### National Report on the Eutrophicati on Status of UK waters

April 2008 

## 1 

# Common Procedure for the Identification of the Eutrophication Status of the OSPAR Maritime Area

UK National Report

### National Report on the Eutrophicati on Status of UK waters

April 2008 

## 2 

# Table of contents

Table of co ntents ___________________________________________________________ 2

1 Introduction __________________________________________________________ 4

2 Description of a ssessed a reas _____________________________________________ 6

3 Methods and data ______________________________________________________ 9

3.1 Criteria for the OSPAR Comprehen sive Procedure assessment ___________ 9

3.2 Inventory of ava ilable data_________________________________________ 15

4 Eutrophication assessmen t ______________________________________________ 18

4.1 Outline of assess ment pr ocess ______________________________________ 18

4.2 Assessment under the EC Urban Wa ste Water Treatment Directive

(UWWTD) and Nitrat es Directive (ND)_____________________________________ 18

4.3 Assessment of Transboundary Transport of Nutrients _________________ 20

5 Comparisons with European eutr ophication related policies ___________________ 48

6 Perspecti ves __________________________________________________________ 49

6.1 Measures taken to address UK Proble m Areas and Potential Problem Areas __ 49

6.1.1 Problem Areas and potential Problem Areas designated in 2002 _________________49

6.1.2 Measures taken to reduce the inputs of Nutrients from UK Problem Areas and Potential

problem areas________________________________________________________________50



## 6.2 Outlook_________________________________________________________ 52

6.2.1 Expected trends _______________________________________________________52

6.2.2 Improvement of assessmen ts _____________________________________________55



## 7 Conclusions on the Eutrophica tion Status of UK Seas________________________ 57

8 References ___________________________________________________________ 62

9 Annexes _____________________________________________________________ 63

9.1 Screening Re view ________________________________________________ 63

9.2 Thresholds used in the OSPAR comprehensive procedure_______________ 65

### National Report on the Eutrophicati on Status of UK waters

April 2008 

## 3 

# Table of figures and tables

Figure 1: Areas submitted to the 2008 Screening Review ........................................................................6

Figure 2: Outcome of the 2008 Screening Review ; areas with nutrient concentrations at background

levels were designated as Non-Problem (green) and assessed no further. Remaining areas (blue)

were submitted to full assessment under the Comprehensive Procedure (CP).................................7

Figure 3: Cefas SmartBuoy locations in the southern North Sea (Gabbard and Warp) and Liverpool

Bay ............................................................................................................................ .....................15

Figure 4: Sampling sites; sites were ma tched to OSPAR areas for assessments. ...................................16

Figure 5: Final classificati on for UK assessment areas. ........................................................................ .60

Figure 6: Map extracts of assessment areas in (a) Scotland, (b) Northern Ireland, and (c) English south

coast.......................................................................................................................... ......................61

Table 1: Assessment parameters and description of thresholds for the 2008 OSPAR Comprehensive

procedure...................................................................................................................... ..................11

Table 2: Evaluation of Risk of Nutrient Enriched Waters scoring “ + - -“ to Problems Elsewhere 21

Table 3: UK results of the OSPAR Comp rehensive Procedure Assessment 2008. ................................23

Table 4: UK Problem Areas and Potential Problem Areas reported to OSPAR in first application of the

Comprehensive Procedure in 2002; sensitive areas (SA) under the UWWT Directive and nitrate

vulnerable zones (NVZ) under the Nitrates Directive ....................................................................49

Table 5: Expected Eutrophication Status of UK waters examined under the OSPAR Comprehensive Procedure 5 4

Table 6 Final classifi cation of UK areas....................................................................................... ..........59

Table 7: Summary results of the 2008 screening procedure for England and Wales. Data were

separated into spa tial and te mporal............................................................................................ .....63

Table 8: Summary of phytoplankton indices (IE) relating to the occurrences of elevated taxa counts

within a whol e popula tion ...................................................................................................... ........65

Table 9: Thresholds for assessment of macroalgae blooms under the OSPAR CP ................................65

Table 10: Proposed dissolved oxygen standards for naturally ventilated layers (or rapidly exchanged

stratified waters) of transitio nal and coasta l waters........................................................................66

Table 11: Assessment criteria for Category IV – occu rrence of toxicity in bivalve mollusc tissue and

presence of toxin producing algae. ............................................................................................. ....67

### National Report on the Eutrophicati on Status of UK waters

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## 4 

# 1 Introduction

This report presents the outcome of the second application of the Comprehensive Procedure

assessment to OSPAR maritime waters in th e jurisdiction of the United Kingdom. The

purpose was to assess the status of waters, on the basis of a harmonised set of assessment

criteria to provide an initial classification and, using further supporting evidence, to produce a

final classification, as either Non Problem Area or Problem Area with respect to

eutrophication. Where there was uncertainty a further assessment category of Potential

Problem Area has been assigned.

The first application of the Common Proce dure in 2002 applied the agreed Screening

Procedure to define obvious Non Problem Are as and focused attention and resources on those

areas to which the Comprehensive Procedure was sub sequently applied. In line with the spirit

of the agreement (but not formal requi rement) the UK carried out a further screening review

in the light of known changes and our developi ng understanding of overall ecological status to

conclude on the areas to which the Compre hensive Procedure would be applied.

A thorough review was undertaken of the thr esholds applied for each of the Harmonised

Assessment Criteria, taking account of regional differences where this was required, lessons

learned from the first application and national developments in the field of eutrophication

assessment, including work with respect to Euro pean Directives. Where it is scientifically

justified, we have used similar thresholds acr oss the wide variety of water types in the UK

area for simplicity and transparency.

The UK assessment follows the Comprehensiv e Procedure Guidance as closely as possible

but in the light of the characteristics of UK waters, we have deployed methods that are

considered to be more rigorous and improve th e quality of the assessment. This is made clear

in the report.

It is important to ensure that the methodology has been applied well and that the conclusions

are based on robust and reliable evidence. To ensure that this is the case the area based

assessments have been subject to an open peer review process. Three international experts,

led by Prof Paul Tett (Napier University), we re commissioned to undertake the review, which

concluded with a public workshop challenging all aspects of the work. The key findings of

the review have been incorporated into this report either as changes to overall classification

where this was based on evidence or changes affecting the robustness and level of confidence

in the classification. The evaluators suggest ed some improvements to the Comprehensive

### National Report on the Eutrophicati on Status of UK waters

April 2008 

## 5 Procedure assessment approach which will be submitted separately to OSPAR for

consideration (the issues are summarised later in this report) and also proposed changes

towards greater consistency of approach across the UK which will be taken up by the national

authorities. Findings from the evaluators report will be submitted to OSPAR EUC, for

information.

We have not included a specific chapter on the implementation of the integrated set of

EcoQOs for eutrophication. The UK believes that the overall assessment provided by the

application of Comprehensive Procedure provid es the relevant information with respect to

ecosystem health and is the most appropriate assessment to target the development of any

measures which might be needed.

The first application of the Comprehensive Proce dure resulted in identification of most of the

UK maritime area as Non Problem Area status with 12 estuaries/embayments identified as

Problem Areas and 4 estuaries/embayments as Potential Problem Areas. There were 5 Non

Problem Areas downstream of catchments with a size of population and/or level of

agricultural activity that were of continuing in terest and required monitoring to assure their

continuing NPA status. These areas are highlight ed in the assessment (Table ). The overall

UK eutrophication monitoring programme was modi fied providing additional surveillance in

particular areas of concern.

The results of this second application of th e Comprehensive Procedure, which broadly

confirm those of the first application, can be found in Chapter 7 and in summary form in

Table 6, on page59.

The detailed results within the maritime juri sdiction of the UK are presented in a series of

separate area reports, which are availabl e electronically from the following link:

www.cefas.co.uk/ospardocs.

### National Report on the Eutrophicati on Status of UK waters

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## 6 

# 2 Description of assessed areas

Figure 1: Areas submitted to the

2008 Screening Review

A screening review was undertaken to provide assurance that areas previously identified as

obvious Non Problem Areas (NPA) through application of the Screening Procedure in 2002

were still NPAs; taking account of any known ch anges in pressures and through a simple

evaluation based on a comprehensive, qua lity assured database of winter nutrient

concentrations (Section 9.1, Annexes). Th e areas submitted to the screening review are

shown in Figure 1. The review confirmed the previous assessment and further identified that

waters in the North Sea to the east of Scotland could also be excluded from the

Comprehensive Procedure Assessment due to nutrient concentrations being near background

and no identified risks of significance.

The areas identified for assessment included speci fic estuaries and embayments (transitional

waters – TW), areas of coastal water with si gnificant freshwater input and offshore areas,

either well mixed or seasonally stratified. Sub-division of these wider sea areas is on the

basis of a good understanding of ecological type . Boundaries are also set on the basis of

national jurisdiction e.g. the median line in the North Sea and Channel. The UK assessment

areas are shown in Figure 2.

### National Report on the Eutrophicati on Status of UK waters

April 2008 

## 7 Figure 2: Outcome of the 2008 Screening Review ; areas with nutrient concentrations at

background levels were designated as Non- Problem (green) and assessed no further.

Remaining areas (blue) were submitted to full assessment under the Comprehensive

Procedure (CP).

### National Report on the Eutrophicati on Status of UK waters

April 2008 

## 8 Where we have identified some large sea ar eas for assessment and to ensure that any

problems are not overlooked (reflecting that many such problems are closely associated with

nutrient enriched freshwater inputs), we have ca rried out the assessment of waters within each

area on the basis of salinity gradients, whic h result from the mixing of freshwater and

seawater. These are presented in terms of thr ee salinity regimes, but each assessment area

will have a dominant salinity regime that is the basis for overall assessment. The salinity

regimes are:

• Estuarine: All areas – salinity range 0 – <30.0

• Coastal: Irish Sea – salinity range 30 – 34.0

North Sea – salinity range 30 – 34.5

• Offshore: Irish Sea – salinity range > 34.0

North Sea – salinity range >34.5

Some of the UK estuaries/embayments have al so received prior assessment of eutrophication

status for the purposes of the EC Urban Waste Water Treatment (UWWT) Directive and

Nitrates Directive (ND). Wher e these assessments have resulte d in designation as a Sensitive

Area (eutrophic) or Polluted Water (eutrophic) then they are deemed, subject to confirmation,

to be either OSPAR Problem Areas or OSPAR Potential Problem Areas.

### National Report on the Eutrophicati on Status of UK waters

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## 9 

# 3 Methods and data

The UK assessment follows the Comprehensive Procedure Guidance as closely as possible,

but in the light of the characteristics of UK waters and national development of methods that

will be used for the Water Framework Directiv e classification, we have deployed methods

that are now considered to be more rigorous and improve the quality of the assessment. The

developments are for chlorophyll, phytoplankton indicators, macrophytes (including

macroalgae) and oxyge n (see Section 4.1).

3.1 Criteria for the OSPAR Comprehensive Procedure assessment

The UK application of the assessment criteria and a detailed description of the assessment

parameters for the categories is summarised in Table 1 (page 11).

