Benthic habitats
Assessment of progress towards the achievement of Good Environmental Status for benthic biodiversity and seafloor habitats.
Extent to which Good Environmental Status has been achieved
The achievement of Good Environmental Status is uncertain for intertidal and soft sediment habitats. The levels of physical damage to soft sediment habitats are considered to be consistent with the achievement of Good Environmental Status in UK waters to the west of the Celtic Seas, but not in the Celtic Seas or in the Greater North Sea.
For sublittoral rock and biogenic habitats Good Environmental Status has not yet been achieved.
How progress has been assessed
In the UK Marine Strategy Part One (HM Government, 2012) the UK set out “Characteristics of Good Environmental Status” for biodiversity and seafloor integrity:
“At the level of the Marine Strategy Framework Directive sub-regions, and in line with prevailing conditions, the loss of biodiversity has been halted and where practicable, restoration is underway: The abundance, distribution, extent and condition of species and habitats in UK waters are in line with prevailing environmental conditions as defined by specific targets for species and habitats. Marine ecosystems and their constituent species and habitats are not significantly impacted by human activities such that the specific structures and functions for their long-term maintenance exist for the foreseeable future. Habitats and species identified as requiring protection under existing national or international agreements are conserved effectively through appropriate national or regional mechanisms.”
“Seafloor habitats (physically and structurally) are both productive and sufficiently extensive at the level of the Marine Strategy Framework Directive sub-regions, to carry out natural functionality, including the necessary ecological processes which underpin ecosystem goods and services, and are capable of supporting a healthy and sustainable ecosystem for the long term.”
The extent that Good Environmental Status, as articulated in the criteria for the Commission Decision 2010/447/EU, (European Commission, 2010) had been achieved, was assessed using targets set out for benthic habitats in the UK Marine Strategy Part One (HM Government, 2012) (see Table 1). These targets were set for benthic habitats under 5 relevant criteria: Habitat Distribution, Habitat Extent, Habitat Condition, Physical Damage, and Condition of the Benthic Community.
The UK environmental targets in the UK Marine Strategy Part One (HM Government, 2012) were split between sediment habitats and rock and biogenic habitats due to the different characteristics and sensitivities of these 2 broad habitat types. However, to provide a clear and transparent presentation on the progress of Good Environmental Status so far, this assessment has separated intertidal (littoral) habitats from sub-tidal (sublittoral) habitats. This split reflects the level of development of indicators available for the assessments, the use of tools developed under Water Framework Directive (European Commission, 2000) legislation, and the geographical applicability of indicators. Therefore, the assessments are divided into the following habitat types:
- Sublittoral rocky and biogenic habitats (Table 1)
- Soft sediment habitats (Table 2)
- Intertidal habitats - due to the limited amount of data used in the indicator assessments, it has not been possible to undertake a fully integrated assessment on the Good Environmental Status characteristics, but instead, an overall qualitative assessment was done using the results from the combination of the criterion and indicator targets. (Table 3)
The results of each indicator assessment were used to evaluate the extent that the targets have been met.
Table 1. Summary of the UK environmental targets and associated indicators for rocky and biogenic habitats.
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UK Targets |
Indicators that have been used |
Spatial coverage |
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Habitat Distribution At the scale of the Marine Strategy Framework Directive sub-regions, rock and biogenic reef habitats are stable or increasing: For all listed (special) and predominant habitat types, range and distribution are stable or increasing and not smaller than the baseline value (Favourable Reference Range for Habitats Directive habitats). |
None at present |
N/A |
|
Habitat Extent At the scale of the Marine Strategy Framework Directive sub-regions, rock and biogenic reef habitats are stable or increasing: For all listed (special) and predominant habitat types area is stable or increasing and not smaller than the baseline value (Favourable Reference Area for Habitats Directive habitats). |
Area of subtidal biogenic structures' but only for 'Zostera beds' and 'Modiolus reefs' Please note that both biogenic habitats were assessed under the same target. See sections below for further information |
UK level, Sublittoral areas |
|
Habitat condition, Physical damage, and Condition of the benthic community At the scale of the Marine Strategy Framework Directive sub-regions, rock and biogenic reef habitats are not significantly affected by human activities: For all listed (special) and predominant habitat types the area of habitat in poor condition (as defined by condition indicators) must not exceed 5% of the baseline value (Favourable Reference Area for Habitats Directive habitats). |
OSPAR Extent of Physical Damage to Predominant seafloor habitats-UK |
Sub-divisions of each UK Marine Strategy Framework Directive sub-region (Celtic Seas and Greater North Sea) and in UK waters within adjacent OSPAR Regions I (Arctic), IV (Bay of Biscay) and V (Wider Atlantic). |
Table 2. Summary of the UK environmental targets and associated indicators for sediment habitats.
