• Latest Version, 2024 Assessment
• 2018 assessment

Eutrophication

The extent to which Good Environmental Status has been achieved

Good Environmental Status (GES) has been achieved for Eutrophication (D5). An integration of indicators for both offshore and inshore eutrophication assessments shows the majority (95%) of UK coastal, shelf and oceanic areas are found to be at GES (see Figure 1).  

However, 3% of coastal waterbodies have not achieved GES, with a further 2% achieving only partial GES. This is due to current levels of the nutrient indicator exceeding GES thresholds, giving a higher risk of not achieving GES into the future. In addition, nutrient loading into UK sea areas is increasingly imbalanced, resulting in potentially detrimental mismatches of nitrogen and phosphorus concentrations in UK river-influenced marine waters.

               

Figure 1: Maps displaying the outcomes of the eutrophication assessment using assessments for (a) Water Framework Directive (WFD) (known as Water Environment Regulations (WER) for England and Wales) coastal waterbodies and OSPAR UK assessment areas and (b) WFD/WER waterbodies only.  For the WFD/WER coastal waterbodies, the eutrophication assessment is taken from a “one out all out” (OOAO) approach - the WFD/WER waterbody classification is a combination of many different elements combined using a OOAO approach to overall/ecological status classification, where the lowest performing element drives the overall/ecological classification. The indicators within the OOAO are indicators that are related to eutrophication, including phytoplankton (combining the outcomes of growing season chlorophyll and phytoplankton abundance indicators), opportunistic macroalgae and dissolved oxygen. Macroalgal element only refers to opportunistic macroalgae here, whereas typically WFD/WER use all macroalgal tools for assessing eutrophication including the Intertidal Rocky Shore Macroalgal Index as well as the Opportunistic Macroalgal Blooming Tool. Waterbodies are also designated as being at risk of future failures if they fail dissolved nutrients only. OSPAR assessment areas for the UK were classified using the OSPAR Common Procedure (COMP) 4 methodology (described in ​Devlin and others, 2023a). The OSPAR eutrophication assessment is based on a combination of two common indicators. The lowest score of the growing season mean chlorophyll indicator and the 5th percentile bottom dissolved oxygen indicator from the score for the overall assessment. Under the OSPAR assessment, dissolved nutrients are reported but do not influence the final overall eutrophication assessment, however they will be identified at risk of future failure. Data for the OSPAR assessment is taken from 2015 to 2020. (Exclusive Economic Zone (EEZ) as taken from “Flanders Marine Institute (2019). Maritime Boundaries Geodatabase: Maritime Boundaries and EEZ (200NM), version 11. Available online at https://doi.org/10.14284/386”)

Progress since previous assessments

Generally, the eutrophication status of coastal, shelf and oceanic areas has not deteriorated since the last assessment (2015) when they were also assessed as largely achieving GES (Figure 2). However, 3% of coastal (within 1 – 3nm) waterbodies have not achieved GES, and increasing trends for nutrients and chlorophyll for many of the plume and coastal waters suggest a deterioration of water quality (see Figure 2). Bottom water dissolved oxygen concentrations remain high enough to be classified as achieving GES for the UK river plumes and Coastal UK assessment areas, but the dissolved oxygen (DO) status is trending away from GES (decreasing oxygen concentrations). In addition, trends in nutrient loads indicate that 11 of the 39 reporting areas are showing an increasing trend for nitrate (note only in 4 of the 39 areas is this increase deemed statistically significant), with 2 of 39 (not significant) showing increasing trends for phosphate.   

