant pressures on the marine environment and their impacts; it includes the criteria and methodological standards for the pressure-related descriptors which are directly linked to the indicative list of pressures in MSFD Annex III Table 2a; there are additional pressures in this table which are not linked to a pressure-based descriptor and thus have no GES criteria defined. They, nevertheless, may be of importance in some areas and for some ecosystem elements and therefore warrant assessment; d.Part II of the GES Decision supports the assessments required under Article 8(1)(a) concerning an analysis of the essential features and characteristics and current environmental status; it includes the criteria and methodological standards for the state-related descriptors which are directly linked to the indicative list of ecosystem elements in MSFD Annex III Table 1; e.To ensure the predominant pressures of MSFD Annex III Table 2a are adequately addressed under Part I, the criteria relating to fishing pressure (extraction of species) and to physical loss and disturbance have been placed in this part, even though labelled in relation to the state-based Descriptors D3 and D6. Criterion D3C1 addresses the impacts of fishing on commercial species (the level of mortality), whilst criteria D3C2 and D3C3 address the state of commercial fish and shellfish to be considered also under Part II. Criteria D6C1, D6C2 and D6C3 have their origins in the D6 criteria of Decision 2010/477/EU, and are focused only on the assessment of the pressures ‘physical loss’ and ‘physical disturbance’; they provide an important contribution to the broader assessment needed for Descriptor 6, which is addressed fully in Part II (in combination with assessments of seabed habitats of Descriptor 1). 3.5.Relationship between GES (Article 9) and assessments (Article 8) The Directive does not make clear the relationship between the determination of GES under Article 9 and the assessments (of current environmental status and of the pressures and their impacts) under Article 8. However, from the overall purpose of the Directive, it is logical that the determination of GES should form the benchmark against which to assess current status and hence progress towards GES. In the 2012 stage of the first MSFD implementation cycle, the determination of GES needed to take account of the initial assessment, as well as the criteria in Decision 2010/477/EU. The initial assessment was particularly relevant for identifying the specific ecological characteristics and pressures and impacts for each region or subregion, thus providing a basis upon which to determine GES. In this sense the determination of GES in 2012 could be considered as dependent upon firstly undertaking the initial assessment and therefore considered as a subsequent step in the implementation process. In practice, most Member States followed this approach and thus did not specifically use their 2012 determination of GES as the benchmark against which current environmental status in 2012 was assessed. In the second and subsequent implementation cycles, the updating of the GES determination should be done in close association with updating of the initial assessment, as the two elements are intricately linked, such that at each reporting cycle the updated assessment of current environmental status is based upon the updated determination of GES reported at the same time. See Section 5.11 regarding the reasons for updating the determination of GES. 3.6.Relationship between GES (Article 9) and environmental targets (Article 10) Articles 9 and 10 have distinct roles in the MSFD implementation process, each with different legal obligations which are not interchangeable. The main purpose of Article 9 is to determine the specific environmental objectives of the Directive (i.e. what is GES) in sufficient (and where possible quantifiable) detail to be able to know whether they have been achieved or not for the different descriptors and in accordance with the overall definition in Article 3(5). The main purpose of Article 10 is to establish a set of environmental targets to guide progress towards achieving these objectives (GES). This indicates that Article 10 provides a declaration of intent to take action, compared with the objective-led role of Article 9. For example, setting an environmental target for the maximum allowable input of nutrients to the sea in order to lead to nutrient levels in the sea which do not give eutrophication effects (Descriptor 5). This 'declaration' is then delivered through the Programmes of Measures (Article 13) as the ‘measures shall be devised on the basis of the initial assessment … and by reference to the environmental targets’ (Article 13(1)). To continue the example above, nutrient input reduction targets could be achieved through various possible measures, such as controls on the use of fertilisers in agriculture or the use of phosphates in detergents, and by improving urban waste water treatment. Targets thus provide an operational tool, used in conjunction with the programme of measures, for the management of human activities and their pressures and for actions which should lead to improvements in the environmental status of marine waters and ultimately to GES. Targets are not meant to be used to provide a more refined determination of GES, as was often the case in the first reporting of environmental targets in 2012. 3.7.Consistency between Member States in the determination of GES (Article 3(5) and 5(2))

From the overview given in Figure 4 it can be seen that some aspects of GES determinations are laid down in the Directive and in the GES Decision, whereas further specifications are determined, where needed, at regional and subregional level via Article 9(1). This task under Article 9(1) is the responsibility of Member States, undertaken in collaboration with other Member States, as required under Article 5(2), in order to ensure GES is determined at the level of the marine region or subregion in accordance with Article 3(5), using, ‘where practical and appropriate, existing regional institutional cooperation structures, including those under the RSCs’ (Article 6). The provisions of the Directive thus provide for levels of consistency in the determination of GES, partly at Union level and partly at (sub)regional level. This Union and (sub)regional consistency is important to ensure a ‘level playing field’ across Member States in the different stages of the MSFD implementation process. 3.8.Updating the determination of GES (Article 17(2)) The Directive provides in Article 17 for a six-year review and updating of each element of the marine strategies. For GES, this is a key mechanism to refine the determinations to take account of developments since the previous determination. See section 5.11 for further details. 