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UK Targets |
Indicators that have been used |
Spatial coverage |
|
Habitat Distribution Predominant habitat types:
|
None at present |
N/A |
|
Habitat Extent Predominant habitat types:
Listed (special) habitat types:
|
None at present |
N/A |
|
Habitat condition, Physical damage, and Condition of the benthic community Predominant sediment habitat types:
Listed (special) sediment habitat types:
* Please note these three habitats are now included under intertidal. See intertidal section |
|
BH3: sub-divisions of each UK Marine Strategy Framework Directive sub-region (Celtic Seas and Greater North Sea) and in UK waters within adjacent OSPAR Regions: I (Arctic), IV (Bay of Biscay), and V (Wider Atlantic). Water Framework Directive: Sublittoral areas - UK Charting Progress 2 Regional Seas which cover Celtic Seas and Greater North Sea sub-regions. BH2: Southern part of Greater North Sea |
Table 3. Summary of the UK environmental targets and associated indicators for intertidal habitats.
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UK Targets |
Indicators that have been used |
Spatial coverage |
|
Habitat condition, Physical damage, and Condition of the benthic community For intertidal rocky shores: At the scale of the Marine Strategy Framework Directive sub-regions, rock and biogenic reef habitats are not significantly affected by human activities: For all listed (special) and predominant habitat types the area of habitat in poor condition (as defined by condition indicators) must not exceed 5% of the baseline value (Favourable Reference Area for Habitats Directive habitats). For intertidal listed (special) sediment habitat types: |
|
Water Framework Directive: Intertidal areas. UK Charting Progress 2 Regional Seas which cover Celtic Seas and Greater North Sea sub-regions.
MarClim: Intertidal survey rock areas, UK level |
Progress since 2012
Soft Sediments and Rocky and biogenic habitats
In 2012, a consensus of experts concluded that the spatial extent of damage to the seabed from fishing gear was greater than any damage caused by other activities (HM Government, 2012). This current assessment uses new indicators, developed since 2012, to assess the damage caused by fishing to sediment habitats and to assess the condition of invertebrate communities living in those habitats.
Intertidal habitats
No indicators were used in 2012 assessments. Since then, new indicators have been developed based on existing Water Framework Directive tools and data from the long-term Marine Biodiversity and Climate Change (MarClim) monitoring programme.
Outstanding issues
Soft Sediments habitats
The wide-ranging and enduring impacts on soft sediments make it difficult to establish reference conditions against which habitats can be assessed. Data on invertebrate communities were collected mostly in inshore areas and were very sparse in offshore habitats. In contrast, data on pressure from fishing was mainly from offshore areas. Data from other activities were included at only a few sites
Rocky and biogenic habitats
There is limited data from surveys of biogenic and rocky habitats, so much of their extent and distribution had to be predicted from environmental modelling based on known locations of existing habitats. The mapping of pressures was incomplete because of the lack of data on inshore fisheries. Data on pressure from other activities were only included for the assessment of biogenic habitats.
Intertidal habitats
Assessments represent a small proportion of the overall UK coastline. Integration across indicators has not been possible at this stage due to the limited development of approaches to combine individual indicator results.
Achievement of targets and indicators used to assess progress
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Targets |
Indicator |
Assessment Results |
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Soft Sediments |
Sublittoral Rock and Biogenic Habitats |
Intertidal habitats |
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Habitat extent: Area of habitat is stable or increasing and is not smaller than the baseline value.