Category I: Degree of Nutrient Enrichment

. Each of the Harmonised Assessment Criteria

for Category I has been applied according to the CP Guidance. Riverine Input and Direct

Discharge (RID) information is utilised for areas that are adjacent to the coast. Nutrient

concentration information focuses on winter dissolved inorganic nitrogen (DIN = NO 2 

## + NO 3



## + NH 4 

## ) as the primary criterion and is used in each assessment area/salinity regime,

normalised to the relevant salinity. We have not used winter dissolved inorganic phosphorus

as a primary criterion, unless assessment of the winter DIN/DIP (DIP = dissolved inorganic

phosphorous) ratio suggests phosphorus limita tion. We have not found such cases.

Category II: Direct Effects of Nutrient Enrichment . Harmonised Assessment Criteria

have been subject to detailed national scrutin y (also in association with work-streams to

implement the Water Framework Directive) and the following specific approaches for this CP

Assessment have been developed. Chlorophyll is assessed using the 90 th 

## percentile for the

March to September growing season, which will inevitably include high spring-bloom

chlorophyll values and this is why the 90 th 

## percentile (rather than the 95 th 

## percentile, for

example) was set. We have also reported the mean and maximum levels for comparison. We

do not think it sensible to assess against maximum levels, as they are difficult to sample, even

where we have deployed continuous observing equipment. Instead of a set of individual

‘phytoplankton indicator species’ we have deployed an index, which includes measures of

Phaeocystis spp. and any phytoplankton taxa with a bundance over a defined threshold. This

is to provide a better assessment of disturbance of the phytoplankton as a result of nutrient

enrichment. Areas where macrophytes are si gnificant have been assessed using a specific

index including the area covered and biomass of opportunistic macroalgal taxa. This national

### National Report on the Eutrophicati on Status of UK waters

April 2008 

## 10 development is being considered for adoption by the Intercalibration Process for the Water

Framework Directive.

The peer reviewers and our scientists have con cerns that the mix of parameters and their

formulation in Category II, confuse two aspects of the assessment of eutrophication status and

can lead to an incorrect classi fication in the initial assessment. Th is issue is considered below

(section 6.2.2)

Category III Harmonised Assessment Criteria follow such guidance as exists. We have

compared dissolved oxygen concentrations agai nst established thresholds and made best use

of any evidence of fish kills and the available widely distributed data on changes to benthic

invertebrates. We have not used informati on about organic carbon/organic matter – there are

few depositional areas in UK waters where this would be relevant, thoug h it may be relevant

in some restricted circulation areas such as small estuaries and lochs, but is not a parameter

routinely included in our monitoring programmes.

Category IV Harmonised Assessment Criterion has been supplemented (in coastal and

estuarine regions) with information about th e frequency of toxin producing algae (TPA) in

water samples, assessed against thresholds establis hed for food safety. These data have been

collated as of interest but due to the lack of a clear scientific case linking nutrient enrichment

with either the presence or proliferation of TPA, or their presence in bivalve mollusc tissue,

we have given these parameters no weighting in our assessment. There is evidence from the

Atlantic coasts of the UK that the presence and proliferation of TPA and/or incidence of

toxicity in bivalve mollusc tissue result from fact ors other than nutrient enrichment. This will

be the subject of further investigation.

Harmonisation: In developing the approaches and thr esholds to be applied on a regional

basis the UK has, as far as possible, harmonized with UK national programmes set up to

implement the Water Framework Directive which follow the recommendations for assessment

levels agreed by the North East Atlantic Geographical Inter-calibration Group. The UK has

also noted that some Contracting Parties borderi ng the North and Irish seas use thresholds, of

a similar order for nitrogen and chlorophyll, giving confidence that assessments of similar

offshore and coastal waters are being carried out on a comparable basis.National Report on the Eutrophication Status of UK watersApril 200811Table 1: Assessment parameters anddescription of thresholds for the 2008OSPAR Comprehensive procedure.Assessment Parameters DescriptionCategory I. Degree of nutrient enrichment (causative factors);1. Riverine inputs and directdischarges (area specific)Annual inputs for each year assessed (displayed as bar chart) for direct receiving area. Analyse for trend overlongest time series available.An increasing trend scores +.2. Nutrient concentrations(area specific)Elevated level(s) of winterDIN and/or DIPThe winter period defined as November – February inclusive. Thresholds for nutrients based on referencefreshwater end point (42 μM, S = 0) and marine reference concentration (10 μM, S = 35). Thresholds can benormalised to any specific salinity.For example, North SeaWinter DIN thresholds – relative to salinity/area1.Estuary – normalised to salinity of 25. Ref value = 20μM; + 50% = threshold of30μMCoastal – normalised to salinity 32. Ref value = 13μM; + 50 % = threshold of20μMOffshore2– normalised to salinity 34.5 Ref value = 10μM; + 50 % = threshold of15μMP is assessed as part of the N/P ratio (see assessment parameter 3, below). Winter DIP alone will not be presentedunless P limitation indicated because of its complex behaviour in estuaries and areas with fine sediment.Notes1Threshold values are presented for two nominal ranges ofsalinity. Assessments can be based on any point alongthe reference dilution line2For Irish Sea – more appropriate to use >34 for offshore waters3. N/P ratio (area specific)Elevated winter N/P ratio(Redfield N/P = 16)Significant deviation (>50%) from Redfield ratio basedon annual winter average nutrient concentrations1N:P 24:1(Additional information may be supplied for N:Si 2:1)Notes1Ratios are calculated for each sample and averaged over the assessment area. (SE can be associated with the ratio).Category II. Direct effects of nutrient enrichment;National Report on the Eutrophication Status of UK watersApril 200812Assessment Parameters Description1. Chlorophyllconcentration (areaspecific)•Elevated percentile,90thpercentile for period March – September (reflects WFD European Intercalibration approach).ThresholdsEstuarine –15μg l-1Coastal –15μg l-1Offshore –10μg l-1Mean and maximum concentrations are also reported as supporting evidence.2. Phytoplankton indicators(area specific)•Elevated levels ofphytoplanktonspecies (andincreased duration ofblooms)Phytoplankton assessment using new phytoplankton index approach based on:Total cell count – assessment of occurrences over 107Phaeocystiscell count – occurrences over 106Any single taxa – occurrences over 106Chlorophyll concentrations – occurrences exceeding 10μg l-1Threshold set on allexceedance counts being less than 25% of all sampling times over 5 years.Description of indexThis index is designed to assess if the presence, abundance and frequency of occurrence of elevated counts of algalspecies correspond to undisturbed conditions. The tool is composed of four attributes, one which is a measure of thefrequency that elevated biomass [chl] exceeds a referencethreshold and three of which focus on counts of algaethat may result in the decline of ecosystem health or result in an undesirable disturbance. The classification toolworks by recording the number of events, defined by sampling occasions when the sum of the four attributesexceeds these predefined thresholds over the period of the monitoring programme. Each attribute is calculatedfrom the number of times that the sub-metric exceeds the threshold as a proportion of the total number of samplingtimes and calculated as a six year mean. Final classification score is based on the mean of all four attributes (as a%).The UK believes that this index, which is being developed for Water Framework Directive classification, gives abetter assessment of phytoplankton species than just looking at individual species.National Report on the Eutrophication Status of UK watersApril 200813Assessment Parameters DescriptionThe index is described in detail in:Marine Pollution Bulletin 55 (2007) 91–1033. Macrophytes includingmacroalgae (are specific)Shift from long-lived to short-lived opportunistic species (e.g.Ulva)Thresholds recommended for macroalgal biomass and area coverage based on those developed under the WFD.Category III. Indirect effects of nutrient enrichment (during growing season);1.Oxygen deficiency•Decreased levels (< 4mg l-1) and lowered% oxygen saturationThe assessment levels that are usedare concentrations measured below4 mg l-1to judge whether oxygen is scoredas an undesired oxygen deficiency level for each area•Assessment will be for period of summer/autumn (May – September)•5%ile thresholds.National Report on the Eutrophication Status of UK watersApril 2008142. Zoobenthos and fish•Kills (in relation tooxygen deficiencyand/or toxic algae)•Long term areaspecific changes inzoobenthos biomassand speciescompositionIncidence of fish kills or documented changes in zoobenthos will be presented to assess level of disturbance relatedto eutrophication.3. Organic Carbon/OrganicMatterNot applied in UK waters unless sedimentation area identified and data available.Category IV. Other possible effects of nutrient enrichment.1. Incidence of DSP/PSPmussel infection eventsIncidence of toxicity in bivalve mollusc tissue e.g. DSPor PSP mussel infection events. Frequency of occurrencesin excess of FSA limits.Additional assessment based on analysis of Toxin ProducingAlgae (TPA) in water samples. Frequency of TPAoccurrence should be below the FSA limits.

### National Report on the Eutrophicati on Status of UK waters

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## 15 3.2 Inventory of available data

Data used in this assessment are provided by the UK National Marine Monitoring Programme

(NMMP), which implements the OSPAR Co -ordinated Environmental Monitoring

Programme for Eutrophication, together with data collected for other assessments of

eutrophication status. The majority of UK marine waters were classified under the 2002

application of the Comprehensive Procedure as Non-Problem Areas which limits the NMMP

data collection to winter nutrient concentrati ons. However, the 2002 application of the CP

identified areas of particular continuing inter est that required ongoing monitoring, including

the East England, East Anglia, Liverpool Bay, Solent and the Clyde , and these have been

sampled for all relevant harmonised assessment criteria, and in several cases have undergone

intense surveillance using in-situ sampling equipment (SmartBuoys) or specifically

commissioned surveys by the Environment Agency . The Cefas SmartBuoy sites are shown in

Figure 3.

Figure 3: Cefas SmartBuoy locations in th e southern North Sea (Gabbard and Warp)

and Liverpool Bay

Further monitoring and research have been carried out in support of Eu ropean Directives and

through national/internatio nal research programmes to provide a rich and well distributed set

of relevant data (Figure 4)

### National Report on the Eutrophicati on Status of UK waters

April 2008 

## 16 Figure 4: Sampling sites; sites were ma tched to OSPAR areas for assessments.

Time Period for Data Collection

Monitoring information for the period 2001 – 2005 has been used for most of the areas

assessed. There are some areas where, for some pa rameters, adequate (in quantity or quality)

data were not available and this has caused us to assign a lower confidence to the parameter

### National Report on the Eutrophicati on Status of UK waters

April 2008 

## 17 assessment. Time series information exists for several parameters extending well beyond the

assessment period. These data have been included in assessment of trends.

Adequacy of the Data and Confidence in the Assessment

The data sets are generally ‘fit for purpose’ provi ding adequate spatial coverage and temporal

resolution to carry out a good assessment. Howeve r, there are variations in data coverage

between areas, reflecting the level of perceived risk and the practicalities of monitoring, and

between the different parameters where, for exam ple, there are more data available for winter

nutrient concentrations and chlorophyll than for phytoplankton species. The adequacy of the

data is reflected in the confidence with whic h we are able to reach conclusions about the

status of each area. Included in the classification table (Table , page23) is an assessment of

our confidence for each of the three aspects of eutrophication classification – nutrient

enrichment, accelerated growth and undesirabl e disturbance – and our overall confidence in

the area classification.

We have made best use of all available data th at meet strict quality assurance criteria to carry

out the area-based assessments. The data sets are summarised in Appendix I and are itemised

in detail in each area assessment report.

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## 18 

# 4 Eutrophication assessment

4.1 Outline of assessment process

The assessment process follows the 3 steps of the Comprehensive Procedure Guidance.