4.An integrated framework for MSFD implementation 4.1.An ecosystem-based approach and use of the DPSIR framework The Directive calls for ‘an ecosystem-based approach to the management of human activities, which should ensure that the collective pressure of such activities is kept within levels compatible with the achievement of GES and that the capacity of marine ecosystems to respond to human-induced changes is not compromised, whilst enabling the sustainable use of marine goods and services by present and future generations’ (Article 1(3)). Whilst the ecosystem-based approach has a number of facets, its relevance in relation to the determination, assessment and achievement of GES is focused upon here. The relationship between human activities, their pressures and the consequent state of the environment is encompassed within the well-established DPSIR (Drivers-Pressure-State-Impact-Response) framework for environmental management. For MSFD purposes, the framework has been modified to address ambiguities in use of the terms ‘driver’ and ‘impact’ and to accommodate the concept of ecosystem services more explicitly. Human activities are distinguished from drivers, as these are the consequence of drivers and are a specific focus of the Directive (e.g. under Article 8(1)(c)); impacts are distinguished into those on the environment (resulting from pressures and affecting state) and those affecting ecosystem services (e.g. as 'costs of degradation' under Article 8(1)(c)). This modified framework is referred to here as the DAPSES-MMM framework (Drivers-Activities-Pressures-State-Ecosystem Services: Management, Measures and Monitoring); it is illustrated in Figure 6 which shows its links to relevant MSFD articles. This model can be closely associated with the different main stages of MSFD implementation and thus follow much of the established understanding of how to improve environmental quality. The Directive requires an economic and social analysis of uses of the marine waters and of the cost of degradation (Article 8(1)(c), ~Drivers, Impacts on ecosystem services), pressures and impacts (Article 8(1)(b), ~Pressures, Impacts on environmental state), and current environmental status (Article 8(1)(a), ~State). In Article 10 a set of environmental targets are to be established and in Article 13 the Directive calls for a programme of measures to achieve these targets and consequently achieve or maintain GES (~Response). 4.2.General principles - activities, pressures, impacts and state Section 4.1 introduced the DAPSES-MMM (DPSIR) framework as an underlying basis for implementation of the Directive. In section 3.5, the inter-relationships between the determination of GES and its assessment were outlined. In this section, these two aspects are further elaborated. The activity-pressure-(impact)-state part of the DAPSES framework can be directly related to the needs of the Article 8 assessments, where an integrated approach to the assessments, across all GES descriptors and between pressures and state, is needed. This is because an assessment of current environmental status (Article 8(1)(a)) is, in effect, an assessment of the state of the environment that reflects the range of environmental impacts (adverse effects), including cumulative impacts/effects, acting upon it. As these impacts are in turn caused by the pressures exerted on the environment by human activities (Article 8(1)(b)), these elements of the initial assessment are intricately linked. Pressures can be considered in two ways: a.At source – i.e. close to the activity generating the pressure. This aspect is particularly relevant for setting environmental targets and for measures as these need to focus on reducing the pressures, when needed to achieve or maintain GES. Some pressures, such as nutrients, contaminants and litter, originate on land and enter the marine environment as diffuse sources (including via the atmosphere) or from point sources. Pressures generated by sea-based activities may remain closely associated to those activities (e.g. extraction of species by fishing and physical disturbance by dredging or bottom trawling), while others may dissipate away from the activity (e.g. contamination from oil extraction activities, noise from shipping); b.At sea – i.e. the level of the pressure in the marine environment (to which the different elements of the ecosystem are subjected). This aspect is particularly relevant for determining GES (for the pressure-based descriptors) and for assessment of environmental status in relation to GES.

These relationships, for multiple activities, pressures and state elements, are illustrated in Figure 7, which additionally shows the main scope of Articles 9, 10 and 13 in relation to activities, pressures, impacts and state: a.Article 9 GES should be determined by reference to both state elements covered by Article 8(1)(a) and pressure and impact elements covered by Article 8(1)(b), noting that this refers to the levels of pressure in the marine environment (at sea); b.Article 10 environmental targets should focus on addressing the pressures which are preventing GES from being achieved, or which put at risk the maintenance of GES. In this case, the targets should focus on the pressures at source, although pressure reduction at sea may also be desirable (e.g. for litter); c.Article 13 programmes of measures are likely to be most effective when directly addressing those activities contributing to the generation of the pressures (which are preventing GES from being achieved). These links to the DAPSES (DPSIR) model are important regarding the application of the terms pressure, impact and state (status) as used in the Directive. Because the prime focus of the Directive is the achievement of GES, requiring assessments of environmental status and progress towards achievement of GES, these terms need to be used in this context. Table 2 provides illustrated examples of each term to help demonstrate their application, differences and relationships. Descriptor Activity Pressure at source Pressure at sea Environmental impact (adverse effect) State (status) D2 Ship/boat transport Introductions of non-indigenous species via ship hulls and ballast water Populations of NIS established in marine waters Changed composition of native marine communities, displacement of native species Altered condition of pelagic and benthic communities, and bird, mammal and fish communities. D3 Fishing Removal of commercial fish and other (non-commercial) species Mortality of fish and other species Reduced population size, altered age/size structure of population D5 Agriculture Introduction of nutrients through rivers or directly from land Raised nutrient levels (enrichment) in sea Increased algal productivity, oxygen depletion, benthic mortality, fish mortality Altered condition of plankton and benthic communities, hypoxia/anoxia D6 Fishing (demersal/ benthic) Physical disturbance of seabed Changes in sediment structure, injury and mortality of species Altered benthic community and habitat condition D6/D7 Infrastructure developments Change in seabed substrate (e.g. to concrete, metal) Loss of natural habitat, altered hydrological conditions (D7) Habitat loss, altered habitat condition (hydrological conditions and community) D8/D9 Industry (emissions) Contaminants in atmosphere Contaminants in water, sediment and biota Effects of contaminants on life history aspects of species; accumulation of contaminants in seafood and human health effects Altered condition of species (e.g. reproductive ability) D10 Tourism Input of litter – discarded on beach Litter on seabed Smothering of benthic habitats, injury to marine animals Altered habitat condition, affected condition or population size of species D11 Pier-piling for wind farms Noise from piling Noise level in sea Disturbs cetaceans, moving away from noise Altered species distribution Because the use of these terms (pressure, impact and state) across policies and countries is quite variable, it is important for MSFD purposes to apply them in a consistent manner. Based on the application of the term ‘pressure’ in the MSFD context and upon a review of the types of pressures in use under other Directives and by the RSCs, the term pressure in this document is as defined in Annex I to this document. 