|
Physical loss of predicted habitat |
N/A |
The UK target has not been met in both Celtic Seas and Greater North Sea: physical loss of seabed habitat due to human activities in UK waters (up to 2016) has resulted in a reduction in the predicted area of seagrass beds and horse mussel reefs. |
N/A |
|
Habitat condition, Physical damage, and Condition of the benthic community: The level of exposure to pressure at the level of the Marine Strategy Framework Directive sub-regions should not result in more than 'Moderate Impact/Vulnerability' of the habitat’ (dependent on the sensitivity of the habitat to this pressure). |
OSPAR BH3: Extent of Physical damage indicator to predominant and special habitat |
The UK target was met in the in UK waters to the west of the Celtic Seas The UK target was not met in the Greater North Sea and Celtic Seas. |
The UK target has not been met in both the Celtic Seas and the Greater North Sea. The UK Target was met in UK waters west of the Celtic Seas. |
N/A |
|
Water Framework Directive Aggregated Rocky Shore Macroalgal Index |
N/A |
N/A |
The status of macroalgae communities on rocky shores appears to be consistent with Good Environmental Status in all assessed areas. All assessments are assigned low confidence due to sparse data coverage. |
|
|
Water Framework Directive Aggregated Saltmarsh Tool |
N/A |
N/A |
The status of saltmarsh communities appears to be consistent with Good Environmental Status in 2 assessed areas, with a further 2 assessments not being consistent with Good Environmental Status. All assessments are assigned low confidence due to sparse data coverage. |
|
|
Water Framework Directive Aggregated Intertidal Seagrass Tool |
N/A |
N/A |
Intertidal seagrass status appears to be consistent with Good Environmental Status in all assessed areas. All assessments are assigned low confidence due to sparse data coverage. |
|
|
MarClim Intertidal rock community change indicator
|
N/A |
N/A |
Some seas around the UK are warming more than others. In these areas, intertidal communities and, algae and other plants, are more affected by increases in sea surface temperature. This will make these communities less resilient to the effects of additional anthropogenic pressures on rocky shores. |
|
|
Habitat condition, Condition of the benthic community: The level of exposure to pressure at the level of the Marine Strategy Framework Directive sub-regions should not result in more than 'Moderate Impact/Vulnerability' of the habitat’ (dependent on the sensitivity of the habitat to this pressure). Within each Regional Sea, the percentage of macrobenthic invertebrate samples achieving the quality target of Environmental Quality Ratio ≥0.64 (Water Framework Directive and Good Environmental Status) is assessed against a quantity threshold of 15% as the maximum acceptable area below the quality target. |
OSPAR BH2: Benthic communities indicator |
The UK target was not assessed due to data limitations within the Marine Strategy Framework Directive sub-regions A pilot assessment in the Southern North Sea showed significant changes in the diversity of the benthic communities in relation to fishing pressure. Shallow coastal areas generally showed lower condition compared to deeper offshore areas. |
N/A |
N/A |
|
UK Water Framework Directive Aggregated Infaunal Quality Index |
The target could not be fully assessed at the sub-regional scale due to the limited data coverage offshore. But in those areas that were assessed, the target was met in 5 of the 8 UK Regional Seas. |
N/A |
N/A |
|
Further information
Seafloor Integrity: Sublittoral Rock & Biogenic habitats
Extent to which the target on habitat extent has been met
The UK target has not been met in both the Celtic Seas and the Greater North Sea: physical loss of seabed habitat due to human activities in UK waters (up to 2016) has resulted in a reduction in the predicted area of seagrass beds and horse mussel reefs.
Evidence to support the evaluation of habitat extent
The supporting evidence for this target evaluation and the extent that the criterion 1.5 in the Commission Decision 2010/447/EU (European Commission, 2010) have been achieved comes from the assessment of the Physical loss of predicted habitat indicator.
The results from the modelled calculations have shown that aquaculture navigational dredging, dredge/spoil disposal, coastal development and recreational activity are the main causes of physical loss to horse mussel reefs and seagrass beds. Pressure from these activities results in direct substratum loss, smothering by suspended sediment, and cause changes to the characteristics of the habitat. This assessment focuses on horse mussel reefs (Modiolus modiolus) and seagrass beds (Zostera marina). Both habitats are very fragile and vulnerable to pressures from human activities. Statistical modelling was used to estimate the potential distribution and extent of suitable habitat for horse mussel reefs and seagrass beds. The results show that 2% of the potential habitat for seagrass beds in the UK has been lost because of activities taking place up to 2016, equating to 32km2 of lost habitat. A larger area of horse mussel reefs, totaling 39km2, has been lost because of human activities but this represents only 0.5% of potential habitat for horse mussel in UK waters. The assessment results indicate that for both habitats the indicator target of ‘area is stable or increasing’ has not been achieved during this reporting period. This assessment is based on estimates of the extent of Potential Physical Loss to each habitat caused by human activities up to and including the period 2010 to 2016. Mathematical modelling was used to estimate the potential distribution and extent of suitable habitat for horse mussel reefs and seagrass beds. It is important to note that the predicted suitable habitat areas represent ‘potential’ habitat, which will differ from the actual ‘realised’ (occupied) habitat. The model could be improved if further data from realised habitat is included in future assessments.