Step 1 is to select and apply relevant paramete rs from the table of Harmonised Assessment

Criteria to the area being assessed. This requir es the collation of appropriate data sets for the

area and the application, as required, of the releva nt statistical treatment to produce a score to

show whether or not the criterion has been exceeded (designated by a + or – for each

criterion). The respective thresholds for the pa rameters in UK waters have been highlighted

in Table 1 Step 2 uses a common format, based on the four categories of assessment criteria,

to arrive at an initial classification for the area. Examples of how the combination of scores

produces the initial classification are given in the Common Procedure guidance (OSPAR

2005-3, Section 5, Table 2).

Step 3 is an appraisal of all relevant info rmation (concerning the harmonised assessment

criteria, their respective assessment levels and the supporting environmental factors) to

provide a sufficiently sound and transparent acc ount of the reasons for assigning a particular

status to an area. This leads to the fi nal classification of the status of the area.

The results of the application of the Comprehe nsive Procedure to areas within the maritime

jurisdiction of the UK are presented in a series of separate area reports, which provide the

detailed evidence on which the overall classifica tion is based. These reports are available

electronically from the following link: www.cefas.co.uk/ospardocs. Table provides a

summary of the outcome of these assessments in the overall classification format described in

Annex 5 of the Common Procedure Guidance (OSPAR 2005-3).

4.2 Assessment under the EC Urban Waste Water Treatment Directive (UWWTD)

and Nitrates Directive (ND)

Relevant UK estuaries and coastal waters ha ve received prior assessment of eutrophication

status for the purposes of the UWWTD and ND. Most estuaries have been assessed and

where there is a weight of evidence showi ng an undesirable disturbance resulting from

nutrient enrichment, designation as Sensitive Wate rs (eutrophic) and/or identification of

Polluted Waters (eutrophic) has occurred. These designations are deemed to be either

Problem Areas or Potential Problem Areas with respect to eutrophication for the purposes of

the Comprehensive Procedure Assessment but have not, for England and Wales, been

separately assessed using the OSPAR methodology . To check the comparability of the

### National Report on the Eutrophicati on Status of UK waters

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## 19 different assessments, the OSPAR Comprehens ive Procedure has been applied to areas

designated as Sensitive Water (eutrophic) and Polluted Waters (eutr ophic) in Scotland and

Northern Ireland. The methods are found to be broadly comparable resulting in equivalent

classification of eutrophication status.

For Northern Ireland we have relied on existi ng robust assessments to come to a conclusion

about status which has already driven manage ment action in several cases. The assessment

for some Northern Ireland areas has been update d but, as noted by the peer evaluators, there

remains a mis-match with regard to the period for which data is reported and the assessment

period for the application of the Comprehensive Procedure.

### National Report on the Eutrophicati on Status of UK waters

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## 20 4.3 Assessment of Transboundary Transport of Nutrients

The OSPAR Comprehensive Procedure points ou t Contracting Parties should take into

account the risk that nutrient inputs may be tran sferred to adjacent areas where they can cause

detrimental environmental effects and Contr acting Parties should recognise that they may

contribute significantly to problem areas a nd potential problem areas with regard to

eutrophication outside their national jurisdicti on. The UK has made the following assessment

of this risk and of the associated footnotes in Table 2 of the Comprehensive Procedure.

Footnote 9 in table 2, which refers to those ar eas with nutrient enrichment but no other effects

(i.e scoring +--) states that: “The increased degree of nutrient enrichment in these areas may

contribute to eutrophication problems elsewhere”

Areas in the UK with this “+--“ score are: the No rth East Irish Sea, Liverpool Bay, the Bristol

Channel, the Solent, the Eastern English Channe l, the Clyde Estuary, the Tay Estuary, the

Eden Estuary and Carlingford Lough.

The UK has looked at these assessment areas and, on the basis of current knowledge, does not

believe that the transport of nutrients (n itrogen and phosphorus) from these areas will give

rise to undesirable disturbance in the waters of other Contracting Parties.

This evaluation is based on

3⁄4 Knowledge of general circulation and flows from the areas concerned
3⁄4 Transport from coastal to offshore waters within the UK maritime area
3⁄4 The scores for nutrient enrichment in the waters of other Contracting Parties given in
their national asessments
3⁄4 Reflection on the strength of assessment based on specific assessment parameters employed by other Contracting Parties e.g. Phytoplankton Indicator Species
3⁄4 Current information from modelling activities

The main findings of the evaluation are summarised in Table 2 below. More information is

available in the UK area reports. Futhermore the UK is leading the OSPAR modelling work

on transboundary transport which should give furt her information on this issue, particularly

for North Sea areas in the next couple of years. When this modelling exercise is completed,

the UK will see if this risk evaluation needs to be revised.

### National Report on the Eutrophicati on Status of UK waters

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## 21 Table 2. Evaluation of Risk of Nutrient Enriched Waters scoring “ + - -“ to Eutrophication Problems Elsewhere

Areas with (+ - -) initial

scores Adjacent

area Adjacent

area status Possible recipient

areas further

away Remote

Area

status Supporting

Information Evaluation of

risk of

contribution to eutrophication problems

elsewhere
Bristol
Channel Celtic Sea (UK) Non
Problem

Area (screened) Irish Sea (UK and Ireland) Non
Problem

Area (screened) Ireland has no
Problem Areas in possible recipient
waters. Ireland has
confirmed it does
not see UK nutrients
as a risk to eutrophication

status. Minimal

Liverpool Bay North East
Irish Sea Non
Problem

Area Irish Sea (UK and Ireland) Non
Problem

Area (screened) Ireland has no
Problem Areas in possible recipient
waters. Ireland has
confirmed it does
not see UK nutrients
as a risk to eutrophication

status. Minimal

NE Irish Sea Irish Sea Non
Problem

Area (screened) Irish Sea (Ireland) Non
Problem

Area (screened) Ireland has no
Problem Areas in possible recipient
waters. Ireland has
confirmed it does
not see UK nutrients
as a risk to eutrophication

status. Minimal

Carlingford Lough Northern
Ireland
and
Ireland
Coastal

Waters Non
Problem

Area (screened) Irish Sea (UK and Ireland) Non
Problem

Area (screened) Ireland has no
Problem Areas in possible recipient
waters. Ireland has
confirmed it does
not see UK nutrients
as a risk to eutrophication

status. Minimal

Solent
Coastal

Water East English
Channel
Coastal

Water Non
Problem Area (+ - - ) Southern
North Sea
offshore

UK

Belgium

Netherlands Non
Problem Area (- - -)
Potential
Problem Area (- - -)
Problem Area (- + +) Minimal

East English
Channel
Coastal

Water East English
Channel
Offshore

Water Non
Problem Area (- - - ) Southern
North Sea
offshore

UK

Belgium Non
Problem Area (- - -)
Potential
Problem Area (- - -)
Problem No positive scores
for nutrient enrichment, lack of
harmonisation of chlorophyll thresholds, weak
evidence of
undesirable
disturbance in possible recipient
PPAs and PAs. 1

1 

## Some countries have still not finalised their assessment thresholds (as at February 2008)

### National Report on the Eutrophicati on Status of UK waters

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## 22 Areas with (+ - -) initial

scores Adjacent

area Adjacent

area status Possible recipient

areas further

away Remote

Area

status Supporting

Information Evaluation of

risk of

contribution to eutrophication problems

elsewhere Netherlands Area (-+ +)

Minimal

Clyde Estuary Outer
Firth of Clyde Non
Problem Area (- - -) West of
Scotland
Costal

Waters Non
Problem

Area (screened) Transport of
nutrients in significant amounts
to waters of other
OSPAR countries unlikely Minimal

Tay Estuary East of
Scotland
Coastal

Waters Non
Problem

Area (screened) North Sea
offshore (UK, Denmark, Norway) Non
Problem

Area Minimal

Eden Estuary East of
Scotland
Coastal

Waters Non
Problem

Area (screened) North Sea
offshore (UK, Denmark, Norway) Non
Problem

Area There is no evidence
of enhanced nutrients in adjacent
coastal waters so impacts on the
waters of other
OSPAR countries is unlikely 2



### . Minimal



## Footnote 8 in table 2 of the Comprehensive Procedure , which refers to those areas classified as

problem areas scoring “-++”, “-+-“ or “--+” whic h may be caused by transboundary transport of

(toxic) algae and/or organic matte r arising from adjacent/remote areas. The UK does not have any

assessment areas which have these scores, and therefor e concludes that transboundary transport of this

nature is not responsible for eutrophication problems in UK waters.