Figure 2: Two graphs showing a summary of trends (left) and data availability (right) in assessed concentrations from 1990-2020 for all OSPAR assessment areas fully or partially within the UK Exclusive Economic Zone (EEZ). Where data were available for at last 5 years, Mann-Kendall analysis was caried out to detect trends, size of the triangles in (a) is scaled to the value of Kendall’s rank coefficient, quantifies monotonic trends in timeseries data, where -1 is consistent decrease and +1 is consistent increase based on comparing each year’s value to all preceding years. Red upwards-facing triangles indicate trends towards, or of, increased exceedance of assessment threshold values (increasing concentrations for nutrients and chlorophyll, decreasing concentrations for oxygen) while blue downwards-facing triangles indicate trends towards reaching assessment thresholds or away from potentially exceeding (decreasing concentrations for nutrients and chlorophyll, increasing concentrations for oxygen). Triangles with black outlines indicate statistically significant (p<0.05) trends.  Black circles indicate missing values (insufficient data for trend analysis). DIN = dissolved inorganic nitrogen, DIP = dissolved inorganic phosphorous, chl-a = chlorophyll-a, DO = dissolved oxygen. Explanation of codes to the OSPAR Waterbody names (on left axis of plots) can be found in The Common Procedure for the Identification of the Eutrophication Status of the OSPAR Maritime Area.   

How progress has been assessed

Assessment overview

Reporting is based on the OSPAR common indicators (2015-2020) reported for the Eutrophication Thematic Assessment report under the OSPAR Quality Status Report (QSR) 2023, alongside outcomes of the Water Framework Directive (WFD) (now known as Water Environment Regulations (WER) for England and Wales only) assessments for coastal waterbodies (2014-2019). An overview of the assessment status for the four existing criteria, associated targets, and indicators is provided in Table 1. 

There are three indicators overall; multi-metric (for WER/WFD) and chlorophyll ‘a' concentration (for OSPAR); dissolved oxygen levels; and winter dissolved inorganic nitrogen (DIN) levels. There are other eutrophication indicators not considered here, but that should be for future assessments.

Table 1. Summary overview of the status assessment for all Eutrophication (D5) indicator assessments

Criteria 1	Nutrient concentrations
2019 Target	Nutrient concentrations are below the levels which could lead to harmful eutrophication effects.
Indicator	Nutrients (DIN)
Greater North Sea	Partially met
Celtic Seas	Partially met
Criteria 2	Chlorophyll-a concentrations
2019 Target	Chlorophyll-a concentrations are below levels which could lead to harmful eutrophication effects.
Indicator	Phytoplankton (a multi- metric of chlorophyll-a and plankton abundance).
Greater North Sea	Partially met
Celtic Seas	Partially met
Criteria 3	Dissolved Oxygen content
2019 Target	Dissolved oxygen content in coastal waters are above levels which could lead to harmful eutrophication effects.
Indicator	Dissolved oxygen
Greater North Sea	Met
Celtic Seas	Met

Detailed assessments

The OSPAR QSR 2023 is based on newly agreed ecologically relevant assessment areas defined by oceanographic criteria, and harmonised thresholds for eutrophication parameters which have been derived primarily from an ensemble modelling approach (Heyden and Leujak, 2022; Prins and Enserink, 2022; Devlin and others, 2023b). The OSPAR assessment areas include riverine plume areas, coastal areas and oceanic areas. WFD/WER assessments cover coastal waters up to 1 nm from the coast for England, Wales and Northern Ireland and 3 nm for Scotland (Figure 1, Table 2). Outcomes for the common indicators assessed under the OSPAR Eutrophication Thematic Assessment (2015-2020) were used to assess GES in 2024 for the UK coastal and offshore waters (ICES, 2022). Outcomes from the WFD/WER assessments carried out for Wales, Scotland, England and Northern Ireland were used to assess GES in 2024 for UK transitional and coastal waters (Anon, 2022; Anon 2023; Anon 2024a, 2024b). Both the WFD/WER and OSPAR classify the eutrophication status of waters using a suite of eutrophication related indicators to provide their final assessment. Whilst these indicators are broadly comparable across the two assessments, for dissolved winter nutrients, growing season chlorophyll and dissolved oxygen ​(Devlin and others, 2023b; Heyden and Leujak, 2022; Prins and Enserink, 2022), OSPAR and WFD/WER have used different methodologies for the indicators and for how trophic status is considered more broadly.  