Potential Physical Loss is likely to be underestimated because not all relevant activities were included in the assessment due to the lack of data.
Physical loss is a permanent change to the seabed that has lasted or is expected to last for 12 years or more. Although other pressures are known to impact on these habitats and are currently of greater concern, many are reversible (within 12 years) or damaging and as such were not in the scope of this analysis of physical loss (no recovery within 12 years). The estimation amount of damage caused before the irreversible loss is covered by the assessment of habitat condition, physical damage, and condition of the benthic community
Evaluation of the extent that the targets on habitat condition, physical damage and condition of the benthic community has been met
The UK target on levels of physical damage to predominant habitats has not been met in both the Celtic Seas and the Greater North Sea. The UK target was met in UK waters west of the Celtic Seas.
Evidence to support the above evaluation of habitat condition, physical damage and condition of the benthic community
The supporting evidence for this target evaluation and the extent that the criteria set out in the Commission Decision 2010/447/EU (European Commission, 2010) have been achieved comes from the assessment of the indicator on the extent of physical damage to predominant and special habitats.
This indicator assessment has been undertaken as part of the OSPAR Intermediate Assessment 2017 (OSPAR Commission, 2017a). As such, the indicator assessment was undertaken in each OSPAR Region (approximate to each Marine Strategy Framework Directive sub-region) using data from the UK and neighbouring countries.
The target is achieved in the UK waters west of the Celtic Seas (in OSPAR Region V – Wider Atlantic), although the disturbance in some areas around Rockall Bank and the shelf break was at the highest level due to a combination of sensitive habitats and regular fishing activity. Incomplete data meant it was not possible to assess fishing impacts in the UK portions of OSPAR Region IV (The Bay of Biscay (the Canyons)) and OSPAR Region I (Arctic Waters).
Rocky habitats showed a large variation in the degree of disturbance with areas within UK sub-regional seas experiencing higher disturbance whereas others have not experienced a disturbance at all. Moderate energy circalittoral rock seems to have the highest proportions disturbance, particularly in the UK waters west of the Celtic Seas, the Northern North Sea, and the English Channel.
Sediment habitats
Evaluation of the extent that the targets on habitat condition, physical damage and condition of the benthic community has been met
The UK target covering physical damage of predominant habitats was met in the in UK waters to the west of the Celtic Seas. The UK target was not met for predominant habitats in the Greater North Sea and Celtic Seas.
A pilot assessment in the Southern North Sea showed significant changes in the diversity of the benthic communities in relation to fishing pressure. Shallow coastal areas generally showed lower condition compared to deeper offshore areas.
The condition of some macrobenthic invertebrate communities could not be fully assessed at the sub-regional scale due to the limited data coverage offshore. In those areas that were assessed, the target was met in 5 of the 8 UK Regional Seas.
Evidence to support the above evaluation of habitat condition, physical damage and condition of the benthic community
The supporting evidence for this target evaluation and the extent that the criteria in the Commission Decision 2010/447/EU (European Commission, 2010) have been achieved comes from the assessment of three indicators:
- Extent of Physical Damage to Predominant Seafloor Habitats - UK
- UK Water Framework Directive Aggregated Infaunal Quality Index
- Condition of Benthic Habitat Communities: Assessment of Coastal Habitats in Relation to Nutrient and Organic Enrichment.
A large-scale model-based approach is used for the Extent of Physical Damage to Predominant Seafloor Habitats indicator, which assesses the intensity and distribution of disturbance across a sub-region. Multimeric indices are used within the other two indicators, which are quantitative condition-based indictors, and assess the impact at a specific location.
Extent of Physical Damage to Predominant Seafloor Habitats - UK
This indicator was previously named: Impact/Vulnerability of Habitat to Abrasion (physical pressure).
The target is achieved in the UK Atlantic waters beyond the western boundary of the Celtic seas, although there were high levels of disturbance in some areas around Rockall Bank due to a combination of sensitive habitats and regular fishing activity. Incomplete data meant that it was not possible to assess fishing impacts in the UK waters within the northern parts of the Bay of Biscay sub-region and on the southern edge of the OSPAR Arctic waters.