2 

## A study of the relative importance of riverine nutrient inputs to the Scottish North Sea Coastal Zone.

Marine Pollution Bulletin

, Volume 26, Issue 11

, November 1993

, Pages 620-628National Report on the Eutrophication Status of UK watersApril 200823Table 3: UK results of the OSPAR Comprehensive Procedure Assessment 2008.Key to the tableNI Nutrient inputs (riverine and direct discharges total Nand total P)DI Dissolved nutrients (Winter DIN and/or DIPconcentrations)NP Increased winter N/P ratioCa Maximum and mean Chlorophyll a concentrationPs Region/area specific phytoplankton indicator speciesMp Macrophytes including macroalgaeO2Degree of oxygen deficiencyCk Changes/kills in zoobenthos and fish killsOc Organic carbon/organic matterAt Algal toxins (DSP/PSP mussel infection events)+ = Increased trends, elevated levels, shifts or changes inthe respective assessment parameters- = Neither increased trends nor elevated levels nor shiftsnor changes in the respective assessment parameters? = Not enough data to perform an assessment or the dataavailable is not fit for the purposeNational Report on the Eutrophication Status of UK watersApril 200824AreaCategory IDegree of nutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassificanAppraisal of all relevant information (concerning the harmonisedassessment criteria their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI Ca - O2- AtDI - Ps Ck -NorthernNorth SeaNP - Mp OcNPA•There is strong evidence that the area is notnutrient enriched (highconfidence). Although this is based on limited monitoring data theconclusion is confirmed by taking account of > 30 years of ICESdata and a published climatology report (UKCIP02, 2002).•There is evidence that there isno accelerated growth (mediumconfidence). The chlorophyll 90th percentiles were <10 μg l-1in allyears and the modified green test isalso passed. The conclusion isconfirmed by taking account of ICES data and the climatologyreport.•The available evidence does notsuggest that there is anyundesirable disturbance (low confidence).The final classification of thearea is a Non Problem Area (highconfidence), based on the lack of nutrient enrichment, the absence ofaccelerated growth and evidence that there is no undesirabledisturbance to the biology or water quality.NPANutrients(1999-2006)Biomass(1999-2004)National Report on the Eutrophication Status of UK watersApril 200825AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassificanAppraisal of all relevant information (concerning the harmonisedassessment criteria their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI Ca - O2- AtDI - Ps Ck -Southern North SeaNP - Mp OcNPA•There is no nutrient enrichment (high confidence) based uponextensive measurements from SmartBuoy time-series and spatialdata.•There is evidence of no accelerated growth (medium confidence).High intensity sampling has shown that since 2002 chlorophyll90th percentiles in waters of >34.5 salinity were below thethreshold.•The evidence available suggeststhat there is no undesirabledisturbance (medium confidence).Measurements show DO wasconsistently > 4 mg l-1, there was no detectable disturbance in thezoobenthos community and there was an absence of fish kills.The final classification of the Southern North Sea is as a Non-ProblemArea (high confidence). The resultsshow that there was no nutrientenrichment, accelerated growthor undesirable disturbanceNPANutrients(1999-2006)Biomass(1999-2006)National Report on the Eutrophication Status of UK watersApril 200826AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassificanAppraisal of all relevant information (concerning the harmonisedassessment criteria their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca + O2- At -DI + Ps - Ck -Eastern EnglishCoast (area ofparticularcontinuing interest)NP + Mp - OcPAFollowing the 2002 application of the Comprehensive Procedure thisarea was subject to enhanced monitoring and surveillance.•There is nutrient enrichment (high confidence) with winter DINexceeding the threshold.•There is evidence of acceleratedgrowth (low confidence). Thechlorophyll 90thpercentiles exceeded the threshold in the 3 yearswith sufficient data. However, the means were below thethreshold in all years, except 2004.•There is evidence of no undesirable disturbance (high confidence).The phytoplankton indicator was below the threshold and therewas no excessive opportunistic macroalgae growth. DO wasconsistently > 4 mg l-1. The zoobenthos showed no evidence forchange, there were no reported fish kills and no toxicity in bivalvemollusc tissue.The final classification of thearea is a Non Problem Area (highconfidence) based on evidence that in spite of nutrient enrichment andaccelerated growth, there high confidence that there is no evidence ofundesirable disturbance, and that PA status is not justified..NPANutrients(1999-2006)Biomass(1999-2004)National Report on the Eutrophication Status of UK watersApril 200827AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassificanAppraisal of all relevant information (concerning the harmonisedassessment criteria their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca + O2- At -DI + Ps - Ck -East Anglia (area ofparticularcontinuing interest)NP + Mp - OcPAFollowing the 2002 application of the Comprehensive Procedure thisarea was subject to enhanced monitoring and surveillance.•The area is nutrient enriched (high confidence) with winter DINexceeding the threshold in most years.•The area is assessed as showingsigns of accelerated growth(medium confidence).Chlorophyll 90thpercentiles exceeded thethreshold in 30 – 34.5 salinity, but were below threshold in salinity>34.5.•The area exhibits strong evidence of no undesirable disturbance(high confidence). The phytoplankton indicator and opportunisticmacroalgal growth levels were below their thresholds. DO wasconsistently > 4 mg l-1. The zoobenthos showed no evidence forchange and there were no reported fish kills. There were noincidents of toxicity in bivalve mollusc tissue.The final classification is ofa Non Problem Area (mediumconfidence), because in spite of nutrient enrichment and acceleratedgrowth, there is high confidence that there is no evidence ofundesirable disturbance, and that PA status is not justified..NPANutrients(1999-2006)Biomass(1999-2006)National Report on the Eutrophication Status of UK watersApril 200828AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassificanAppraisal of all relevant information (concerning the harmonisedassessment criteria their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI Ca - O2- At -DI + Ps - Ck -Northeast Irish SeaNP - Mp - OcNPA•The area is assessed as showing evidence of nutrient enrichment,(low confidence). Winter DIN exceeded the threshold in 3 out of5 years but N/P ratios did not.•The area is assessed as showing evidence of no accelerated growth(high confidence) as chlorophyll 90thpercentiles were consistently<15 μg l-1.•The area is assessed as showingevidence of no undesirabledisturbance (high confidence). Phytoplankton indices did notexceed thresholds. DO was consistently >4 mg l-1. There were norecorded fish kills and zoobenthos data provide evidence of nochange in community structure. There were no incidents oftoxicity in bivalve mollusc tissue.The final classification is of the northeast Irish Sea as aNon-ProblemArea (high confidence), based on evidence that in spite of nutrientenrichment, there was no evidence of accelerated growth orundesirable disturbance.NPANutrients(1999-2005)Biomass(1999-2006)National Report on the Eutrophication Status of UK watersApril 200829AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassificanAppraisal of all relevant information (concerning the harmonisedassessment criteria their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2- At -DI + Ps - Ck -Liverpool Bay (areaof particularcontinuing interestNP - Mp - OcNPAFollowing the 2002 application of the Comprehensive Procedure thisarea was subject to enhanced monitoring and surveillance.•This area is assessed as showing evidence of nutrient enrichment(high confidence). Winter DINexceeded the threshold, althoughDIN/DIP ratios did not.•The area is assessed as showing evidence of no accelerated growth(medium confidence).The chlorophyll 90thpercentiles were >15μg l-1in 2004, but <15 μg l-1in more recent years.•There is evidence of no undesirable disturbance (high confidence).The phytoplankton indicator was below the threshold and N:Siwould not favour flagellate growth. There are no macroalgaeblooms above the threshold. DO was consistently >4 mg l-1. Thezoobenthos showed no evidence for change and there were noreported fish kills. There were no incidents of toxicity in bivalvemollusc tissue.The final classification is of a Non Problem Area (high confidence),based on evidence that in spite ofnutrient enrichment there was goodevidence that there was no accelerated growth or undesirabledisturbance.NPANutrients(1999-2006)Biomass(1999-2005)National Report on the Eutrophication Status of UK watersApril 200830AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassificanAppraisal of all relevant information (concerning the harmonisedassessment criteria their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2- At -DI + Ps - Ck -Bristol ChannelNP + Mp - OcNPA•The area is assessed as nutrientenriched (medium confidence).Winter DIN and DIN/DIP ratios exceeded the threshold in the 3years with sufficient data.•The area is assessed as showing evidence of no accelerated growth(high confidence), with chlorophyll 90thpercentiles below thethreshold.•Bristol Channel is assessed (high confidence) as showing evidenceof no undesirable disturbance. The phytoplankton indicator andopportunistic macroalgal growth levels were below theirthresholds. DO was consistently > 4 mg l-1. The zoobenthosshowed no evidence for change and there were no reported fishkills. There were no incidents of toxicity in bivalve mollusctissue.The final classification of the Bristol Channel is of a Non-ProblemArea (high confidence), based on evidence that in spite of nutrientenrichment, there is strong evidence that there was no acceleratedgrowth or undesirable disturbanceNPANutrients(1999-2004)Biomass(1999-2004)National Report on the Eutrophication Status of UK watersApril 200831AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassificanAppraisal of all relevant information (concerning the harmonisedassessment criteria their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI Ca - O2- At -DI + Ps - Ck -Eastern EnglishChannelNP + Mp - OcNPA•This area is assessed as showing evidence of nutrient enrichment,(medium confidence). WinterDIN exceeded the thresholds inwaters 30 – 34.5 salinity, but in only one year in >34.5 salinity.•The area is assessed as showing no evidence of accelerated growth(low confidence). Chlorophyll 90thpercentiles were belowthresholds, except in 2002 in 30 – 34.5 salinity. Chlorophyllmeans were below thresholds.•There is evidence of no undesirable disturbance (mediumconfidence). Phytoplankton indices did not exceed the thresholdand there were no excessive opportunistic macroalgal blooms.DO was consistently >4 mg l-1. There have been no recorded fishkills and zoobenthos data did not indicate long-term change.There were no incidents of toxicity in bivalve mollusc tissue.The final classification is of the east English Channel as a NonProblem Area (medium confidence), based on evidence that in spite ofnutrient enrichment, there was noaccelerated growth or undesirabledisturbance.NPANutrients(1999-2006)Biomass(1999-2003)National Report on the Eutrophication Status of UK watersApril 200832AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassificanAppraisal of all relevant information (concerning the harmonisedassessment criteria their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI Ca - O2- At -DI + Ps - Ck -Solent (area ofparticularcontinuing interest)NP + Mp - OcNPAFollowing the 2002 application of the Comprehensive Procedure thisarea was subject to enhanced monitoring and surveillance.•The area is assessed as nutrient enriched (high confidence), withwinter DIN in waters <34.5 salinity exceeding the threshold.•The area assessment is of noaccelerated growth (mediumconfidence). Chlorophyll 90thpercentiles did not exceed thethresholds in 5 out of 6 years.•The area is assessed as showing no undesirable disturbance(medium confidence). Phytoplankton indices remained belowthresholds. DO was consistently >4mg l-1. There were no fish killsand no toxicity in bivalve mollusc tissue.In conclusion, the Solent has the final classification of a Non-ProblemArea (medium confidence), based on evidence that in spite of nutrientenrichment, there was no accelerated growth or undesirabledisturbance.NPANutrients(1999-2005)Biomass(1999-2004)National Report on the Eutrophication Status of UK watersApril 200833AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonised assessmentparameters, their respective assessment levels and the supportingenvironmental factors).The level of confidenceplaced in the evidenceused to assess the various categoriesand the overall conclusion are alsogiven (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2- AtDI - Ps ? Ck -SolwayNP - Mp - OcNPA•There are sufficient nutrient data todemonstrate that there is no evidenceof nutrient enrichment (high confidence).•There are limited data showing that chlorophyll concentrations did notexceed assessment criteria on surveys between 2001 and 2005, givinglow confidence in the conclusion thatthere is no evidence of acceleratedgrowth.•There is low confidence in the lack of evidence of undesirabledisturbance, due to the limited data. The phytoplankton data werequalitative rather than quantitative so the new assessment criterion couldnot be used. However, the waters are well oxygenated and there wasevidence of no fish or zoobenthos kills.The final assessment of the Solwayis as a Non-Problem Area (mediumconfidence), based on strong evidenceof no nutrient enrichment and someevidence that there was no acceleratedgrowth or undesirable disturbance.NPA 2001 – 2005National Report on the Eutrophication Status of UK watersApril 200834AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonised assessmentparameters, their respective assessment levels and the supportingenvironmental factors).The level of confidenceplaced in the evidenceused to assess the various categoriesand the overall conclusion are alsogiven (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2- AtDI + Ps ? Ck -Clyde estuary(area ofparticularcontinuinginterest)NP - Mp - Oc -PPA•There is evidence of nutrient enrichment (high confidence), as winterDIN exceeded the assessment threshold. However, the N/P ratio did notexceed the threshold.•There are sufficient chlorophyll data to give high confidence that there isno evidence of accelerated growth.•There is low confidence in the evidenceof undesirable disturbance due tovery limited phytoplankton data, however the existing data suggest thatthe criterion would not be exceeded. The low dissolved oxygenconcentrations at the head of the estuary during summer are related toinputs of urban wastewater rather than eutrophication. There is evidenceto show that measures taken to reduce these discharges have led to anincrease in diversity and abundance of zoobenthos in the estuary. Therewas evidence of no fish or zoobenthos kills since 1990.The final assessment of the Clyde estuary is as a Non-Problem Area (mediumconfidence), based on evidence that in spite of nutrient enrichment, there isstrong evidence that there was no accelerated growth and evidence to showthere was no undesirable disturbance.NPA2001- 2005National Report on the Eutrophication Status of UK watersApril 200835AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonised assessmentparameters, their respective assessment levels and the supportingenvironmental factors).The level of confidenceplaced in the evidenceused to assess the various categoriesand the overall conclusion are alsogiven (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2- At -DI - Ps - Ck -Inner Firth ofClydeNP - Mp - Oc -NPA•There is no evidence of nutrientinputs increasing. There are sufficientwinter nutrient data to give high confidence that thereis no evidence ofnutrient enrichment.•There are sufficient summer chlorophyll data to give high confidencethat there is no evidenceof accelerated growth.•The lack of suitable phytoplankton data gives low confidence in theconclusion of no undesirable disturbance. There is no evidence ofalteration of the phytoplankton community. Macrophyte growth isbelow the assessment criterion. The waters are well oxygenated andthere was evidence of no zoobenthos or fish kills. This is not acommercial shellfish area, so there have been no mussel infectionevents.The final assessment of the Inner Firth of Clyde is as a Non-Problem Area(high confidence), based on strong evidence of no nutrient enrichment oraccelerated growth and evidence ofno undesirable disturbanceNPA2001-2005National Report on the Eutrophication Status of UK watersApril 200836AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonised assessmentparameters, their respective assessment levels and the supportingenvironmental factors).The level of confidenceplaced in the evidenceused to assess the various categoriesand the overall conclusion are alsogiven (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2- At -DI + Ps - Ck -Forth estuaryNP - Mp - Oc -NPA•Winter DIN exceeded the assessmentcriterion’s threshold in 6 yearsbetween 1983 and 2005, but anthropogenic nutrient inputs havedecreased since 1991. The estuaryis assessed as enriched (mediumconfidence).