WFD/WER outcomes for the period 2016 – 2021 showed that 3% of coastal waters were classified as having a status of ‘moderate’ or below for biological elements that are likely to respond to excess nutrient concentrations, thus not achieving GES (Table 3; Figure 1). A further 2.3% of coastal waters had a risk of future failures due to existing high dissolved inorganic nitrogen (DIN) concentrations. All UK OSPAR assessment areas have been classified as achieving GES based on outcomes of the common indicators. Assessment thresholds for the three common indicators were not exceeded in UK waters, including those shared with other OSPAR countries (Figure 1). However, approximately 6% (152, 900 km2) of the OSPAR Maritime Area in the North-East Atlantic has been classified as eutrophic with transboundary issues playing a part in these failures. Therefore, the OSPAR 2010 objective “to combat eutrophication, with the aim of achieving and maintaining a healthy marine environment where anthropogenic eutrophication does not occur” has not yet been fully achieved.  

Table 2: Outcomes (reported as a (A) number and (B) percentage of the overall number of waterbodies) for the UK for the eutrophication assessment for the WFD/WER waterbodies. Indicators include dissolved inorganic nitrogen (DIN), dissolved oxygen (DO), opportunistic macroalgae (Opp Mac) and phytoplankton (PP, a multi- metric of chlorophyll and plankton abundance).  ‘In GES’ means Waterbodies that have been designated (based on the common indicators) as being in Good Environmental Status. ‘Not in GES’ means Waterbodies that have been designated as not in Good Environmental Status. ‘No Data’ are waterbodies that were not assessed for eutrophication in this round of reporting. Note also that 90% of Scotland waters were carried over from the last WFD reporting. These latter points affect the overall confidence of the results. 

All WFD/WER coastal assessment areas - Number Waterbodies in each classification category
Class	DIN	DO	Opp Mac	PP
High (in GES)	431	517	458	463
Good (in GES)	56	3	31	59
Moderate (not in GES)	20		4	10
Poor (not in GES)
Bad (not in GES)	2
Not assessed (No data)	51	40	67	28
Total	560	560	560	560

All WFD/WER coastal assessment areas - Number Waterbodies in each classification category (%)
Class	DIN	DO	Opp Mac	PP
High (in GES)	77%	92%	82%	83%
Good (in GES)	10%	1%	6%	11%
Moderate (not in GES)	4%	0%	1%	2%
Poor (not in GES)	0%	0%	0%	0%
Bad (not in GES)	0%	0%	0%	0%
Not assessed (No data)	9%	7%	12%	5%
Total	100%	100%	100%	100%

Table 3: Outcomes of the overall number of waterbodies for each region for eutrophication indicators for the WFD/WER waterbodies only. Indicators include dissolved inorganic nitrogen (DIN), dissolved oxygen (DO), opportunistic macroalgae (Opp Mac) and phytoplankton (PP, a multi- metric of chlorophyll and plankton abundance). The one out all out eutrophication (OOAO Eut) value is the assessment outcome derived from the one-out-all-out approach across the indicators, with the lowest value representing the overall assessment.  Not assessed waterbodies are waterbodies with no assessment carried out in this time period. The OOAO waterbodies are also presented as surface area (km2 covered).   

Winter DIN	UK total	England	NI	Scotland	Wales
	No WBs	No WBs	No WBs	No WBs	No WBs
total waterbodies	560	61	19	457	23
Good status (at GES)	473	24	15	423	11
Not good status (not at GES)	22	12	4	0	6
No assessment	65	25	0	34	6
Phytoplankton	UK total	England	NI	Scotland	Wales
	No WBs	No WBs	No WBs	No WBs	No WBs
total waterbodies	560	61	19	457	23
Good status (at GES)	342	35	19	277	11
Not good status (not at GES)	10	7	0	0	3
No assessment	208	19	0	180	9
Opp Macroalgae	UK total	England	NI	Scotland	Wales
	No WBs	No WBs	No WBs	No WBs	No WBs
total waterbodies	560	61	19	457	23
Good status (at GES)	316	9	16	277	7
Not good status (not at GES)	4	1	3	0	0
No assessment	240	51	0	180	16
Dissolved Oxygen	UK total	England	NI	Scotland	Wales
	No WBs	No WBs	No WBs	No WBs	No WBs
total waterbodies	560	61	19	457	23
Good status (at GES)	391	44	19	328	0
Not good status (not at GES)	0	0	0	0	0
No assessment	169	17	0	129	23
OOAO Eut	UK total	England	NI	Scotland	Wales
	No WBs	No WBs	No WBs	No WBs	No WBs
total waterbodies	560	61	19	457	23
Good status (in GES)	480	30	14	426	10
Not good status (not at GES)	27	14	5	0	8
No assessment	53	17	0	31	5
OOAO Eut	UK	England	NI	Scotland	Wales
Area covered (km2)
Good status (in GES)	55947	4892	1203	47836	2017
Not good status (not at GES)	2551	1793	94	0	747
No assessment	1367	1142	0		225