The most widespread habitat types in the UK, are sublittoral soft sediments that include sublittoral coarse sediment, sand, mud, and mixed sediment and were used to examine spatial variability. Some areas assessed (Southern Celtic Seas and the English Channel) showed higher levels of disturbance across all habitat types (more than 50% of habitat area subject to higher disturbance), while other areas showed more variation in disturbance levels.
Aggregated Infaunal Quality Index
The overall indicator target may not have been achieved for the Greater North Sea Marine Strategy Framework Directive sub-region, with a considerable proportion of its assessed area failing to meet the indicator quality target. However, there are differences within the UK Regional Seas. The target is met in the Northern North Sea and Eastern English Channel regions but it was not met in the Southern North Sea, where the surface area failing to meet the target occurs at such an extent as to result in the Marine Strategy Framework Directive sub-region not meeting the overall target.
The overall target has largely been achieved within the Celtic Seas Marine Strategy Framework Directive sub-region, with the majority of its assessed area meeting the quality target. The quality threshold target was met for 85% or more of the assessed criteria within the Regional Seas of the Minches and Western Scotland, Scottish Continental Shelf, and shared waters between Northern Ireland and the Republic of Ireland. The target was not met for the Western Channel & Celtic Seas and the Irish Sea Regional Seas, which fall within the Celtic Seas sub-region. The target has not been assessed in the rest of the Celtic Seas due to lack of data in the Regional Seas Atlantic North-West Approaches, Rockall Trough and Faeroe/Shetland Channel.
Low confidence has been assigned to all assessments, primarily due to the low number of data points available for the Water Framework Directive assessments.
Condition of benthic habitat communities
This indicator assessment has been undertaken as part of the OSPAR Intermediate Assessment (OSPAR Commission, 2017b). As such, the indicator assessment was undertaken in each OSPAR Region (approximate to each Marine Strategy Framework Directive sub-region) using data from the UK and neighbouring countries.
Most marine species rely directly or indirectly on the seafloor to feed, hide, rest or reproduce. In most cases, benthic habitats contain communities with no or slow mobility, which are exposed when a bottom pressure occurs because they cannot flee or escape. As a result, the condition of benthic habitat communities provides an important signal of the state of the marine environment. Benthic diversity indices are used to assess the impacts of different pressures, such as disturbance of the seabed and extraction of species by fisheries, nutrient and organic enrichment, sedimentation (such as from the dumping of dredged material or extraction of aggregates) and contaminants, on the benthic habitat and community condition.
For all assessment areas, the diversity value showed significant changes in relation to fishing pressures. It should be noted that data transformation was required due to the wide variations in the sources of data available. Furthermore, there are significant gaps in the availability of suitable data for this analysis in UK waters. Several UK areas showed a relatively high benthic condition, although the results have a low confidence as reference conditions for those offshore areas were mainly based on similar habitat types from the Netherlands, and therefore they will need to be refined. However, a full quantitative assessment of the Marine Strategy Framework Directive sub-regions was not possible at this stage due to data limitations and early stages of indicator development.
Intertidal habitats
Evaluation of the extent that the targets on habitat condition, physical damage, and condition of the benthic community has been met
The assessment of community response to changes in temperature, the Marine Biodiversity and Climate Change (MarClim) Indicator, shows that some seas around the UK are warming more than others. In these areas, intertidal communities and in particular, algae and other plants, are more affected by increases in sea surface temperature. This will make these communities less resilient to the effects of additional anthropogenic pressures on rocky shores.
The targets covering the proportion of surveyed rocky shore macroalgae communities at an acceptable condition has been achieved in the Celtic Seas and Greater North Sea Marine Strategy Framework Directive sub-regions. For this indicator, a threshold of 15% was used in order to align the method with the thresholds used in the Water Framework Directive. The status of macroalgae communities on rocky shores appears to be consistent with Good Environmental Status in all assessed areas. All assessments are assigned a low confidence due to sparse data coverage.
The targets covering the area of intertidal saltmarsh communities at an acceptable condition have largely been achieved in the Celtic Seas Marine Strategy Framework Directive sub-region but has not been met for the Greater North Sea. The status of saltmarsh communities appears to be consistent with Good Environmental Status in 2 assessed areas, with a further 2 assessments not being consistent with Good Environmental Status. All assessments are assigned a low confidence due to sparse data coverage.