•Summer chlorophyll dataexceeded the assessment criterion once in1997, but remained below the threshold during 2001 – 2005 assessmentperiod, so there is no evidence of accelerated growth (high confidence).•There were insufficient data to apply the phytoplankton communityassessment tool. Low dissolved oxygen concentrations in the turbiditymaximum in the upper estuary result from the degradation ofresuspended terrigenous organic matter in the water column. There wasevidence of no fish kills since the early 1990s. This is not a commercialshellfish area, so there have beenno mussel infection events. Theconclusion is that there is no undesirable disturbance (mediumconfidence).The final assessment of the ForthEstuary is as a Non-Problem Area(medium confidence), based on evidencethat in spite of nutrient enrichment,there is strong evidence that there was no accelerated growth and evidence toshow there was no undesirable disturbance.NPA2001-2005National Report on the Eutrophication Status of UK watersApril 200837AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonised assessmentparameters, their respective assessment levels and the supportingenvironmental factors).The level of confidenceplaced in the evidenceused to assess the various categoriesand the overall conclusion are alsogiven (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2- At -DI + Ps - Ck -Tay estuaryNP + Mp - Oc -NPA•Winter DIN exceeded the assessment criterion on 2 out of 6 years. TheN/P ratio exceeded the threshold in saline waters in 1997, 1999 and2000, but has not exceeded during the 2001 – 2006 assessment period.Nutrient inputs from wastewater discharges are low and have decreasedover the study period. The area is assessed as enriched (mediumconfidence).•Chlorophyll was measured at 10 fixed stations on axial surveys duringthe summer (June – August) in 2001 – 2005, inclusive.Chlorophyllexceeded the assessment criterion in2003 due to localised mid-estuarinepeak, but was well below the assessment criterion in all other years.The area is assessed as having no accelerated growth (low confidence).•It was not possible to use the quantitative assessment criterion forphytoplankton; however, qualitative assessment indicated noundesirable disturbance. There were sufficient data to conclude thatwaters are well oxygenated. Therewas evidence of no zoobenthos orfish kills. Macroalgae growth was not extensive. Overall there is noevidence of undesirable disturbance (medium confidence).The final assessment of the Tay estuary is a Non-Problem Area (mediumconfidence), based on evidence that in spite of nutrient enrichment there isno evidence of accelerated growthand undesirable disturbance.NPA2001-2005National Report on the Eutrophication Status of UK watersApril 200838AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonised assessmentparameters, their respective assessment levels and the supportingenvironmental factors).The level of confidenceplaced in the evidenceused to assess the various categoriesand the overall conclusion are alsogiven (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2- At -DI + Ps - Ck -Eden estuaryNP + Mp - Oc -NPA•Winter DIN and N/P ratios exceededtheir assessment criteria. Theestuary is designated as enriched with nutrients (high confidence).•Chlorophyll concentrations were low asphytoplankton growth is limitedby the high flushing rate. There islow confidence in the conclusion ofno evidence of accelerated growth, as the data are limited.•Estimates of macroalgal cover are limited to 2004 when the assessmentcriteria were not exceeded. The waters were well oxygenated and therewas evidence of no zoobenthos or fish kills. The benthic community didnot appear to be modified. This is not a commercial shellfish area, sothere have been no mussel infection events. There is evidence ofabsence of undesirable disturbance (medium confidence).The final assessment of the Eden Estuary is as a Non-Problem Area (mediumconfidence), because in spite of nutrientenrichment there is some evidenceto show there was no accelerated growth and reasonable evidence to showthere was no undesirable disturbance.NPA2001-2005National Report on the Eutrophication Status of UK watersApril 200839AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonised assessmentparameters, their respective assessment levels and the supportingenvironmental factors).The level of confidenceplaced in the evidenceused to assess the various categoriesand the overall conclusion are alsogiven (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2- At -DI + Ps - Ck -South Eskestuary(MontroseBasin)NP + Mp + Oc -PA•Winter DIN and N/P ratios exceeded the assessment criteria. The area isconsidered to be nutrient enriched (high confidence).•Chlorophyll concentrations were low and there are sufficient data togive medium confidence in the evidence of no accelerated growth.•There was no evidence of modification of the phytoplanktoncommunity. Estimates of opportunistic green algal cover in theintertidal area exceeded the assessment criterion. The waters were welloxygenated. There was an abundant and diverse zoobenthos populationin the intertidal area and there wasevidence of no zoobenthos or fishkills. This is not a commercial shellfish area, so there have been nomussel infection events. There is no evidence of undesirabledisturbance (medium confidence).The final assessment of the South Esk estuary (Montrose Basin) is aPotential Problem Area (medium confidence), based onevidence of nutrientenrichment and accelerated growth ofopportunistic greenalgae, althoughthere is no evidence of undesirable disturbance.PPA2001-2005National Report on the Eutrophication Status of UK watersApril 200840AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonised assessmentparameters, their respective assessment levels and the supportingenvironmental factors).The level of confidenceplaced in the evidenceused to assess the various categoriesand the overall conclusion are alsogiven (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca + O2- At -DI + Ps - Ck -Ythan estuaryNP + Mp + OcPA•Nitrogen concentrations in the river Ythan were high, so winter DIN andthe N/P ratio exceeded respective thresholds, indicating enrichment(high confidence).•Summer chlorophyll exceeded the assessment criteria (high confidence).•There was no evidence of modification of the phytoplanktoncommunity. The Ythan estuary was designated as a Nitrate VulnerableZone in 2000 on the basis of extensive growth of macrophytes coveringthe intertidal area. The waterswere well oxygenated and there wasevidence of no zoobenthos or fish kills. This is not a commercialshellfish area, so there have beenno mussel infection events. Theassessment is of no undesirabledisturbance (medium confidence).The Comprehensive Procedure assessment indicates that the designation ofthe Ythan Estuary as a Problem Area purely on the basis of it being a NVZmay be somewhat precautionary, asalthough there is strong evidence ofnutrient enrichment and accelerated growth, there is reasonable evidence ofno undesirable disturbance, which, overall would lead to classification as anon problem area or potential problem area.PA2001-2005National Report on the Eutrophication Status of UK watersApril 200841AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonisedassessment parameters, their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca + O2- At -DI + Ps ? Ck -Inner Belfast LoughNP - Mp ? OcPAThe Inner Belfast Lough was designated as a UWWTD ‘sensitive area’in 2001, and as described in section 4.2, such waters have beenautomatically designatedas Problem Areas orPotential problem Areasunder the OSPAR Comprehensive Procedure. The assessment belowuses the CP assessment to check this policy.•The Inner Lough is enriched in nutrient concentrations (highconfidence), although there is evidence that reductions in nutrientinputs over the last five years have resulted in improvements.•There is still some evidence of accelerated growth on occasions inthe chlorophyll andin-situfluorescence data, (high confidence).•There has been evidence of undesirable disturbance to the balanceof organisms (medium confidence). Toxin-producing algae andcysts have been recorded in the1990s. There are no macroalgaerecords. DO concentrations are consistently high. There has been astep change improvement in benthic invertebrate faunal population,linked to the reductions in organic carbon as a result of improvedeffluent treatment and the consequent reduction in nutrients. Nofish kills have been recorded.With the current location of WWTWoutfalls, this will remain aseither a Problem Area, or possibly a Potential Problem Area under theComprehensive Procedure in the future (high confidence).PANutrients(1993-2005)Biomass(2002-2006)Phytoplanktonspp. (1998-2002)National Report on the Eutrophication Status of UK watersApril 200842AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonisedassessment parameters, their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2- At -DI - Ps - Ck -Outer Belfast LoughNP - Mp - OcNPA•The Outer Lough is not currently enriched with nutrients (highconfidence).•There is no evidence of acceleratedalgal growth. There is evidenceof a reduction in chlorophyll concentrations throughout the Loughfromin-situmonitoring over the last 10 years (high confidence).Actual chlorophyll concentrations fall below the threshold value in2004 – 2006.•There is no evidence of excessivegrowth of macroalgae. Dissolvedoxygen concentrations are consistently >8 mg l-1,i.e. well abovethe critical threshold. Zoobenthos data did not indicate long-termchange. There is no evidence of an undesirable disturbance (highconfidence).The final assessment of the Outer Belfast Lough is as a Non-ProblemArea (high confidence); based on strong evidence that there was nonutrient enrichment, no acceleratedgrowth and no undesirabledisturbance.NPANutrients(1990-2005)Biomass(1991-2005)National Report on the Eutrophication Status of UK watersApril 200843AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonisedassessment parameters, their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2- At -DI + Ps - Ck -Carlingford LoughNP + Mp - OcNPA•There is some evidence of nutrient enrichment but over a longertime scale nutrient concentrations are not elevated and inputs arenot increasing (medium confidence).•There is no evidence of acceleratedgrowth of algae.Although thewater sampling strategy changed in 1998 to winter only, anin-situbuoy has now been installed.•There are no nuisance phytoplankton species and only one toxinproducing algae incident over the period. No excessive macroalgalgrowth. Dissolved oxygen is typically >8 mg l-1i.e. well above thecritical threshold. There are noimpacts on fish or zoobenthoscommunities. There is no evidence of undesirable disturbance(high confidence).The final assessment of Carlingford Lough is as a Non-Problem Area(medium confidence) based on evidence that nutrient enrichment isdecreasing, some evidence to show that there is no accelerated growthand strong evidence to show there is no undesirable disturbance.NPANutrients(1991-2003)Biomass(1991-2001)National Report on the Eutrophication Status of UK watersApril 200844AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonisedassessment parameters, their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2+ At -DI + Ps ? Ck -Foyle Estuary &LoughNP + Mp ? OcPA•There is some evidence of enrichment of nitrogen on occasions andN/P ratios are elevated(high confidence).•There is evidence of acceleratedgrowth in the chlorophyll andfluorescence data from anin-situbuoy (medium confidence).•Phytoplankton nuisance species levels remained low and toxinproducing algae were recorded but did not result in a shellfish toxinevent. Dissolved oxygen is consistently above 6mg l-1throughoutboth the Lough and the estuary with the occasional dip in DOconcentrations in the most upstreamof the freshwater sites (mediumconfidence). There is no undesirable disturbance to the fish orzoobenthos communities. Opportunist macroalgae abundance islow (medium confidence).The final assessment of the Foyle Estuary and Lough is as a PotentialProblem Area (medium confidence inin-situmonitoring), based onevidence of nutrient enrichment, accelerated growth and limited evidenceof undesirable disturbance in the form of low dissolved oxygen values.PPANutrients(1990-2006)Biomass(1997-2006)National Report on the Eutrophication Status of UK watersApril 200845AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonisedassessment parameters, their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2- At -DI + Ps - Ck -Strangford Lough;northNP - Mp + OcPPA•Nutrient concentrations are elevated above the threshold, butDIN/DIP ratios are not. This isclassified as nutrient enriched(medium confidence).•Chlorophyll is low and only exceeds the threshold on a fewoccasions. There is no acceleratedgrowth (high confidence).•There are no exceptional occurrences in the phytoplankton data.Species richness of macroalgae isreduced in the north end of theLough, with an increased abundance ofEnteromorphaspp.Dissolved oxygen is predominantly >6 mg l-1. Zoobenthos data showan improvement in the community to good/high ecological status.There is considered to be some evidence of undesirable disturbancegiven thatEnteromorphaspp is taking over the ecological niche oftheZosteraspp. beds (medium confidence).The north end of Strangford Lough is exhibiting some signs ofdisturbance. The final assessment of the Strangford Lough North is as aPotential Problem Area (medium confidence), based on evidence ofnutrient enrichment (medium confidence), accelerated growth (mediumconfidence) and limited evidence of undesirable disturbance (mediumconfidence) in the form of changing angiosperm/macroalgaedominance.PPANutrients(1994-2005)Biomass(1990-2005)National Report on the Eutrophication Status of UK watersApril 200846AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonisedassessment parameters, their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI Ca - O2- At -DI - Ps - Ck -Strangford Lough;southNP - Mp - OcNPA•Nutrient concentrations and DIN/DIP ratios are not elevated,though there are few recent data (medium confidence).•Chlorophyll is low and rarely exceeds the threshold(highconfidence).•There was only one, short-lived exceedance inDinophysisspp.(2004) in the phytoplankton data. This area supports a highdiversity of macroalgal species and benthic infaunal qualityfluctuates between good and high status. DO is predominantlybelow the threshold of 6 mg l-1. The zoobenthos community isundisturbed. There have been no recorded incidents of toxicity inbivalve mollusc tissue in the LoughThe final assessment of Strangford Lough South is as a Non-ProblemArea (high confidence), based ongood evidence that nutrientenrichment and accelerated growth donot occur, andstrong evidenceto show there is no undesirable disturbance.NPANutrients(1994-2004)Biomass(1990-2005)National Report on the Eutrophication Status of UK watersApril 200847AreaCategory IDegree ofnutrientenrichmentCategoryIIDirecteffectsCategory III and IVIndirect effects/ otherpossible effectsInitialclassnAppraisal of all relevant information (concerning the harmonisedassessment parameters, their respective assessment levels and thesupporting environmental factors).The level of confidence placed inthe evidence used to assess the various categories and the overallconclusion are also given (see section 3.2 for explanation).FinalclassnAssessmentperiodNI - Ca - O2- At -DI - Ps - Ck -Larne LoughNP - Mp ? OcNPA•Winter nutrient concentrationswithin the Lough are close tobackground concentrations for the Irish Sea. DIN/DIP ratios arenot elevated (high confidence).•Chlorophyll is consistently < 6μg l-1throughout the summer andconcentrations cannot be considered to be elevated. However,there are no data since 2002 (medium confidence).•There have been no occurrences of algal scums (e.g.Phaeocystis), nuisance algal blooms or toxicity in bivalvemollusc tissue. Dissolved Oxygen concentrations are consistently> 6 mg l-1. The benthic invertebrate community are nowconsidered consistent with unpolluted or normal conditions.There is no undesirable disturbance (high confidence).The final assessment of Larne Lough is as a Non-Problem Area (highconfidence) based on good evidence that nutrient enrichment andaccelerated growth do not occur, andstrong evidence to show there isno undesirable disturbanceNPANutrients(1993-2003)Biomass(1992-2002)