Achievement of targets and indicators used to assess progress in 2024

Chlorophyll

Dissolved oxygen

Nutrient concentrations

Nutrient inputs

WFD/WER outcomes

 

Photographic credits: Chlorophyll © NEODAAS. Dissolved oxygen © Elisa Capuzzo, Cefas, Crown Copyright. Nutrient concentrations © Dave Sivyer, Cefas, Crown Copyright. Nutrient inputs © Flickr_Photo Credit Editor5807Wikimedia commons – Creative Commons L.

Drivers, activities and pressures affecting the state of the marine environment

Inputs of dissolved nitrogen and phosphorous from land-sources (diffuse via rivers including agricultural run-off; more direct via sewage, and industry outfalls), have decreased since 1990 (Figure 3). Run-off from agricultural land has been identified as the predominant source of the nitrogen discharges to the North-East Atlantic waters over the last two decades ​(Axe and others, 2023; Devlin and others, 2023a)​ . Nitrogen and phosphorus consumption in agriculture reduced from the early 1990’s as a result of improved fertilizer application and the onset of the EU Urban Waste Water Directive ​(Hukari and others, 2016)​. Assessments for the year 2010 suggest that the average reference values for critical nitrogen loads were exceeded, underscoring that fertilizer applications in agriculture continue to drive eutrophication issues ​(Fanelli, 2019)​. 

Figure 3: Three graphs are displayed. Total UK inputs of nitrogen (top left) and phosphorous (top right) to the marine environment from rivers and direct terrestrial discharges (sewage, industrial and aquaculture sources downstream of the tidal limit), as well as atmospheric deposition to the UK Exclusive Economic Zone (EEZ) as modelled for OSPAR by the European Metrological Synthesising Centre-West. Statistics of a simple linear and Mann-Kendall (M.-K.) trend analysis are shown (r-sq: r2 value) for both the full monitoring timeseries and the most recent years. Bottom: summary of Mann-Kendall trend analysis for each of the UK terrestrial input reporting units, displayed from region E1, with dashed vertical lines indicating national boundaries (E23-E27: Wales; SC-regions in Scotland; NI-regions in Northern Ireland), with regional and whole-UK aggregations on the right-hand side. Symbology follows Figure 2, with downwards blue triangles indicating decreasing trends and upwards red triangles indicating increasing trends as quantified by Mann-Kendall analysis.

 

Impact of pressure on ecosystem services

The UK’s nearshore coastal and plume waters are under the most pressure from land-based pollution and have the highest value to society in terms of recreation and visual amenity. Increased nutrient loads and changing proportions of nutrients have resulted in biomass and phytoplankton species shifts which can in turn impact higher trophic assemblages. These have significant economic impacts by reducing the appeal and amenity value of coastal waters (Stebbings and others, 2020; Elliot and others, 2018). Affected areas include shallower waters where seagrasses and seaweeds maintain nursery populations and habitat structure. More serious eutrophication involves hypoxic events which harm many organisms but are particularly damaging to sessile benthic fauna. 