The targets covering the condition of intertidal seagrass communities have been achieved in the Celtic Seas and Greater North Sea Marine Strategy Framework Directive sub-regions. Intertidal seagrass status appears to be consistent with Good Environmental Status in all assessed areas. All assessments are assigned a low confidence due to sparse data coverage.
Evidence to support the evaluation of habitat condition, physical damage and condition of the benthic community
The supporting evidence for this target evaluation and the extent that criteria 1.6, 6.1, and 6.2 in the Commission Decision 2010/447/EU (European Commission, 2010) have been achieved comes from the assessment of 4 indicators:
- Marine Biodiversity and Climate Change (MarClim) Intertidal Rock Community Change Indicator
- UK Water Framework Directive Aggregated Intertidal Rocky Shore Macroalgal Index
- UK Water Framework Directive Aggregated Intertidal Saltmarsh Tool
- UK Water Framework Directive Aggregated Intertidal Seagrass Tool
These indicators are designed to assess different habitat types within intertidal areas.
Marine Biodiversity and Climate Change (MarClim) Intertidal Rock Community Change Indicator
The Community Temperature Index has been developed as a practical measure of community response to changes in temperature along geographical gradients and over time. Patterns of Community Temperature Index for animals and plants follow gradients of sea surface temperature, with Community Temperature Index for animals changing more rapidly with temperature than that for plants. Communities of animals on rocky shores are comprised of species with distributions centred in warmer areas, while plant communities are generally comprised of cold-water species, therefore making a negative response to climate change more likely for plants. The negative thermal bias of macroalgae across most of the UK (except for eastern Scotland and north-east England) may indicate communities are more vulnerable to the effects of warming as most species are in the cold half of their range and therefore likely to decline with further warming. Communities of intertidal animals have positive thermal bias across the region, with only local patches of modestly negative thermal bias. Areas of locally negative thermal bias suggest areas where species of animals from warmer climates may be likely to invade.
Aggregated Intertidal Rocky Shore Macroalgal Index
The survey data available for the assessments show that the quantity threshold has been met for both Marine Strategy Framework Directive sub-regions and all constituent UK Regional Seas.
In the Northern North Sea, Eastern English Channel, Minches and Western Scotland, Scottish Continental Shelf and shared waters between Northern Ireland and the Republic of Ireland, the quality threshold is met for all contributing water bodies. For the Western Channel & Celtic Seas and Irish Sea, the proportion of surveys meeting the quality threshold remains above the quantity threshold of 85% although there are instances of surveys failing to meet the quality threshold. Two Regional Seas have not been assessed due to either the absence of data or the presence of the habitat required for the indicator.
Low confidence has been assigned to all assessments, primarily due to low spatial coverage of the Water Framework Directive assessments and low coverage of water bodies categorised as being ‘At Risk’ or ‘Probably At Risk’ from point source pollution sources within the Water Framework Directive Risk Assessments. Agreement between the rocky shore macroalgae assessment results and risk assessment results is low, potentially indicating either a low correlation between the indicator to point source pollution pressures (either due to variability in the indicator or the criteria used for the risk assessments) or a discrepancy between the threshold required to trigger a water body being categorised as ‘At Risk’ or ‘Probably At Risk’ and the indicator quality target threshold.
Aggregated Intertidal Saltmarsh Tool
The overall indicator target has not been achieved for the Greater North Sea Marine Strategy Framework Directive sub-region, with a considerable proportion of its assessed area failing to meet the indicator quality target. While the indicator quality threshold has been met for all contributing water bodies in the Northern North Sea, the results indicate that a sufficient area of the Southern North Sea and Eastern English Channel Regional Seas are below the quality extent threshold to result in the likely failure of the Marine Strategy Framework Directive sub-region. In the Southern North Sea and Eastern English Channel Regional Seas, the majority of water bodies assessed as below the quality target are within water bodies categorised as a ‘Heavily Modified Water Body’ for morphological alteration pressures. Of these, only a single Water Framework Directive water body in the Southern North Sea (Blackwater Outer) has sufficient mitigation measures in place to meet the target of ‘Good Ecological Potential’. The ecological potential of a water body represents the degree to which the quality of the water body’s aquatic ecosystem approaches the maximum it could achieve, given the heavily modified and artificial characteristics of the water body that are necessary for the use or for the protection of the wider environment.