4.3.The nature of a GES determination – state, impact and pressure The determination of GES concerns the desired state of the marine environment, including the structure, functions and processes of its constituent marine ecosystems. This is reflected in the state-based definition of GES in Article 3(5) and in the general theme of the descriptors in MSFD Annex I, which either express a particular state which is to be achieved or a particular state to be achieved in relation to a specific pressure. Because the environment can be adversely affected (impacted) by pressures from human activities, GES can also be expressed in relation to specific environmental impacts (i.e. a more specific way to express the desired state which relates directly to the particular anthropogenic pressures). For example, nutrient enrichment can lead to changes in plankton biomass (chlorophyll-a concentrations) and to oxygen depletion, and thus provide a focus for how to determine GES for Descriptor 5 on eutrophication. Determining GES also includes defining the acceptable levels of pressures in the marine environment (at sea). This is because: a.the ‘pressures’ may be deviations from natural conditions (e.g. nutrients, certain contaminants, underwater noise) and thus can also be considered state elements; b.there can be a known causal relationship between the level of the pressure and its adverse effects (impacts) on marine ecosystem elements, enabling a level of pressure to be determined, when there is sufficient evidence, which should ensure acceptable levels of impact on ecosystem elements. For example, the levels of nutrient enrichment and hazardous substances in the sea (for Descriptors 5 and 8) which are considered to ‘equate’ to GES, can be determined based on established effects (impacts) on particular ecosystem elements; c.an ‘acceptable pressure level’ in the marine environment is needed for situations where the pressure-impact relationship is not yet fully understood. This should follow the precautionary principle, by using precautionary levels of the pressure until the knowledge gaps for determining the pressure-impact relationship are closed. There can be refinement over time of this ‘acceptable pressure level’, based on improved understanding of this pressure-impact relationship. For litter (D10) and underwater noise (D11), scientific understanding of impacts on the environment is currently more limited and so setting precautionary pressure levels may be the only feasible option at present. This approach is relevant for each of the pressure-based descriptors: the desired levels in the marine environment of non-indigenous species (D2), fishing mortality (D3), enriched nutrients and organic matter (D5), physical disturbance (D6), physical loss and associated alteration of hydrographical conditions (D6, D7), contaminants (D8, D9), litter (D10) and inputs of energy, including underwater noise (D11) are determined under Article 9. Further pressures, such as those listed in MSFD Annex III Table 2a but which are not specified in one of the descriptors, could also be included in a GES determination. This consequently means that levels of non-indigenous species, nutrients, contaminants, litter and noise in the sea are referred to as the level of the pressure in the marine environment and are needed to assess their impacts on state elements (species, habitats, food webs or wider ecosystem) of the marine environment. It is common practice to determine both the acceptable pressure level and the associated state characteristics which are considered to be good status (e.g. for D5 eutrophication, for D3 commercial fish and shellfish). Both aspects are needed in the MSFD implementation process, to enable responses to measures to be assessed (via reductions in the level of pressure at sea) and consequent improvements in environmental status to be seen (via reductions in impacts and recovery of the ecosystem). From the above, and due to the nature of those Annex I Descriptors which focus on pressures and their impacts, assessments of environmental status (in relation to the determination of GES) are not confined to Article 8(1)(a), but should also include those under Article 8(1)(b). 4.4.Priorities for MSFD implementation and use of risk-based approaches

The broad subject matter and wide geographic scope of the Directive present significant challenges to its implementation, to ensure it can deliver satisfactorily according to its objectives in an effective and efficient manner. The complex and very broad scope of its biodiversity objectives and the offshore areas of the Union's marine waters, sometimes extending up to 350 nautical miles out from the coast and to depths of over 5000m, present particularly challenging aspects. There remain many scientific uncertainties, especially to fully understand the relationships between anthropogenic pressures and their impacts on the marine environment, and on how the ecosystems will respond to particular management actions. In addition, there are many aspects where data and monitoring systems are not sufficiently developed or lack sufficient time series, giving uncertainties in how best to implement the Directive. The overall goal of the Directive, good environmental status, is expressed in high-level terms in the Article 3(5) definition and through the eleven descriptors of MSFD Annex I. These provide for a potentially very wide need for monitoring and assessment, particularly concerning biodiversity, food webs and sea-floor integrity (Descriptors 1, 4 and 6) and especially for those Member States where the marine waters are very extensive. The assessment of the current state of marine waters is important for assessing the degree of risk to achieving GES (how far the marine waters are from GES) and the risk of status deteriorating from GES to a sub GES level; the determination of GES thus provides the benchmark against which to assess the degree of risk. With this reasoning, the implementation of the Directive can be most effective when it is clearly focused on reducing the anthropogenic pressures which are considered to be, or likely to be, adversely affecting environmental status in each region or subregion, and on assessing the nature and scale of associated environmental impacts. With this approach, attention is drawn towards assessing the scale of the pressures and their impacts on particular aspects of the marine environment, rather than attempting to monitor and assess every possible aspect of the environment in all areas of marine waters. Such an approach can allow the majority of resources in Member States to be focused on those issues which can make the biggest contribution towards achieving GES, with fewer resources focused on lesser issues (pressures) and wider surveillance of the marine environment. The latter is however important in the role of monitoring ‘unimpacted’ areas and wider ecosystem changes, which help in understanding monitoring results that are focused on specific pressures and impacted ecosystem elements and areas. At the same time, the mechanisms for Member States to achieve GES lie primarily in the control of the anthropogenic pressures which are causing adverse effects on the marine environment and hence preventing the achievement of GES. Most management approaches (measures) anticipate passive recovery of the marine ecosystem following a reduction in pressure levels. Measures tend to mostly focus on reducing or eliminating the new input of the pressure to the marine environment, whilst some actively aim to reduce/remove the existing pressure once in the marine environment (e.g. removal of litter). The alternative management mechanism, that of direct intervention to improve the status of the marine environment (such as active restoration of species, habitats and areas), is unlikely to be possible or cost-efficient in other than a minority of situations. Both of these approaches are delivered via the programmes of measures. The use of risk-based approaches can thus play an important part in the delivery of the Directive, allowing a focus on those aspects (pressures, impacts, areas and activities) which provide most risk to Member State’s achievement or maintenance of GES. Refer to section 7 for more specific information on application of risk-based approaches. 