Impacts of climate change on pressures and state

Under future climate change scenarios, higher annual mean river flow is expected in the Celtic Seas and Greater North Sea. Increased nutrient loading could be expected if river discharges increase but loads also depend largely on future land use and socio-economic developments ​(Arheimer and others, 2012).​ A recent Defra-funded project considered possible shifts in the seasonal timing of phytoplankton growth in response to potential climate-driven changes in nutrient inputs, i.e., shift from a Nov to Feb input peak to a Dec to March peak (Greenwood and others, 2025). Such a temporal shift would have implications for which months are considered in assessment methodology and timing of peak phytoplankton months.   

Climate change may also have an impact on the direct and indirect effects of nutrient enrichment. Increased water temperatures have been shown to lead to phenological shifts, biogeographical changes and changes in abundance of plankton (see ​Brander and others, 2016​ for an overview).   

The indirect effects of eutrophication on oxygen concentrations in the near-bottom water layer now show localised but persistent areas of oxygen deficiency in the Greater North Sea. Climate change can impact upon dissolved oxygen concentration in many ways, most evidently via the direct effect of temperature on solubility. Higher water temperatures can also increase metabolic rates and oxygen demand of marine organisms and increase stratification, which inhibits the supply of oxygenated waters to depth (Greenwood and others, 2010). The seasonal duration of stratification is expected to increase and regions that show oxygen depletion are expected to become larger ​(Wakelin and others, 2020).​   

It is also important to consider ocean acidification and its interaction with eutrophication effects. There are likely to be changes in our activities to reduce greenhouse gas emissions which could affect the scale of the eutrophication impacts. There is also the need to consider the role of eutrophication in short-term oxygen depletion and how we will separate this response from climate change impacts.

Management actions taken

The actions we are taking to achieve GES for eutrophication are set out in the UK Marine Strategy Part 3 2025: Programme of Measures.  

Starting as early as 1988, the OSPAR Contracting Parties agreed to reduce nutrient emissions to the Greater North Sea by 50%. Since then, several OSPAR Recommendations, land management initiatives and controls from regulations such as The Urban Wastewater Treatment Directive (UWWTD) (Council Directive 91/271/EEC) and Water Framework Directive (now The Water Environment (Water Framework Directive) (England and Wales) Regulation 2017) have been taken to combat eutrophication. These include measures targeting diffuse run-off from land, atmospheric nitrogen emissions, wastewater, and other point sources. These responses have led to significant improvements in nutrient loadings to the OSPAR Maritime Area since the start of monitoring in 1990. During the last decade, improvement trends have slowed down, with increasing concerns regarding increasing nutrient inputs from diffuse agricultural loads, combined sewage overflows and the growing marine aquaculture industry.  

Next steps

Evidence challenges

The causes of eutrophication are complex and compound. Our key challenges are to: 

• Ensure that Total Nitrogen (TN) and Total Phosphorus (TP) loads are measured correctly across the UK so we can effectively measure where concentrations do not exceed modelled pre-eutrophic conditions.   

• Ensure nutrient input monitoring demonstrates effectiveness of relevant measures in tackling eutrophication in coastal areas.  

• Effectively quantify changes in plankton communities and link this to eutrophication and pelagic indicators. This will help us understand how eutrophication affects food webs and wider ecosystem functioning and how eutrophication is in turn affected by climate change.  

• Integrate novel and high frequency data, such as Earth Observation satellite data, into traditional monitoring and assessments.  

Other challenges include: 

• Integrating UKMS, OSPAR and WFD/WER assessment and reporting processes for Coastal waters, including greater harmonisation of indicators and assessment boundaries. 

• Fully develop river basin management, utilising an integrated ‘Catchment to Coast’ approach to manage the input of terrestrial pressures into our marine environment. 

Operational objectives

Water quality regulations are devolved across the UK. We will continue to manage non-climate pressures through programmes of measures to reduce nutrient loading, ensuring balanced systems result in a more resilient ecosystem, benefiting both humans and the environment they depend on. 

We will work with other countries to deliver OSPAR commitments reinforced in the OSPAR Strategy for the Protection of the Marine Environment of the North-East Atlantic (NEAES) 2030.   

Other headline objectives include: 

Shared: 

• We will work with others to deliver the OSPAR Strategy for the NEAES 2030. Including investigating how we can contribute to the commitment to determining maximum nutrient inputs and agreeing nutrient reduction needs. 

