Wyville-Thomson Ridge MPA


Status: Candidate Special Area of Conservation and Site of Community Importance (cSAC/SCI)
Click to link to the interactive map


The Wyville-Thomson Ridge is a rocky plateau situated in the Atlantic Ocean to the north-eastern part of the Rockall Trough.


The Wyville-Thomson Ridge is composed of extensive areas of stony reef interspersed with gravel areas and bedrock reef along its flanks, and supports diverse biological communities representative of hard substratum in deep water including a range of sponges; stylasterid, cup and soft corals; brachiopods; bryozoans; dense beds of featherstars and brittlestars; sea urchins, sea cucumbers and sea spiders. The stony reef is thought to have been formed by the ploughing movement of icebergs through the seabed at the end of the last ice age.

More detailed site information can be found on the Summary tab below


Map displaying the MPA boundary

View and download spatial data for this MPA

on the JNCC UK MPA interactive map.


Legislation behind the designation: EU Habitats Directive 1992 transposed into UK law by the Offshore Marine Conservation (Natural Habitats &c.) Regulations 2007 (as amended)


Protected Features:

Features Feature Type Conservation Objectives

        1170 Reefs        

        Annex I Habitat        

Restore to Favourable Condition


Conservation Objectives
The overarching conservation objectives for the designated features of all protected sites in UK offshore waters is to ensure they either remain in, or reach favourable condition. The ability of a designated feature to remain in, or reach favourable condition can be affected by its sensitivity to pressures associated with activities taking place within or in close proximity to a protected site.

Specific information on the conservation objectives relating to this cSAC/SCI is provided in the Conservation Advice tab.

Site Timeline

The diagram below is a summary of the key milestones involved in the selection and designation of Wyville-Thomson Ridge cSAC/SCI.  More detail can be found within the relevant documentation listed below.

Wyville-Thomson Ridge designation timeline

Relevant documentation

The documents referred to below and any other historical documents relating to the Wyville-Thomson Ridge cSAC/SCI were produced during the selection and designation process and therefore may be out of date.  This Site Information Centre is the most up to date source of information for this MPA, and will reflect any additional information gathered since these documents were produced.


Information about the SAC site selection process is available on the JNCC SAC pages.



Site overview
The Wyville-Thomson Ridge is located on the Scottish continental shelf edge approximately 150km north west of Cape Wrath, and extends in a north westerly direction towards the Faeroe Bank. The Ridge divides the relatively warmer waters of the Rockall Trough from the relatively cooler waters of the Faroe-Shetland Channel, and is a transitional area between the two water masses.

The Wyville-Thomson Ridge is approximately 20km wide and 70km long and rises from over 1000m depth to less than 400m at the summit. The ridge is composed of extensive areas of stony reef interspersed with gravel areas and bedrock reef along its flanks. The stony reef is thought to have been formed by the ploughing movement of icebergs through the seabed at the end of the last ice age. These iceberg ‘ploughmarks’ consist of ridges of boulders, cobbles and gravel where finer sediments have been winnowed away by high energy currents at the site, interspersed with finer sediment troughs up to 10m deep.

The rock and stony reef areas in the site support diverse biological communities representative of hard substratum in deep water, including a range of sponges; stylasterid, cup and soft corals; brachiopods; bryozoans; dense beds of featherstars and brittlestars; sea urchins, sea cucumbers and sea spiders. Communities on the bedrock reef vary in species composition between the two sides of the ridge due to the influences of different water masses. This combination of water masses in one area is unique in UK waters.

Further detail on the evidence for this cSAC/SCI can be found on the Evidence tab.


Site location:  Coordinates for this cSAC/SCI can be found in the Natura 2000 Standard Data Form listed in the Relevant Documentation.

Site area:  This site has an area of 1,740km2, slightly larger than the neighbouring Shetland Isles.

Site depth range: The site is on a ridge at the edge of the continental shelf, sitting at 310m, sloping down to its deepest at 1010m below sea level.

Charting Progress 2 Biogeographic Region: The MPA spans the boundary between the Atlantic North-West Approaches, Rockall Trough and Faeroe/Shetland Channel region and the Scottish Continental Shelf region

Site boundary description
The boundary for the Wyville-Thomson Ridge cSAC/SCI is a simple polygon defined by whole degrees and minutes, fully enclosing the minimum area necessary to ensure protection of the Annex I reef of the site. Bottom trawling is a threat to the reef and, therefore, the proposed boundary includes a margin to allow for mobile gear on the seabed being at some distance from the location of a vessel at the sea surface.


The information for this site summary was adapted from documents listed in the Relevant Documentation section and incorporates any further information gathered since these documents were produced.


Site specific data
There is a range of data that underpin this cSAC/SCI. The full overview of the data used to support site identification, along with information on confidence in feature presence and extent is available in the Wyville-Thomson Ridge SAC Selection Assessment Document

JNCC will be adding relevant survey data for this MPA to the Interactive MPA Mapper in due course.