4.5.Steps in a prioritised implementation process The following provides a generalised step-wise approach to a prioritised implementation of the Directive: a.Map the distribution and intensity of uses and human activities (identifies main areas of activity, potential for use as proxy pressure assessment, supports later identification of measures). This approach is most relevant for sea-based activities, especially those on or affecting the seabed, but is also relevant for fishing and shipping activities (with regard to fishing and underwater noise pressures); b.Assess the pressures – spatial distribution and intensity (and temporal aspects, where necessary) of each pressure, identifying those which are of greatest concern; this may be somewhat less relevant for assessments of mobile species such as birds, seals and cetaceans, as these can be wide-ranging and thus more difficult to know where and when they are exposed to particular pressures; c.Identify those aspects of the marine environment (species, habitats, ecosystem functions and processes) and areas most (likely to be) affected by these pressures; d.Assess the environmental impacts – extent of impacts in relation to the elements to be used for the state-based and the pressure assessments; focus monitoring and assessment on these aspects (e.g. species, habitats, ecosystem functions and processes) and areas which are considered to be most at risk of adverse effects (environmental impact). Monitoring focused on the boundary zone between ‘good status’ and ‘not good status’, may help reduced efforts in areas where status is known to be good or known to be poor. This more limited monitoring in areas of good status however provides important reference data with which to compare the impacted areas and any change in status over time (including both continued improvements in status or signs of deterioration in status which could risk leading to a sub GES status); e.Assess the state – bringing together the relevant assessments of impacts from point (d) to lead to an overall assessment of current status; f.Direct management responses (measures) towards those pressures and areas which are considered to be causing the greatest adverse effects (in terms of intensity and/or extent) and contributing most to any failure to achieve GES. 5.An integrated process to determination of GES and its assessment The intricate link between Articles 8 and 9 and with the GES Decision (section 3.4 and 3.5, Figure 5) indicates a need to structure both assessment and determination in a mutually compatible way. Assessments are on specified topics (elements) in defined parts of marine (sub)regions/marine waters (Marine Reporting Units – see section 5.4) and should give a clear expression of the extent to which GES has been achieved in each area. This structuring is shaped by MSFD Annex I (i.e. the descriptors) and the requirements of Article 8(1) (particularly Article 8(1)(a) and (1)(b)), and supported by MSFD Annex III and the GES Decision, the latter indicating how to express the extent to which GES has been achieved. 5.1.GES Decision supports an integrated process Key message The pressure-based descriptors can be assessed as predominant pressures and their impacts to contribute to the needs of Article 8(1)(b) and should, where possible, provide an assessment of impacts which is directly relevant to assessments of ecosystem elements under Article 8(1)(a).

The state-based descriptors can be assessed as specified elements of marine ecosystems (e.g. birds, mammals, seabed habitats) to fulfil the needs of Article 8(1)(a), reflecting the impacts upon each state element from all the (predominant) pressures to which each is subject (from the pressures assessed under Article 8(1)(b)). This structured approach provides clarity on how to assess the extent to which GES is achieved, and is supported by the structure of the GES Decision. To support this connection, the scales of assessment and the ecosystem elements used under Article 8(1)(a) and (1)(b) should be compatible. The eleven GES descriptors and their separate treatment in Decision 2010/477/EU (now repealed) fostered processes for MSFD implementation in the first cycle which typically maintained the descriptors in ‘silos’ without a strong integration that reflects their inter-connectedness and the ecosystem-based approach which is sought in Article 1(3). The revised GES Decision has been structured and specified to facilitate a more integrated approach to the determination and assessment of GES, as described in section 3.3.4. The assessment (Article 8(1)) and the descriptors (section 3.3.2) fall into two broad themes: a.Assessments of pressures and their impacts - Article 8(1)(b), Descriptors 2, 5, 8, 9, 10 and 11, together with the additional main pressures of MSFD Annex III Table 2a: ‘extraction of wild species’ (Descriptor 3), ‘physical disturbance’ (Descriptor 6), ‘physical loss’ and associated ‘hydrological changes’ (Descriptors 6 and 7). The other pressures listed in MSFD Annex III Table 2a should be assessed where relevant; b.Assessments of ecosystem state – Article 8(1)(a); the main elements of marine ecosystems from MSFD Annex III Table 1 (birds, mammals, reptiles, fish and cephalopods, and pelagic and benthic habitats including their biological communities) structure the state-based assessments, integrating the state-based Descriptors 1, 3, 4 and 6. These elements are complemented by a whole ecosystem perspective, reflected by structure and functional aspects of Descriptors 1 and 4. Figure 8 illustrates how these two broad themes can be organised. Article 8(1)(b) is undertaken as a set of pressure-impact assessments ('satellites'), with the outcomes concerning impacts being used to feed into assessments of a specified set of ecosystem elements for Article 8(1)(a) (‘pizza slices’). This approach has the following benefits: a.Achievement of the goals of the Directive is not encompassed within a single overall assessment, but spread over a number of defined components, allowing the achievement of GES to be measured as a set of smaller goals, which together contribute to the overall goal laid down in Article 1(1), thereby allowing progress towards GES to be expressed in a more tangible manner; b.Focusing on a specific set of assessments provides a way of dividing the complexity of marine ecosystems in each (sub)region into a set of more manageable units for monitoring, assessment, target setting and measures; c.It brings structure and functional aspects of ecosystems together at an appropriate resolution (i.e. within each main ecosystem element rather than only at the whole ecosystem level); this overcomes some of the inherent overlaps between the descriptors (e.g. benthic habitats under D1 and sea-floor integrity under D6; ecosystems under D1 and food-webs under D4); d.It relates more readily to practical monitoring and assessment processes (e.g. monitoring of birds, mammals and fish is typically undertaken separately using different techniques); e.It links more effectively to management needs, relating more specifically to pressures and human activities which can be managed in specified areas in order to achieve GES; f.It provides an indication of whether there is need for particular (additional) environmental targets under Article 10 and (additional) measures under Article 13 in order to reach GES (bearing in mind that in some cases all necessary targets and measures may have been put in place but the ecosystem may not yet have reached GES due to slow response times); g.It provides an important means to express to stakeholders and the public the progress being made in implementation of the Directive and achievement of its overall goals. Whilst this structure (Figure 8) has these practical advantages, this compartmentalisation may mask some elements of an ecosystem-based approach; these could be addressed by more holistic assessments of ecosystem structure and functions (including food webs). Based on the structure of the GES Decision and the criteria, the interrelationships between the relevant parts of Article 8, the MSFD Annex I Descriptors, the ecosystem elements and pressures of MSFD Annex III, and the criteria in the GES Decision are illustrated in the framework for assessment shown in Figure 9.