• We will continue to manage non-climate pressures through programmes of measures to reduce nutrient loading. 

• Improved join-up between OSPAR and WER/WFD to ensure linkages between eutrophication and biodiversity, and between eutrophication and climate change.   

England only: 

• Work to enable delivery of core targets as set out in the Environmental Improvement Plan (EIP) and Environment Act 2021. 

Wales only: 

• Work to achieve targets under the Water Resources (Control of Agricultural Pollution) (Wales) Regulations 2021.  

Scotland only: 

• Work to enable delivery of Scotland’s River Basin Management Plan 2021-27 targets. 

Northern Ireland only: 

• Work to improve water quality in the shared waters between Northern Ireland and Ireland through enhanced wastewater treatment. 

Technical Detail: Good Environmental Status for the next cycle

Overarching target
Human-induced eutrophication in UK seas is minimised
Criteria	2024-2030 GES targets	Comment	Indicators
Nutrient concentrations	Nutrient concentrations are below the levels which could lead to harmful eutrophication effects.	No change	Nutrients
Nutrient Ratios	Nutrient ratios are below levels which could harm the plankton community.	New Criteria and Target. Required due to improvements in monitoring and to enable better alignment with ambitions under OSPAR.	Nutrients
Nitrogen and Phosphorus Loads	Total Nitrogen (TN) and Total Phosphorus (TP) Loads (where measured) do not exceed the modelled pre-eutrophic conditions with appropriate variability added to the threshold.	New Criteria and Target. Suggested as an indicator in 2019 based on OSPAR monitoring of ‘nutrient loads of Dissolved Inorganic Nitrogen and Dissolved Inorganic Phosphorus’. Due to requirements of OSPAR to monitor TN and TP annually, this is now proposed as new Criteria and Target.	Nutrients
Chlorophyll a concentrations	Chlorophyll a concentrations are below levels which could lead to harmful eutrophication effects.	No change	Phytoplankton
Dissolved Oxygen content	Dissolved oxygen content in coastal waters is above levels which could lead to harmful eutrophication effects.	No change (altered wording from ‘are’ to ‘is’ for improved syntax).	Dissolved oxygen
Measures of plankton community/change	Demonstrate an acceptable balance of plankton communities that will support ecological functioning, carbon uptake and food web dynamics.	New Criteria and Target. Will achieve better alignment with biodiversity measures and track progress against nutrient imbalances	Biodiversity and Eutrophication

The following are proposed new targets to explore for this next assessment round. These are influenced by activities occurring under OSPAR.  

• Nutrient ratios are below levels which could harm the plankton community.  

• Total Nitrogen (TN) and Total Phosphorus (TP) loads (where measured) do not exceed the modelled pre-eutrophic conditions with appropriate variability added to the threshold.    

• Measures of plankton community/change demonstrate an acceptable balance of plankton communities that will support ecological functioning, carbon uptake and food web dynamics. 

References

Anon (2022) State of the Water Environment – Eutrophication (2022) combined assessment.  https://www.gov.uk/government/publications/state-of-the-water-environment-indicator-b3-supporting-evidence/state-of-the-water-environment-indicator-b3-supporting-evidence. Webpage updated 27 January 2025 

Anon (2023) State of Scotland’s Water Environment, Summary Report 2023, Scottish Environment Protection Agency. Data found at https://informatics.sepa.org.uk/WaterClassificationHub/.  

Anon (2024a). Northern Ireland Water Classification Statistics 2024 Report | Department of Agriculture, Environment and Rural Affairs. Data downloaded from https://gis.daera-ni.gov.uk/arcgis/apps/webappviewer/index.html?id=e44a8e27333241bfa2faf4a387fd99d7 

Anon (2024b) Assessment of water quality in Wales 2024 under Water Environment(Water Framework Directive)(England and Wales) Regulations 2017 . Data found at https://waterwatchwales-nrw.hub.arcgis.com/ 

Arheimer, B., Dahné, J., and Donnelly, C. (2012). Climate change impact on riverine nutrient load and land-based remedial measures of the baltic sea action plan. Ambio, 41(6).   