The overall target has largely been achieved within the Celtic Seas Marine Strategy Framework Directive sub-region, with the majority of its assessed area within the Western Channel and Celtic Sea Regional Sea meeting the quality target. Five Regional Seas have not been assessed due to either an absence of intertidal habitat or an absence of Water Framework Directive classification data.
The confidence for Water Framework Directive Saltmarsh Indicator assessments has been categorised as low for all Regional Seas, primarily due to the low spatial coverage of the Water Framework Directive assessments.
Aggregated Intertidal Seagrass Tool
The survey data available for the assessments show that the overall target has been met for both Marine Strategy Framework Directive sub-regions and all constituent Regional Seas, with the quality threshold having been met for the majority of the contributing water bodies. This indicates that the activities which might cause impact to intertidal seagrass communities may be operating at a level which is not causing a deleterious effect. Four Regional Seas have not been assessed due to either an absence of intertidal habitat which is required by the indicator within Water Framework Directive coastal water bodies or an absence of existing Water Framework Directive classification data. The natural conditions required for seagrass beds to exist limits their occurrence in coastal water bodies.
The confidence for Water Framework Directive Intertidal Seagrass Indicator assessments has been categorised as low for all assessments, primarily due to low spatial coverage of the Water Framework Directive assessment results.
Moving forward
Additional data from existing Marine Protected Areas will be included in future assessments. We will develop assessment methods further in order to integrate assessment results and help to evaluate the effects of human activities in relation to climate change. We will develop indicators to assess the status of sublittoral rock, biogenic reefs and typical species.
Further information
Several knowledge gaps were identified in the individual indicator assessments that will need to be addressed in the most appropriate forum (such as through the UK Marine Monitoring and Assessment Strategy community and OSPAR). Most of these gaps are common themes across indicators and addressing those could help to strengthen the confidence and quality of assessments as well as the geographical coverage of assessment results. The knowledge gaps are described briefly below.
- The incorporation of reference values and empirical/quantitative condition indicators applicable at the sub-regional scale will help to improve confidence on the assessments and inform the effectiveness of management measures. This will help not only to validate the outputs from models but also to have statistically robust values against which targets can be assessed.
- There is a lack of high-resolution inshore fisheries data which is likely causing underestimation of some of the modelled indicator results (such as physical loss and physical damage indicators). This could be improved by working closely with the fishing industry exploring alternative data avenues, such as the Automatic Identification System.
- Improved collation and standardisation of human activity data from non-fisheries activities which could then be transformed into pressure data. Having more accurate data will help us to understand the spatial and temporal cumulative effects from other pressures apart from fisheries.
- Validate and calibrate the results produced by modelled indicators, such as the physical damage indicator, using newly available data from monitoring programmes. Improved direct monitoring data collection through survey design, spatial coverage, and inferential power would enable data to feed more easily into indicator assessments.
- Explore the effects of non-native species in the benthic assessments and how they could be considered within indicators.
- Exploring more efficient ways to incorporate the Habitat Directive (European Council, 1992) and national assessments within Marine Strategy Framework Directive assessments will improve the accuracy and confidence in indicator results and integrated assessments of Good Environmental Status.
- Additional data from Marine Protected Areas should be included in future assessments.
- Development of integration methods to evaluate the effects of climate change in relation to human activities would help to assess cumulative effects.
References
Acknowledgements
HM Government (2012) ‘Marine Strategy Part One: UK Initial Assessment and Good Environmental Status’ (viewed on 5 July 2018)
HM Government (2015) ‘Marine Strategy Part Three: UK Programme of Measures’ December 2015 (viewed on 5 July 2018)
European Council (1992) ‘Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora’ Official Journal of the European Union L 206, 22.7.1992, pages 7-50 (viewed 1 October 2018)
European Commission (2010) ‘2010/477/EU: Commission Decision of 1 September 2010 on criteria and methodological standards on good environmental status of marine waters (notified under document C(2010) 5956)’ Text with EEA relevance, Official Journal of the European Union L 323 2.9.2010, pages 14-24 (viewed on 22 November 2018)
OSPAR Commission (2017a) ‘Intermediate Assessment 2017: Extent of Physical Damage to Predominant and Special Habitats’ (viewed on 16 January 2019)
OSPAR Commission (2017b) ‘Intermediate Assessment 2017: Condition of Benthic Habitat Communities: Subtidal Habitats of the Southern North Sea’ (viewed on 16 January 2019)