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## 48 

# 5 Comparisons with European eutrophication related

policies

The UK has been active in the development of systems for assessment of sensitive areas

(eutrophic) under the Urban Waste Water Treatme nt Directive and polluted waters (eutrophic)

under the Nitrates Directive, including assessment of waters that may become eutrophic. The

starting point for all classification schemes is th e definition of eutrophication, which has a

consistent formulation between the EC Direc tives and the OSPAR strategy. As a result all

classification methods are based on a similar set of criteria. The assessment methodology,

however, differs and in the case of the Comprehensive Procedure Assessment may lead to a

different outcome. This is described in section 6.2.2, below.

The Comprehensive Procedure Assessment is not carried out in isolation. There has been

significant development of assessment methodology in the last few years driven by the need

to assess ecological status under the Water Fram ework Directive, which covers transitional

and coastal waters. We have actively sought to ensure that paramete r-based assessments for

both OSPAR and WFD are based on a common scien tific understanding. This has led us to

adopt some of the tools developed under th e Water Framework Directive implementation

strategy (for example for chlorophyll concentration and phytoplankton indicators) for

application in the Comprehensive Procedure.

However, the UK has not yet finalised the fu ll classification of waters using the tools

developed for the Water Framework Directive. This is work in progress and we are,

therefore, unable to compare and contrast this with the Comprehensive Procedure outcomes.

It is clear, subject to a few caveats, that the OSPAR Comprehensive Procedure provides a

reliable and scientifically robust classification of areas of the maritime region as Problem

Areas and Non-Problem Areas and could usefully contribute to the Initial Assessment that

will be required for the implementation of the new European Marine Strategy Directive.

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## 49 

# 6 Perspectives

6.1 Measures taken to address UK Problem Areas and Potential Problem Areas

6.1.1 Problem Areas and potential Problem Areas designated in 2002

As mentioned in Section 4.2, a number of sm all estuaries, harbours and loughs, which had

already been identified by the UK as either sensitive waters (eutrophic) leading to designation

as Sensitive Areas (SA) under the UWWT Directiv e, or as polluted waters leading to the

designation of Nitrate Vulnerable Zones (NVZ) under the Nitrates Directive were

automatically designated as OSPAR Problem Ar eas or Potential Probl em Areas in the UK

report on the first application of the OSPAR Comprehensive Procedure in 2002. These are

listed in the second column of Table 4 below.

Table 4: UK Problem Areas and Potential Pr oblem Areas reported to OSPAR in first

application of the Comprehensive Procedu re in 2002; sensitive areas (SA) under the

UWWT Directive and nitrate vulnerable zones (NVZ) under the Nitrates Directive

Assessment area OSPAR status

in 2002 Reason for

OSPAR status

Portsmouth Harbour PA SA

Chichester Harbour PA SA Langstone Harbour PA SA Pagham Harbour PA SA Loughor estuary PPA SA Seal Sands (Tees estuary) PA SA

Lindisfarne NNR area PA NVZ Holes Bay PA SA

Poole Harbour PPA SA & NVZ

The Fleet PPA NVZ Truro, Tresillian and Fal
estuaries PA SA & NVZ

Taw estuary PA SA & NVZ

Tawe PA SA Ythan estuary PA SA & NVZ Quoile Pondage (in Strangford Lough Catchment) PPA SA

Inner Belfast Lough & tidal Lagan impoundment PA SA

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## 50 6.1.2 Measures taken to reduce the inputs of Nutrients from UK Problem

Areas and Potential problem areas

Areas designated as Nitrate Vulnerable Zones under the Nitrates Directive

NVZs were originally designated in 1996 and covered approximately 8% of England’s land

area. Additional NVZs were designated in 2002 and brought the total coverage to

approximately 55% of England.

An Action Programme of measures has been im plemented by farmers within these NVZs to

reduce losses of nitrate from agricultural land. The Action Programme promotes best

practice in the use and storage of fertiliser and manure, and builds on the guidelines set out in

the ‘Code for Good Agricultural Practice for the Protection of Water’;

http://www.defra.gov.uk/farm/environment/cogap/

.

There are four key aspects to the Action Programme which require farmers to:

• Limit inorganic nitrogen fertiliser applica tion to crop requirements, after allowing

fully for residues in the soil and other sources.

• Limit organic manure applications to 170 kg ha -1 

## of total nitrogen each year averaged

over the area of the farm not in grass and 250 kg ha -1 

## of total nitrogen each year

averaged over the area of grass on the farm.

• On sandy or shallow soils not to apply slurry, poultry manures or liquid digested

sludge between 1 September and 1 November (grassland or autumn sown crop) or 1

August and 1 November (fields not in grass without autumn sown crop). The storage

capacity available for those animal manures which cannot be applied during the

autumn closed period must be sufficient to cover these periods unless other

environmentally acceptable means of disposal are available.

• Keep adequate farm records, including cropping, livestock numbers and the use of

organic manures and nitrogen fertilisers.

Four NVZs were designated in Scotland in 200 2, comprising 14% of the land area. They

incorporate areas earlier designated, one of which was the Ythan catchment.

In 1999 and 2003 Northern Ireland designated sev en small Nitrate Vulnerable Zones (NVZs)

due to elevated nitrate levels in groundwaters. In October 2004 a total territory approach to

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## 51 the implementation of the Directive was adopted in Northern Ireland due to eutrophication of

surface waters and the ‘Nitrates Action Programme Regulations (Northern Ireland) 2006’ (the

NAP Regulations) came into operation on 1 January 2007. The introduction of these

regulations meets Northern Ireland’s legal and environmental obligations and the ‘Phosphorus

(Use in Agriculture) Regulations (Northern Ire land) 2006’, which also became operational on

1 January 2007, support these obligations. These regulations bring into operation measures to

improve the use of nutrients on farms and as a result improve water quality throughout

Northern Ireland.

Some of the key measures in the NAP Regulations include:

• A closed period for the spreading of organic (15 Oct to 31 Jan) and inorganic

fertilisers (15 Sept to 31 Jan);

• A minimum livestock manure storage requirement (26 weeks for pig/poultry and 22

weeks for other livestock);

• A limit on the amount of nitrogen that can be applied to land from livestock

manures (170kg N ha -1 

## year -1 

## ); and

• The inclusion of nitrogen efficiency measures.

In addition to the measures described in action plans, Member States are required to carry out

effectiveness monitoring of the action plans. In Northern Ireland, the effectiveness of the

programmes is measured by:

• Monitoring surface (~600) and groundwater (~90) stations on a monthly basis for

compliance with the 50mg l -1



## • Trophic status monitoring of rivers, lakes and transitional/coastal waters, measuring

both chemical and biological determinands on a rolling programme.

• Detailed nutrient budgeting of catchments

• Intensive survey at targeted mini-catch ments, with known eutrophication problems

• Soil mineral N analysis

The studies outlined above are ca rried out in conjunction with other government laboratories.

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## 52 Waters Designated as Sensitive under th e Urban Wastewater Treatment Directive

The Urban Waste Water Treatment Directive (UWWTD) sets requirements for the collection,

treatment and discharge of urban wastewater and also establishes timetables for the

achievement of these standards according to the sensitivity of the waters.