This framework leads to two sets of assessments, as shown in Figure 8: a.A set of pressure-impact assessments under Article 8(1)(b) and the pressure-based descriptors (columns in Figure 9). These assess impacts in a way which relates directly to the ecosystem state elements being assessed under Article 8(1)(a), and to provide outcomes which are directly useful for the state-based assessments. For example, for the assessment of impact on non-commercial species, incidental by-catch needs to be separated into at least the specified species groups of birds, mammals, reptiles and fish and preferably at species level, in order to feed into species-level assessments under D1. b.A set of ecosystem element assessments under Article 8(1)(a) and the state-based descriptors (rows in Figure 9). These state-based assessments reflect the impacts upon each state element from all the (predominant) pressures to which each is subject. For example, assessment of a benthic habitat should encompass, where appropriate, the impact assessments from the pressures: physical loss, physical disturbance, non-indigenous species, nutrient enrichment, removal of species and, if appropriate, other pressures. This framework facilitates assessment of cumulative effects of multiple pressures on the ecosystem elements, whereby the impacts assessed under individual pressures (Article 8(1)(b)) can be considered collectively for the assessments of each element under Article 8(1)(a). 5.2.Main steps in the assessment and determination process Within the overall approach for implementation outlined in section 4, it is necessary to define the particular ways in which the pressures, impacts and state elements are to be assessed in each (sub)region under Article 8(1)(a) and 8(1)(b), and to determine the extent to which these assessments indicate whether GES as determined under Article 9(1) has been achieved. This requires an iterative process, as illustrated in Figure 5, between the assessments and the determination of GES. This can be considered in a number of stages which should lead to an operational framework to meet the requirements of Articles 8 and 9 at the level required for reporting, as specified in the GES Decision and associated CIS reporting guidance: a.Define the elements for assessment, based on the requirements of the GES Decision and MSFD Annex III and adjusted to the main pressures and ecosystem elements present in the (sub)region. This should consider the need to use the outcomes of the pressure-impact assessments to contribute to the state assessments. The elements should reflect both the range of ecosystem characteristics in each (sub)region and the main pressures affecting or potentially affecting their environmental status, and can be selected on a risk-based approach (section 5.3); b.Define the scales for each assessment, as the reporting areas (MRUs), as these can strongly influence the outcomes of the assessments (section 5.4); c.Identify the GES criteria to be used for each of the elements, including possible deselection of primary criteria and selection of secondary criteria; in some cases, this step is undertaken prior to step (a), e.g. for D2, D5, D10 (section 5.5); d.Define how each criterion will be assessed, based on the data to be used (from Article 11 monitoring programmes or other sources) and how it will be processed, including its spatial and temporal aggregation within the MRU. This process is often described as a scientific indicator which provides a suitable dataset (often as a time-series or as a spatial distribution map) for the criterion (section 5.5); e.Where required by the GES Decision, determine a threshold value for the criterion/element, based on an associated reference condition; if such values are not yet available, it may be possible to indicate any change in status (trend) compared with previous reporting (section 5.7); f.Use the outcomes of the criterion assessment as specified by the GES Decision: to either express the extent to which GES has been achieved or to contribute the outcome to a state-based assessment. In some cases, this requires an integration of the criteria per element (species D1, D3, habitats D6), species group (D1) or descriptor (e.g. D5, D10, D11) (section 5.10); g.Report on the assessment outcomes (extent to which GES has been achieved) and associated specific characteristics of GES (elements, threshold values, proportion values) using the Article 8 reporting schema (section 5.11); h.Update, if necessary, the more general (descriptive) determination of GES, at descriptor and/or criterion level, to reflect the specific determination of GES resulting from steps a-g, using the Article 9 reporting schema (section 5.11). Within this overall framework (Figures 8 and 9), the GES Decision sets out more specific requirements for expressing the extent to which GES has been achieved (section 5.10), for example as a set of species group and broad habitat type assessments (section 5.3) and where criteria for particular descriptors should be integrated at descriptor level or used to contribute to the assessment of another descriptor. 5.3.Elements for assessment of progress towards GES Section 3.3 and Figure 4 outline that elements for assessment of progress towards GES are progressively defined from the broad topics provided in MSFD Annex III to finer topics in Article 9(1), via the elements which are specified in the GES Decision. This hierarchical approach provides both consistency and flexibility, accommodating the need for coherent approaches at Union and regional levels whilst also reflecting the differences in characteristics at (sub)regional and national levels. For each Descriptor, the GES Decision makes clear the elements to be assessed and the scale of assessment, such that use of the criteria should lead to assessments per element per assessment area (MRU); in a number of cases these elements need to be further specified at (sub)regional level. 5.3.1.Elements for Article 8(1)(b) assessments: pressures and impacts

A set of pressures on the marine environment is provided in MSFD Annex III Table 2a. Criteria in the GES Decision address a number of these for the pressure-based descriptors and other key pressures (extraction of species, physical disturbance, physical loss), together with associated impact criteria (Table 3). Other pressures (listed in MSFD Annex III Table 2a) should also be assessed where they cause risk to the species, habitats and ecosystems of a (sub)region. The selection of pressure elements (and criteria) to be assessed in each (sub)region may follow a risk-based approach (section 7). MSFD Annex III Table 2a GES Decision Article 9(1) Determination of GES Theme Pressure Criteria elements (pressures) Criteria elements (impacts) Elements Biological Input or spread of non-indigenous species D2C1 - Newly-introduced NIS D2C2 - Established NIS D2C3 - Species groups and broad habitat types at risk Primary criteria: criteria elements relevant to (sub)region Secondary criteria: criteria elements at risk in (sub)region Pressures without GES Decision criteria: where relevant (causing risk) for (sub)regional species, habitats and ecosystems Criteria elements for impact assessments should, where possible, be relevant to the elements used for D1, D3, D4 and D6. Input of microbial pathogens Input of genetically modified species and translocation of native species Loss of, or change to, natural biological communities due to cultivation of animal or plant species Disturbance of species (e.g. where they breed, rest and feed) due to human presence Extraction of, or mortality/injury to, wild species (by commercial and recreational fishing and other activities) D3 – commercially-exploited fish and shellfish D3C1 - commercially-exploited fish