Some of the data for this cSAC/SCI has been collected through JNCC funded or collaborative surveys and some through other means. Data from these surveys provide direct evidence confirming the presence of the protected features within the site.


Survey and data gathering

  • Wyville-Thomson Ridge and Faroe-Shetland Channel proposed MPA Survey – 2012
    This survey was a collaboration between JNCC and Marine Scotland Science. Video and camera imagery were collected to support evidence on the presence and extent of the Annex I reef feature of the Wyville-Thomson Ridge.
  • Strategic Environmental Assessment (SEA) Survey 7 - 2006
    This survey was commissioned by the Department for Trade and Industry (now Department for Energy and Climate Change (DECC))  as part of the Strategic Environmental Assessment (SEA) survey programme. This survey aboard the commercial research vessel Franklin, in which JNCC collaborated, collected acoustic and underwater imagery data from areas off the north and west coasts of Scotland including the Wyville-Thomson Ridge.
  • Atlantic Frontier Environmental Network (AFEN) - 1996 - 2000
    Southampton’s National Oceanography Centre (NOC) undertook large-scale sampling of the shelf edge and slope west of Shetland on behalf of the Department for Transport and Industry (now the Department for Energy and Climate Change – DECC) on a series of surveys undertaken between 1996 and 2000. These surveys, in which JNCC collaborated, helped characterise the geology, geomorphology and fauna on the Wyville-Thomson Ridge.
  • Towed Ocean Bottom Instrument (TOBI) surveys of the continental slope west of Shetland – 1996 & 1998.
    The National Oceanographic Centre (NOC) used sidescan sonar amongst other sampling methods to undertake a baseline environmental survey of the seafloor on the continental slope west of Shetland. This included the collection of extensive sidescan sonar data at the Wyville-Thomson Ridge.


Data analysis reports
Further analysis of data gathered as part of the surveys listed above are available via the following reports:

References for further supporting scientific literature consulted during the identification of this site can be found in the Wyville -Thomson Ridge SAC Selection Assessment Document.


Knowledge gaps
If you are aware of any additional information not referred to in any of the Relevant Documentation listed on the main page, please contact JNCC.



MPA Conservation Advice

Conservation objectives set out the desired state for the protected features of an MPA. The conservation objectives for the protected feature of the Wyville-Thomson Ridge cSAC/SCI has been set based on knowledge of the condition of the protected feature at the time of writing. Further information on feature condition and conservation objectives is provided in the Wyville-Thomson Ridge cSAC/SCI Conservation Objectives and Advice on Operations document.

This information is useful if you are:

  • preparing Habitats Regulations Assessments (HRAs) of proposed plans or projects that may affect the site;
  • planning measures to maintain or restore the site and its qualifying features;
  • monitoring the condition of the qualifying features; or
  • developing, proposing or assessing an activity, plan or project that may affect the site


The Conservation Objective for the protected feature at the MPA is:
Subject to natural change, restore the Annex I reef features back to favourable condition, such that:

  • The natural environmental quality is restored;
  • The natural environmental processes are maintained;
  • The extent, physical structure, diversity, community structure and typical species representative of stony and bedrock reef in the Atlantic North-West Approaches, Rockall Trough and Faroe-Shetland Channel Regional Sea Region and Scottish Continental Shelf Region are restored.

JNCC is working to provide more detailed advice on the relatively broad, high level conservation objective listed above. This supplementary advice will be posted here as and when it becomes available.


Advice on operations
In line with Regulation (18) of the Offshore Marine Conservation (Natural Habitats, & c.) Regulations 2007 (as amended) which apply to the UK’s offshore marine area. The advice on operations for the protected feature of Wyville-Thomson Ridge cSAC/SCI outline current knowledge of the nature and extent of activities taking place which may have a significant impact on the feature for which a site has been selected.

The advice on operations is based on JNCC’s scientific knowledge of the biological communities present at the time of writing and their sensitivities to pressures. For the most up-to-date information about the biological communities present within the site and their spatial distribution, please see the Evidence tab. Sensitivity information for biological communities identified within the site can also be found on MarLIN’s website.

JNCC also provides a list of activities occurring within the site and information on activity management is in the Activities and Management tab. This information is also useful when assessing an activity, plan or project which may affect the protected features and JNCC has provided this to aid the cumulative assessment of impacts of human activities within the site. While every attempt has been made to ensure this information is accurate and kept up-to-date, the list is not to be considered exhaustive or definitive. The list does not, for example, include activities occurring off-site which may also be capable of affecting the protected features.