The Directive requires that sewage being dischar ged to SAs should be subjected to tertiary

treatment to standards given in the Direc tive, within seven years of designation.

The SAs mentioned above were designated in 2002 or earlier. Appraisals of wastewater

treatment plants discharging into the SAs a nd the installation of remedial measures where

appropriate are either completed or underway, but a full report on how the various measures

have been implemented will not be available until after the seven ye ar deadline has been

reached in 2009.

Improvements in the ecology of the waters in Belfast Lough have already been noticed since

the installation of nitrogen removal at four wastewater treatment plants discharging into the

Lough.

More details on how the UK is working to achieve reductions in nitrogen inputs to the marine

environment can be found in the implementa tion reports for OSPAR Recommendations 88/2,

89/4 and 92/7 which can be found on the OSPAR website.

6.2 Outlook

6.2.1 Expected trends

Using data collected for the OSPAR Riverine Inputs and Direct Discharges survey we have

completed statistical trend analysis for four ar eas. There are no statistically significant trends

in the combined riverine and direct input of DIN from four major UK catchments: the Bristol

Channel, Liverpool Bay, Humber/Wash and the Th ames. The lack of trend may be explained

where measures have been taken, under EC Direc tives, by the long lag time in environmental

systems and by the possible confounding effects of environmental change. Experts have

indicated that, due to the large existing reservoi rs of nitrogen in soils and sediments, it could

be decades before measures such as improved agri cultural practice with respect to fertilizer

and manure use will begin to show measurable improvements in environmental quality. There

are circumstances where, in relation to manageme nt of point sources, environmental benefits

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## 53 can be realised quickly; for example, there is local evidence that inputs of phosphorus are

lower in recent years compared to previous times, resulting from the introduction of improved

urban waste water treatment.

There is a risk that climatic change may affect the eutrophication status of areas of UK waters

through either change in physical or biological process driven by warming, or by changing the

nutrient input through varying precipitation. Examples of possible change are described

below.

The depth of mixing at the continental shelf boundary determines the background

concentration of nutrients experienced across the shelf seas around the UK. This is known to

respond to storminess which is considered to be increasing due to climatic change and could

result in a change in the background nitrogen con centration. Such change is likely to be in a

narrow range with limited implication for our current assessments of coastal water

eutrophication status.

Taking account of realistic climate change scenarios (UKCIP02 Briefing Report, 2002) we

may expect the delivery of nutrients to change in estuarine and coastal areas, with higher

loadings in the winter and a reduction during the summer. The direct impact of this change

over many decades is difficult to predict and may form the subject of further investigation.

Changes in temperature affect phytoplankton ph ysiology and may result in shifts in species

composition of phytoplankton (McQuatters-Goll op, 2007) as well as affecting the duration

and strength of thermal stratification of the deeper (> 40 m) shelf seas. There is therefore

concern that the growth response of organisms to nutrient enrichment may change and that,

for example, deoxygenation of bottom waters in stratified regions may increase. It may be

that parts of the seas become more ‘susceptible’ to the effects of nutrient enrichment, but it is

also clear that distinguishing between cause and effect will become more difficult. We can

predict such changes using ecosystem models but we are currently building confidence that

these predictions form a good basis for management action.

Subject to the qualifications given in the a bove paragraphs, the expected status of UK

assessment areas is summarised in Table 5

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## 54 Table 5: Expected Eutrophication Status of UK waters examined under the OSPAR Comprehensive Procedure

Country Assessment area OSPAR 2002

assessment OSPAR 2008

assessment Expected

status

Northern North Sea NPA NPA

Southern North Sea NPA NPA Eastern English Coast NPA NPA East Anglia NPA NPA East English Channel NPA NPA

Solent NPA NPA

Bristol Channel NPA NPA Liverpool Bay NPA NPA England
and Wales

Northeast Irish Sea NPA NPA Clyde estuary NPA NPA Firth of Clyde NPA NPA Forth estuary NPA NPA Tay estuary NPA NPA Solway NPA NPA Scotland

Eden NPA NPA Carlingford Lough NPA NPA Larne Lough NPA NPA Strangford Lough South NPA NPA Northern

Ireland

Outer Belfast Lough NPA NPA Expected to
remain as non-problem areas, subject to significant
climatic changes

Lower Fal estuary [PA] 3



## Portsmouth & Chichester Harbours PA PA Langstone Harbour PA PA Pagham Harbour PA PA Medina estuary PA

Newtown Harbour PA Eastern Yar [PA] 1


## Loughor estuary PPA PA Hamble estuary PA Seal Sands (Tees estuary) PA PA

Lindisfarne NNR area PA PA Holes Bay PA PA

Poole Harbour PPA PPA

The Fleet PPA PPA Truro, Tresillian and Fa l estuaries PA PA Taw estuary PA PA

Tawe PA PA South Esk estuary (Montrose basin) PPA 4


## Ythan estuary PA PA Inner Belfast Lough & tidal Lagan impoundment PA PA Strangford Lough North PPA Estuaries
And
Harbours In England
Wales
Scotland
And
Northern
Ireland designated

as SAs or NVZs, or
“whole territory”
Under the

UWWT
and/or
Nitrates

Directive



## .

Foyle estuary and Lough PPA Measures being applied under
UWWT and/or
Nitrate Directives, in conjunction
where appropriate with any future
measures under the WFD, should lead to progress
towards NPA

status. However
the timeframe is
uncertain due to the complexities

of the science including the
effect of nutrient

reserves in soils
and sediments



## . (see para 6.2.1)

3 

### Status of areas in square brackets is provisional and dependent on form al designation under the Nitrates

Directives. UK will inform OS PAR when the position is clear.

4 

### the South Esk estuary (Montrose Basin) is not designated as an NVZ, but most of the catchment in which it is situated has been designated as an NVZ. Therefore, this area should benefit from the associated nitrogen
reductions.

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## 55 6.2.2 Improvement of assessments

There are three issues that come out of the peer review of our application of the

Comprehensive Procedure and that the UK belie ves would assist OSPAR to develop/refine

the procedure for future applications.

Algal toxicity and eutrophication . The first of these is the use of Category IV concerning

Other Possible Effects. Although we have included information about the incidence of

DSP/PSP toxicity in bivalve mollusc tissue, a nd added to this with readily available

information about the presence of toxin producin g algae, we do not think this information

adds anything to the overall classification of eutrophication status and in some cases might

provide a wrong classification. There is con tinuing scientific debate about the link between

nutrient enrichment and both the presence of TPA and toxicity in bivalve mollusc tissue.

There is evidence that TPA occur in regions where there is no anthropogenic nutrient

enrichment, e.g. along the Atlantic coasts of the UK. Until such time as there is clear

scientific justification we propose not to use TPA and the presence of toxicity in shellfish as

assessment criteria. The UK is commissioning a research project to address this question

together with other countries which will report in early 2009.

Adequacy of macrophyte tools . Although we have deve loped assessment methods for

macrophytes, including macroalgae, in shallow co astal and estuarine waters there is scope for

improving our quantitative assessment tools. Ther e has been considerable attention given to

this area in the work streams supporting th e implementation of the Water Framework

Directive (Scanlan et al ., 2006) and it will be several years before the adequacy of the new

tools is confirmed. OSPAR needs to ensure that it contributes to, and benefits from,

experience gained in applying th is ecological assessment tool.

Lack of clarity in the application of Category II . The most serious of the problems

identified, concerns the application of the Ca tegory II Harmonised Assessment Criteria where

there is a mix of criteria reflecting different asp ects of the overall definition of eutrophication.

It is clear that the indicators in Category I relate unambiguously to nutrient enrichment . It is

also clear that the criteria in Category III relate unambiguously to undesirable disturbance to

the balance of organisms or to the quality of the water . In contrast Category II contains

elements that relate to accelerated growth (e.g. chlorophyll and ma crophyte biomass) and to

undesirable disturbance to the balance of organisms or to the quality of the water (e.g.

phytoplankton indicator species and ‘shifts’ in the nature of the macroalgae/macrophytes).

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## 56 Our experience shows that this can lead to a s ituation where misclassification is possible. The

most concrete example is where in the Initial Cl assification there is a ‘+’ for Category I, a ‘+’

for Category II (relating only to chlorophyll) and a ‘–’ for Category III/IV. The combined

scores give a Problem Area Classification. This means that the area is nutrient enriched and

that there is accelerated growth but the final test for eutrophication – undesirable disturbance

to the balance of organisms or to the quality of the water – has not been met. According to

the definition of eutrophication this type of ar ea is a Non-Problem Area (or may be a Potential

Problem Area if there are increasing trends re lated to nutrients and chlorophyll). This

anomaly requires a change to the assessment sch eme by separating out those criteria relating

to undesirable disturbance from Category II.

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## 57 

# 7 Conclusions on the Eutrophica tion Status of UK Seas

The results of the latest, more robust, app lication of the OSPAR Comprehensive Procedure

which assesses the eutrophication status of UK sea s, generally confirms those of the first

application in 2002. The evidence revealed by the monitoring programmes clearly shows,

with a good degree of confidence, that the coastal and marine waters around the UK are Non

Problem Areas with respect to eutrophication and show no signs of undesirable disturbance.

However, the evidence confirms that there ar e a number of small estuaries, loughs and

harbours which are Problem Areas with respect to eutrophication, or are at risk due to factors

such as restricted circulation.

The overall classification results for the UK areas subject to the Comprehensive Procedure are

listed in Table 6 There are 19 areas classified as Non Problem Areas, 17 areas classified as

Problem Areas and 5 areas that are Potential Probl em Areas, with respect to eutrophication.

The status of these areas has been identified using the Comprehensive Procedure

methodology, or the Urban Waste Water Treatment Directive or the Nitrates Directive, where

theses directives were used in the origin al assessment of some areas (Table 6).

These areas fall into two categories.

1. Coastal and Offshore marine waters (salin ity >30) – which were identified as Non

Problem Areas in 2002 and remain Non Problem Areas. We are more confident in

the results of the current assessment, especia lly in the coastal areas identified in 2002

as areas of particular ongoing interest, due to enhanced monitoring and research

programmes that were designed to detect any adverse anthropogenic related changes

that could threaten the NPA status. These areas are East England, East Anglia,

Liverpool Bay and the Solent and the Clyde.

2. Restricted regions including estuaries, l oughs and harbours – some of which were

identified as Problem Areas or Potential Problem Areas in 2002 (see table 4 ).

Through the ongoing assessment programme re lated to the implementation of EC

Nitrates and Urban Wastewater Treatment Directives a further 5 Problem Areas and 3

Potential Problem Areas have been identified 5 

## . These are all small water bodies.

The possible impacts of climatic change on th e assessment have been considered and while

there may be a tendency, in some areas, to in crease the risk of nutrient enrichment related

5 

### The status for the Lower Fal Estary and the Eastern Yar is provisional, and is de pendent on formal designation

under the Nitrates Direct ive later in 2008. UK will inform OSPAR when the position is clear.

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## 58 effects in the seas, further work is required to help develop confidence in such prediction.

Currently predicted change would only become significant several decades into the future.