and shellfish D1C1 – incidentally by-caught species at risk Physical Physical disturbance to seabed (temporary or reversible) D6C2 – Physical disturbance to seabed D6C3 – Benthic broad habitat types used for D1/D6 Physical loss (due to permanent change of seabed substrate or morphology and to extraction of seabed substrate) D6C1 – Physical loss of seabed Changes to hydrological conditions D7C1 – Alteration of hydrographical conditions of the seabed and water column D7C2 – Benthic broad habitat types used for D1/D6 Substances, litter and energy Input of nutrients – diffuse sources, point sources, atmospheric deposition D5C1 – Nutrients (DIN, TN, DIP, TP) D5C2-D5C3-D5C4-D5C5-D5C6-D5C7-D5C8 – Chlorophyll-a, harmful algal blooms, photic limit, dissolved oxygen, opportunistic macroalgae, macrophyte and macrofaunal communities Input of organic matter – diffuse sources and point sources D5C8 - macrofaunal communities Input of other substances (e.g. synthetic substances, non-synthetic substances, radionuclides) – diffuse sources, point sources, atmospheric deposition, acute events D8C1 – contaminants from WFD and other contaminants which may give rise to pollution effects D8C3 – acute pollution events D9C1 – contaminants in food regulation; additional contaminants D8C2 – species and habitats at risk D8C4 – species of species groups and benthic broad habitats Input of litter (solid waste matter, including micro-sized litter) D10C1 - litter (10 categories) D10C2-D10C3 – micro-litter (2 categories) D10C4 - species at risk Input of anthropogenic sound (impulsive, continuous) D11C1 – anthropogenic impulsive sound D11C2 – anthropogenic continuous low-frequency sound Input of other forms of energy (including electromagnetic fields, light and heat) Input of water – point sources (e.g. brine) 5.3.2.Elements for Article 8(1)(a) assessments: ecosystem structure, functions and processes The set of ecosystem elements shown in Figure 8 is based on the structural elements of marine ecosystems provided in MSFD Annex III Table 1 and the set of species groups and pelagic and benthic broad habitat types, including their biological communities, provided in the GES Decision (Tables 4 and 5). MSFD Annex III Table 1 GES Decision Table 1 Article 9(1) Determination of GES Theme Ecosystem elements Species groups Elements Species Birds Grazing birds Species groups relevant for the (sub)region Specific species per species group (selected according to the scientific and practical criteria in the GES Decision) Wading birds Surface-feeding birds Pelagic-feeding birds Benthic-feeding birds Mammals Small toothed cetaceans Deep-diving toothed cetaceans Baleen whales Seals Reptiles Turtles Fish Coastal fish Pelagic shelf fish Demersal shelf fish Deep-sea fish Cephalopods Coastal/shelf cephalopods Deep-sea cephalopods MSFD Annex III Table 1 GES Decision Table 2 Article 9(1) Determination of GES Theme Ecosystem elements Broad habitat types Elements Habitats Pelagic broad habitats Variable salinity Coastal Shelf Oceanic/beyond shelf Broad habitat types relevant for the (sub)region Other habitat types (e.g. from Habitats Directive, RSCs, EUNIS levels 4-6), selected according to the scientific and practical criteria in the GES Decision, which are used for assessment of the broad habitat type (criterion D6C5) and/or for assessment in their own right Benthic broad habitats Littoral rock and biogenic reef Littoral sediment Infralittoral rock and biogenic reef Infralittoral coarse sediment Infralittoral mixed sediment Infralittoral sand Infralittoral mud Circalittoral rock and biogenic reef Circalittoral coarse sediment Circalittoral mixed sediment Circalittoral sand Circalittoral mud Offshore circalittoral rock and biogenic reef Offshore circalittoral coarse sediment Offshore circalittoral mixed sediment Offshore circalittoral sand Offshore circalittoral mud Upper bathyal rock and biogenic reef Upper bathyal sediment Lower bathyal rock and biogenic reef Lower bathyal sediment Abyssal Other habitat types - For Article 9(1), the set of species groups and broad habitat types needs to be adjusted (reduced) to those types which are present in each (sub)region. The GES Decision indicates that each species group should be represented by a set of species and provides selection criteria for this purpose. Similarly, the assessment of each broad habitat type can be supported by assessments of specified sub-types, according to these selection criteria, although the broad habitat types can also be assessed directly. The selection criteria aim to ensure both representivity of the ecosystem component and risk from the main pressures. At the ecosystem level, and as indicated in the GES Decision, a set of at least three trophic guilds should be selected, based on the selection criteria provided in the GES Decision. Ecosystems in this context should be considered as broad-scale parts of a region or subregion, each encompassing a set of species groups and broad habitat types. It might be appropriate to consider coastal, shelf and open ocean/deep sea zones separately. The definition of GES refers to ecosystem functions and processes; these are only partly addressed via the trophic guilds to be included under D4 (food webs) and may therefore need further specification. 5.4.Scales of assessment and assessment/reporting areas This section deals specifically with scales for assessment and reporting of current environmental status under Article 8. Scales for other aspects of MSFD implementation may differ: for example, the setting of environmental targets could be at national level, linked to national implementation of measures. And the implementation of monitoring programmes can be organised at various scales, depending on the monitoring methods and organisational needs. For both monitoring and assessment, the Directive seeks consistency across each (sub)region in the methods used (Article 11(2) and 11(4)); thus the methods could be agreed at (sub)regional level, but delivered at national or even subnational scales. In other cases, international monitoring programmes, such as for mammals and fisheries, are undertaken. It is clear from the Directive that GES must be determined at a (sub)regional scale (Article 3(5)). However, assessments of whether GES has been achieved can be at a finer scale, as provided in the GES Decision. The broad range of topics to be assessed across the eleven descriptors calls for a variety of scales to be used as part of an ecosystem-based delivery of the Directive. For example, wide-ranging species such as baleen whales are more appropriately assessed at the regional scale, whilst nutrient enrichment and litter may be more appropriately assessed at finer scales linked to their land-based sources and management needs. Also, there may be several populations of particular species (e.g. commercial fish) in a region and subregion; each should typically be assessed separately. A variety of assessment scales are therefore necessary to reflect: a.Ecologically-relevant scales for the various ecosystem elements (species, habitats, ecosystems); b.Management and administratively-relevant scales for pressure elements, bearing in mind the need to link impacts from such pressures to the scales used for those impacted elements. Additionally, the outcome of the assessment, i.e. whether GES has been achieved, is intrinsically linked to the scale of assessment. For example, assessing pressures and their impacts at too broad a scale can mask significant areas of impact in certain parts of a region or subregion and render the Directive ineffective. On the other hand, the Directive must be applied across the entire area of marine waters and adoption of too fine a scale for assessments could lead to burdensome assessment processes.