​Axe, P., Sonesten, L., Skarbövik, E., Leujak, W., and Nielsen, L. (2023). Inputs of Nutrients to the OSPAR Maritime Area.In OSPAR, 2023: The 2023 Quality Status Report for the North-East Atlantic.  

​Brander, K. M., Ottersen, G., Bakker, J. P., Beaugrand, G., Herr, H., Garthe, S., Gilles, A., Kenny, A., Siebert, U., Skjoldal, H. R., and Tulp, I. (2016). Environmental Impacts—Marine Ecosystems. https://doi.org/10.1007/978-3-319-39745-0_8  

​​Devlin, M., Prins, T. C., Enserink, L., Leujak, W., Heyden, B., Axe, P., Ruiter, H., Blauw, A., Bresnan, E., and Collingridge, K. (2023a). A first ecological coherent assessment of eutrophication across the North-East Atlantic waters (2015-2020).  

Devlin, M., Fernand, L., and Collingridge, K. (2023b). Concentrations of dissolved oxygen near the seafloor in the greater North Sea, Celtic Seas and Bay of Biscay and Iberian Coast. OSPAR.  

​Elliott, L. R., White, M. P., Grellier, J., Rees, S. E., Waters, R. D., and Fleming, L. E. (2018). Recreational visits to marine and coastal environments in England: Where, what, who, why, and when? Marine Policy, 97, 305–314. https://doi.org/https://doi.org/10.1016/j.marpol.2018.03.013  

​Fanelli, R. M. (2019). The (un)sustainability of the land use practices and agricultural production in EU countries. International Journal of Environmental Studies, 76(2). https://doi.org/10.1080/00207233.2018.1560761  

​Graves, C. A., Best, M., Atkinson, A., Bear, B., Bresnan, E., Holland, M., Johns, D. G., Machairopoulou, M., McQuatters-Gollop, A., Mellor, A., Ostle, C., Paxman, K., Pitois, S., Tett, P., and Devlin, M. (2023). At what scale should we assess the health of pelagic habitats? Trade-offs between small-scale manageable pressures and the need for regional upscaling. Ecological Indicators, 154. https://doi.org/10.1016/j.ecolind.2023.110571  

​Heyden, B., and Leujak, W. (2022). Winter Nutrient Concentrations in the Greater North Sea, Celtic Seas and Bay of Biscay and Iberian Coast. In: OSPAR, 2023: The 2023 Quality Status Report for the Northeast Atlantic. OSPAR Commission, London.  

​Hukari, S., Hermann, L., and Nättorp, A. (2016). From wastewater to fertilisers—Technical overview and critical review of European legislation governing phosphorus recycling. Science of the Total Environment, 542, 1127–1135.  

​ICES (2022). Input data files for the OSPAR COMP 4 eutrophication assessment using COMPEAT. Data Outputs. Dataset. https://doi.org/10.17895/ices.data.22189111.v1 

Prins, T., and Enserink, L. (2022). Concentrations of Chlorophyll-a in the Greater North Sea, Celtic Seas and Bay of Biscay and Iberian Coast. In: OSPAR, 2023: The 2023 Quality Status Report for the Northeast Atlantic. OSPAR Commission, London.  

​Stebbings, E., Papathanasopoulou, E., Hooper, T., Austen, M. C., and Yan, X. (2020). The marine economy of the United Kingdom. Marine Policy, 116, 103905. https://doi.org/https://doi.org/10.1016/j.marpol.2020.103905  

​Wakelin, S. L., Artioli, Y., Holt, J. T., Butenschön, M., and Blackford, J. (2020). Controls on near-bed oxygen concentration on the Northwest European Continental Shelf under a potential future climate scenario. Progress in Oceanography, 187. https://doi.org/10.1016/j.pocean.2020.102400  

Contributors

Michelle Devlin, Carolyn Graves, Naomi Greenwood, Robert Brooks, Mike Best, Fiona Napier, Trevor Harrison, Mark Charlesworth.