The second application of the Comprehens ive Procedure has helped develop our

understanding of the eutrophication status of UK waters, and the assessment methods for each

of the Harmonised Assessment Criteria from de velopments in the underpinning science and

parallel developments for the purposes of the Water Framework Directive. One of the

outcomes is a clear conclusion that several components of the overall assessment process

need to be refined, in order to come to a clearer and more robust conclusion reflecting the

definition of eutrophication.

Figure 5 is a map of these final classificati ons and Figure 6a and Figure 6b show the

assessment areas for Northern Ireland and Scotland on a smaller scale. Figure 6c presents a

small-scale map of the south coast of England in order that the classifications of estuarine

areas in this region are visible.

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## 59 Table 6: Final classification of UK areas

Country Assessment area OSPAR 2002 OSPAR 2008

Northern North Sea NPA NPA

Southern North Sea NPA NPA Eastern English Coast NPA NPA East Anglia NPA NPA East English Channel NPA NPA

Solent NPA NPA

Bristol Channel NPA NPA Liverpool Bay NPA NPAEngland and Wales –Coastal and offshore areas



## Northeast Irish Sea NPA NPA Lower Fal estuary [PA] 6



## Portsmouth & Chichester Harbours PA PA Langstone Harbour PA PA Pagham Harbour PA PA Medina estuary PA

Newtown Harbour PA Eastern Yar [PA] 7


## Loughor estuary PPA PA Hamble estuary PA Seal Sands (Tees estuary) PA PA

Lindisfarne NNR area PA PA Holes Bay PA PA

Poole Harbour PPA PPA

The Fleet PPA PPA Truro, Tresillian and Fal estuaries PA PA Taw estuary PA PAEngland and Wales – estuaries



## Tawe PA PA Clyde estuary NPA NPA Firth of Clyde NPA NPA Forth estuary NPA NPA Tay estuary NPA NPA Solway NPA NPA South Esk estuary (Montrose basin) PPA Ythan estuary PA PAScotland



## Eden NPA NPA Inner Belfast Lough & tidal Lagan impoundment PA PA Carlingford Lough NPA NPA Larne Lough NPA NPA Strangford Lough North PPA Strangford Lough South NPA NPA Outer Belfast Lough NPA NPANorthern Ireland



## Foyle estuary and Lough PPA

6 

## Status dependent on formal designation under the nitrates Directive

7 

## Status dependent on formal designation under the nitrates Directive

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## 60 Figure 5: Final classification for UK assessment areas.

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## 61 Figure 6: Map extracts of assessment areas in (a) Scotland, (b) Northern Ireland, and (c)

English south coast. c a b

### National Report on the Eutrophicati on Status of UK waters

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## 62 

# 8 References

CSTT (1994). Comprehensive studies for the purposes of Article 6 of DIR 91/271 EEC, the

Urban Waste Water Treatment Directive. P ublished for the Comprehensive Studies Task

Team of Group Coordinating Sea Disposal Monitoring by the Forth River Purification Board,

Edinburgh.

CSTT (1997). Comprehensive studies for the purposes of Article 6 & 8.5 of DIR 91/271 EEC,

the Urban Waste Water Treatment Directive, second edition. Published for the

Comprehensive Studies Task Team of Group Coordinating Sea Disposal Monitoring by the

Department of the Environment for Northern Ireland, the Environment Agency, the Scottish

Environmental Protection Agency and the Water Services Association.

Marine Environment Monitoring Group, (Cef as) (2004). UK National Marine Monitoring

Programme – second report (1999 – 2001). Cefas

McQuatters-Gollop A., Raitsos, D.E., Edwards, M., Pradhan, Y., Mee, L., Lavender, S.,

Attrill, M. 2007. A long-term chlorophyll da ta set reveals regime shift in North Sea

phytoplankton biomass unconnected to nutrient trends. Limnology and Oceanography

, 52(2):635–648.

Scanlan, C.M., Foden, J., Best, M.A. & Wells, E. (2007). The monitoring of opportunistic

macroalgal blooms for the Water Framework Directive. Marine Pollution Bulletin , 55: 162 –

171.

UKCIP02 Briefing Report (2002). Climate Change Scenarios for the United Kingdom. The

UKCIP02 Briefing Report, April 2002.

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## 63 

# 9 Annexes

9.1 Screening Review

After considering possible changes to the driv ers for nitrogen, including any measures taken

for national or European purposes, we scr eened the marine waters around the UK using a

simple approach based on winter nutrient concen trations. Winter nitrogen data (dissolved

inorganic nitrogen – DIN) from all availabl e surveys were used and where available

supplemented by information on TOxN derive d from SmartBuoys. SmartBuoys measure total

oxidised nitrogen (TOxN), but not ammonium so DIN data are not calculable. However,

examination of spatial data (sampled from ship-borne surveys) in an area 150 – 300 km 2



## around each SmartBuoy found that ammonium constituted <6% of DIN in > 90% of samples;

so SmartBuoy TOxN data slightly underestim ates spatial DIN data and may be used for

screening purposes.

Table 7: Summary results of the 2008 screen ing procedure for England and Wales.

Data were separated into spatial and temporal.

Mean winter DIN (spatial) & TOxN (SmartBuoy) ( μ M) for whole assessment period Spatial (NMMP, EA) Assessment area

Estuarine Coastal Offshore SmartBuoy (Cefas) Full

assessment?

Liverpool Bay 55.47 30.06 - 18.47 Yes

Northeast Irish Sea - 19.64 - - Yes
Cardigan Bay - 11.42 - - No

Bristol Channel 56.27 25.97 - - Yes

North Cornwall Coast - - 8.72 - No
SW England Coast - - 8.53 - No
East English Channel Coast 160.02 18.63 10.32 - Yes

Solent 142.20 30.73 17.24 - Yes
East Anglian Coast 43.95 31.13 19.35 23.99 Yes
Eastern English Coast 93.03 58.60 9.06 - Yes
NE England Coast 57.94 15.00 8.65 - No

Northern North Sea - - 6.01 - Yes

Southern North Sea - 25.42 10.16 7.02 Yes

Data were averaged over the 6-year assessment period. Winter nutrient concentrations

exceeding 15 μ M in coastal and offshore waters were put forward for assessment under the

OSPAR comprehensive procedure. The excepti on was the Northern North Sea area, which

did not exceed the DIN threshold but was exam ined due to interest in relation to the

contiguous areas to the east. It has been put forward for a full assessment due to trans-

### National Report on the Eutrophicati on Status of UK waters

April 2008 

## 64 boundary transport debate. The outcomes of the screening procedure for defining the areas

considered to be non-problem are set out in Table 7.

### National Report on the Eutrophicati on Status of UK waters

April 2008 

## 65 9.2 Thresholds used in the OSPAR comprehensive procedure

9.2.1.1 Phytoplankton

Table 8 is a summary of individual phytopla nkton indices’ thresholds and the summary

equation relating to the occurrences of elevated phytoplankton taxa counts within a whole

population. The overall index is composed of counts of the four attributes within the tool.

Samples are taken in the growing season between April and September. The

GOOD/MODERATE boundary equates to the pr oblem/non problem threshold for OSPAR

CP. Phytoplankton data were extracted from the UK phytoplankton database. These data

have been compiled for WFD purposes, and are geographically linked to WFD transitional

(estuarine; salinity <30) and coastal (salinity 30-34) water bodies.

Table 8: Summary of phytoplankton indices (IE) relating to the occurrences of elevated

taxa counts within a whole population

Normative

definition Index Equation – {SUM [T] + [P] + [S]+[CHL]/4} *100 Phytoplankton

assessment

<25% Threshold not

exceeded 

## Phytoplankton

abundance I E 

## I E 

## : s um of the occurrence of any species (> 10 6 

## ), plus Phaeocystis (>10 6 

## ), plus total cell counts (>10 7 

## ) and counts of chlorophyll > 10ug/l over a five year period >25% Threshold

exceeded



## 9.2.1.2 Macrophytes (macroalgae)

The proposed thresholds for assessment of areas with macroalgal bloom events are set out in

Table 9. They have been adapted from Wa ter Framework Directive macroalgal bloom

metrics (Scanlan et al ., 2007).

Table 9: Thresholds for assessment of macroalgae blooms under the OSPAR CP



# Macroalgal biomass Macroalgal cover Macroalgae

assessment
<500g/sqm <15% Threshold not exceeded 

# >500g/sqm >15% Threshold exceeded

### National Report on the Eutrophicati on Status of UK waters

April 2008 

## 66 9.2.1.3 Dissolved oxygen

Table 10 sets out the standards for dissolved oxygen (DO) levels during the growing season,

as proposed for WFD assessment and these have been simplified for OSPAR. Regions are

deemed to have exceeded the OSPAR threshold where DO levels is below 4 mg l -1 

## on more

than 5% of sampling occasions during the growing season.

Table 10: Proposed dissolved oxygen sta ndards for naturally ventilated layers (or

rapidly exchanged stratified waters) of transitional and coastal waters.

Marine 5%ile Objectives DO

assessment

≥ 5.7 mg l -1 

## All life-stages of salmonids and transitional fish

≥ 4.0 <5.7 mg l -1 

## Presence of salmonids and transitional fish Threshold not

exceeded


## ≥ 2.4 <4.0 mg l -1 

## Most life-stages of non-salmonid adults

≥ 1.6 <2.4 mg l -1 

## Presence of non-salmonids, poor survival of salmonids

<1.6 mg l -1 

## No salmonids present marginal survival of resident species Threshold

exceeded



## 9.2.1.4 Zoobenthos/benthic invertebrates and reported fish kills

Sea Fisheries Commissions were contacted fo r data on incidents of fish kills.

Under the Water Framework Directive benthic metrics, methods and thresholds are being

established but this is work in progress and resu lts are not yet available. Monitoring of the

benthos has been regularly undertaken by Cefas, though it has not been directly targeted at

assessment of eutrophication. Where releva nt, results from the UK National Marine

Monitoring Programme (NMMP) second report (MEMG Cefas, 2004) and Cefas’ Defrafunded research and development study of “The Benthic Ecology of the Western North Sea”,

have been used in area reports.

9.2.1.5 Toxin levels in bivalve mollusc tissue

For the assessment of bivalve mollusc tissue pois oning events, the procedure set out in the

Water Framework Directive characterisation report was used. Table 11 sets out the thresholds

for OSPAR exceedance, based on the percentage of bivalve mollusc tissue samples failing to

meet FSA standards. As further supporting ev idence, TPA concentrations in water samples

were also assessed against the same threshold of 10% of samples exceeding the FSA

permitted levels.

### National Report on the Eutrophicati on Status of UK waters

April 2008 

## 67 Table 11: Assessment criteria for Category IV – occurrence of toxicity in bivalve

mollusc tissue and presence of toxin producing algae.

Toxin Maximum permitted

levels TPA species Shellfish poisoning Action Level (cells l -1 

## )

PSP 80 μ g per 100 g
flesh Alexandrium

tamarense PSP Present

DSP Presence in
flesh Dinophysis spp. DSP 100

Prorocentrum lima DSP 100 ASP 20 μ g per g flesh Pseudonitzschia spp. ASP 150,000 Proportion of failed sampl es (whichever was most for ASP/PSP/DSP) Toxicity in bivalve mollusc

tissue and TPA assessments

<10 % Threshold not exceeded

>10 % Threshold exceeded