The GES Decision sets out a generic set of scales to be used for assessment of each descriptor, criterion or element, applicable across all marine regions. Table 6 summarises the scales for assessment in the GES Decision, in which scales for particular pressures are linked to the state elements for which they are most relevant (e.g. extraction of fish and fish stock assessments, physical disturbance and benthic habitats, underwater noise and cetaceans). Elements for assessment Region Subregion Subdivision

(of region or subregion) National part of subdivision Coastal waters (WFD) Pressure elements Pressure criteria Non-indigenous species (D2) C1, C2 Nutrient enrichment (D5) C1 (beyond WFD coastal waters) C1: as WFD Physical loss and disturbance (D6) C1, C2: as used for broad habitat types under D1 and D6 Hydrographical conditions (D7) C1: as used for broad habitat types under D1 and D6 Contaminants (D8) C3 (divided by national borders, where needed) C1 (beyond WFD territorial waters) C1: as WFD (to 12nm) Contaminants in seafood (D9) C1: catch or production areas of Reg. No 1379/2013 Litter (D10) C1, C2, C3 Underwater noise (D11) C1, C2 Impact elements Impact (adverse effect) criteria D1 (incidental by-catch) C1: as used for species groups under D1C2-D1C5 D2 C3: as used for corresponding species groups and broad habitat types under D1 and D6 D3 C1: ecologically-relevant scales for each population, based on ICES, GFCM and FAO areas Nutrient enrichment (D5) C2-C8 (beyond WFD coastal waters) C2-C8: As WFD Physical loss and disturbance (D6) C3: as used for broad habitat types under D1 and D6 Hydrographical conditions (D7) C2: as used for broad habitat types under D1 and D6 Contaminants (D8) C2 (beyond WFD territorial waters) C2: as WFD (to 12nm) C4: as used for species groups and broad habitat types under D1 and D6 D10 (Litter) C4: as used for species groups under D1 State elements Species groups (D1): Birds Baltic & Black Sea regions or subdivisions: all groups NE Atlantic & Mediterranean: all groups Species groups (D1): Mammals Deep-diving toothed cetaceans, baleen whales. Baltic & Black Sea regions or subdivisions: small toothed cetaceans, seals (latter not present in Black Sea) NE Atlantic & Mediterranean: small toothed cetaceans, seals Species groups (D1): Reptiles Turtles Species groups (D1): Fish (excepting commercial species - see D3) Deep-sea fish Baltic & Black Sea regions or subdivisions: pelagic & demersal fish NE Atlantic & Mediterranean: pelagic & demersal fish Coastal fish Species groups (D1): Cephalopods (excepting commercial species - see D3) Baltic & Black Sea regions or subdivisions: all groups NE Atlantic & Mediterranean: all groups Commercial fish and shellfish (D3) C2, C3: ecologically-relevant scales, based on ICES, GFCM and FAO areas (same as C1) Pelagic and benthic habitats (D1, 6) Biogeographically-relevant scales Ecosystems/food webs (D1/D4) Baltic & Black Sea NE Atlantic & Mediterranean Figure 10 illustrates these scales in a nested way, such that all finer scales sit within a broader scale, thereby allowing aggregation up to subregional and regional scales. This generic scheme needs adaptation to meet the operational requirements of each region and subregion. From this definition of the scale of assessment to be used comes the need to define the specific areas of each region or subregion to which each assessment applies and for which the extent to which GES has been achieved is reported. These have been termed the Marine Reporting Units (MRU), each being the area over which a judgement is made on whether GES has been achieved for a specified element or Descriptor. Within a single MRU, there may be multiple observations, of relevant parameters (e.g. in point, transect or grid type monitoring) over specified timeframes, which are aggregated to conclude on the extent to which GES has been achieved. Given the number of different assessments to be undertaken, there is potential to develop a complex unconnected set of MRUs which may lead to confusion in their use (e.g. presentation of assessments, communication to stakeholders). The following approach is therefore considered most logical: a.use a nested system of MRUs, based on the same set of smallest areas and aggregating these where needed; b.minimise the number of areas defined, e.g. by using the same areas for several species groups, pelagic and benthic habitats. This can still respect the need for ecologically-relevant scales as the characteristics of water masses influence species composition in the pelagic and benthic habitats and associated mobile species; c.ensure as far as possible that the state and pressure-based assessments are compatible, in terms of scales of assessment and resolution of the ecosystem elements which are assessed under state (Article 8(1)(a)) and as impacts (Article 8(1)(b)) (section 5.3 and 5.4); d.associate the areas used for pressure-based and ecosystem-based assessments to each other (e.g. areas for assessment of physical disturbance are the same as used for the assessment of seabed habitats or nested within the area). The following boundaries for a nested system of MRUs are already defined: a.marine regions (Figure 2) b.marine subregions (Figure 2) c.national borders d.WFD coastal and territorial waters (for D5 and D8 assessments) This leaves the main consideration as to whether there is need to subdivide each (sub)region into a suitable (and preferably low) number of subdivisions. Article 3(2) provides criteria which are relevant for defining subdivisions (namely, hydrological, oceanographic and biogeographic features). Additionally, some Member States have used the provisions of Article 4(2) to define national subdivisions. Whilst an outline approach to defining and using such a nested system is presented here, it is necessary for Member States, working together in each region, to develop this into an operational mechanism. This has already been achieved for the Baltic Sea region by HELCOM (Figure 11); similar systems are under development by other RSCs.

5.5.Identifying the GES criteria to be used and how they are assessed The GES Decision provides a set of criteria to be used for each descriptor, distinguishing those which must be used (primary) from those which Member States may choose to use, based mainly on risk (secondary). The GES Decision has provision for the primary criteria to not be used in certain situations. The selection of criteria is often considered in conjunction with selecting the elements to be assessed, particularly for some descriptors: D2, D4, D5, D7 (for C1), D8 (for C2) and D10. However, the GES determination and assessments are focused on the elements (being components of the marine ecosystem or pressures upon it) and the criteria (used singly or in combination) are there to provide a means to assess the quality of the element rather than being the end point of the assessment itself. The majority of criteria assessments depend on data collected from the Article 11 monitoring programmes for MSFD purposes or available from other sources (e.g. satellite data from Copernicus, or pressure data derived from human activity data, such as Vessel Monitoring System data for fishing vessels or Automatic Identification System data for ships). In a minority of cases a more qualitative approach may be appropriate (e.g. assessment of habitat quality for species D1C5). The use of data, whether from direct observations or modelled, enables robust assessment of the criterion, allowing a clear means to assess current status and to follow changes both spatially and over time. The robustness of such assessments is further enhanced when the data are processed according to methods agreed across the countries of each (sub)region, as required by Article 11(2) and 11(4). The ongoing processes of (sub)regional cooperation in the RCSs or between Member States (e.g. in the Black Sea region and Macaronesia subregion) are leading to data-driven indicators which serve this purpose. 5.6.Determining GES: criteria on quality, proportion, distribution and duration Key message Determinations of GES set, whenever possible, both the quality of the pressure, impact and state elements that is to be achieved and the proportion of the element that should achieve such quality levels. This ensures that the assessment concludes on whether GES has been achieved or not in a particular assessment area. The GES Decision sets out the criteria to be used and how to express the extent to which GES has been achieved for each descriptor. These can be categorised into four principle types: a.Quality: the quality to be achieved for each element assessed, which is expressed as a threshold value, whether it is a state element, a pressure or its impacts (e.g. contaminant concentration, condition of a habitat in relation to a particular pressure, age and size structure of a population). This quality level can be assessed at any given location within an MRU and can vary across the MRU. b.Proportion: the proportion of certain criteria elements (e.g. populations of species, habitats) that should achieve those quality threshold values. This includes criteria related to population size and mortality rates (e.g. spawning stock biomass (SSB) and fishing mortality (F) for commercial fish) and benthic habitat criteria that include thresholds for the proportion of allowable habitat loss and proportion of habitat to achieve an acceptable condition. c.Distribution: the distribution of certain pressures, for instance to avoid certain sensitive areas for species, or impacts; d.Duration: the duration of certain pressures, such as to avoid particular pressures at sensitive periods for species, or impacts. The GES Decision criteria are allocated to one or several of these four types in Table 7, which also indicates where threshold values for the GES criteria need to be set (see section 5.7). Type Pressure criteria Impact criteria State criteria Quality D2C1 D5C1 D8C1 D9C1 D10C1p, C2p, C3 D11C1p, C2p D2C3 D5C2, C3p, C4, C5, C6, C7p, C8 D6C3 D7C2 D8C2 D10C4 D1C3, C6 D3C3 D6C5p D4C1, C2, C3, C4 Proportion D1C1 D3C1 D5C3p D1C2 D3C2 D6C4, C5p Distribution D10C1p, C2p D11C1p, C2p D5C7p D1C4 Duration D11C1p, C2p D5C3p No threshold value requested (criterion contributes to other assessments) D2C2 D6C1, C2 D7C1 D8C3 D7C2 D8C4 D1C5 Most criteria do not express the proportion of the assessment area, or of a species population or habitat type in the assessment area, over which the defined quality threshold value should be achieved. Where it is not explicit in the criterion, such proportion values should be expressed as part of the determination of GES under Article 9(1) (GES Decision Recital 16). For certain descriptors, the aspect of distribution (e.g. of species) or duration (e.g. of underwater noise) is also relevant for the GES determination. Figure 12 provides a generic depiction of the relationship between quality and proportion. Some worked examples are provided in Annex 2. The quality of a particular element can vary across an MRU, leading to areas where the quality is above the threshold value and areas where it is below the threshold value. For a population of a species, there can be parts of the population in good health, whilst other parts are not. From Figure 12 and the examples in Annex 2, it can be seen that defining the proportion of the MRU (including of a population for species assessments) that needs to achieve the quality threshold value is an important aspect of the GES determination. There may be cases where some parts of the MRU are below the quality threshold value, but the extent of this is considered acceptable (i.e. as defined through the Article 9(1) GES determination) in relation to the objectives for GES (for example the long-term viability of a species population).

The quality threshold value is typically set on scientific grounds in relation to the degree of change in quality (deviation from reference condition; see section 5.7) that can be tolerated before the element is considered to be adversely affected (impacted). For pressures, this represents the level of pressure that would give rise to such adverse effects. The proportion value set for population levels and mortality rates for species is typically set on a scientific basis in relation to their long-term viability. Determinations of GES must be clear about both aspects (quality and extent/proportion) so that after assessment it is clear whether GES has been achieved or not. This can also be important in giving clear boundaries within which industry can operate, allowing for sustainable uses of the sea, especially where the industry exerts certain pressures and impacts on the environment. 5.7.