The information contained within the advice on operations, Activities and Management tab, Evidence tab and MarLIN’s sensitivity assessments are useful if you are:

  • Carrying out any activity that may impact the site and need to find out how to operate within the law
  • an authority providing advice on specific proposals
  • an authority responsible for putting management measures in place

Our scientific understanding of the ecology of the site, its integrity and its qualifying features and how activities can affect them may change over time. JNCC’s conservation advice will be kept under review and will be periodically updated to reflect this and surveillance required under Article 17 of the Habitats Directive. Further information on JNCC's conservation advice is available via our offshore MPA conservation advice webpage.



Activities known to be currently occurring within this MPA
(Activities information correct as of April 2015)


Licensed activities:

  • Oil and gas – There are 28th Round DECC licensing blocks that overlap with the site and so there is a possibility that the area may be subject to oil and gas developments in the future.

Existing licensed activities that take place or may take place in the future within Wyville Thomson Ridge cSAC/SCI will continue to be managed in line with relevant legislation and application processes by the competent authorities. Information on JNCC's role in the provision of advice for licensed activities in the UK offshore area is available on the offshore industries advice webpages.


Activity is dominated by non-UK vessels, but demersal towed gears and static gears are used across the site both by UK and non-UK fleets. 

There is currently no fisheries management in place designed specifically to protect the designated features of this site.

Marine Scotland is leading discussions regarding the development of management for sites on a regional basis. A workshop involving national and international stakeholders was held for the north and west of Scotland sites in April 2014. The workshop was attended by fishermen and industry representatives from the UK and France and environmental NGOs. JNCC have provided a Fisheries Options Paper for the Wyville-Thomson Ridge cSAC/SCI to support these discussions. Following engagement with stakeholders, Marine Scotland will draw up management proposals to submit to the European Commission.

Where they are required, the Scottish Government is aiming for fisheries management measures for Wyville-Thomson Ridge cSAC/SCI to be in place by 2016. The site falls outside the UK’s 12 nautical mile limit and is to be exclusively managed under the EU Common Fisheries Policy. In accordance with Article 18 of the revised CFP, requests for management will be developed jointly between the UK Government and any Member States with a direct management interest in the area affected. Once drafted, there is a requirement to consult the relevant Advisory Council (North Western Waters AC) prior to submission of any final recommendations to the European Commission. Marine Scotland will be the lead authority regarding implementation and compliance of any measures.

Other activities:

  • Cables - Two telecommunications cables intersect the site.
    Cables are largely an unregulated activity in offshore waters depending upon the type of cable being laid (or maintained), where it is being laid between and whether the cable is part of a larger development (which may be regulated). Any cable not directly associated with an energy installation does not require a marine licence beyond 12 nautical miles. JNCC encourages early discussion from operators regarding any plans related to new or existing cables, and encourages the undertaking of non-statutory Environmental Impact Assessments for new or existing cable projects to assess their effect on the protected features of the MPA.
  • Shipping - One Royal Yachting Association cruise route crosses the site and the site maybe traversed by other ships.
    Under international law, ships have a rite of passage at sea including in areas designated as MPAs (unless management specifies the restriction of ship transiting as outlined through an International Maritime Organisation measure). The pressures associated with shipping activity within Wyville-Thomson Ridge cSAC/SCI are not considered likely to impact the protected features of the site.


Site Management

Management Plan: JNCC is undertaking a review of management plan requirements for offshore MPAs. Further detail will be provided at a later date.
For information on management actions being taken forward for this site, please go to Marine Scotland's fisheries Management in Offshore SACs webpage.
Management Group: None at present


Further information on activities and feature sensitivity to these pressures can be found under the Conservation Advice tab.




MPA Monitoring

JNCC is currently leading on the development of a strategy for biodiversity monitoring across all UK waters, to include MPA monitoring. For MPAs, data and evidence collected from monitoring activities will aim to:

  • Enable assessment of condition of the features within sites;
  • Enable assessment of the degree to which management measures are effective in achieving the conservation objectives for the protected features;
  • Support the identification of priorities for future protection and/or management; and,
  • Enable Government to fulfil its national and international assessment and reporting commitments in relation to MPAs and help identify where further action may be required.


Information on monitoring of this MPA will be provided when it becomes available.



MPA Assessment

Assessments of the condition of designated features in offshore MPAs are required to report against our legal obligations. Ideally these assessments should be based on observed data, and then measured against targets for predefined indicators. However, for MPAs in offshore waters we do not always have the appropriate information to be able to do so. This is particularly true for seabed habitats, which are the main type of feature designated for protection in offshore MPAs. 

To address these challenges, JNCC has been an active partner in the development of new approaches and tools for the assessment of habitats and species for a variety of national and international status reports. They include the second cycle of the Conservation Status Assessment reports under the EU Habitats Directive, Charting Progress 2 (CP2) and the OSPAR Quality Status Report (QSR). JNCC continues to develop and pilot tools for the assessment of marine habitats and species in offshore waters to improve the quality and transparency of our offshore MPA assessments, and contribute to the monitoring of marine biodiversity in UK waters. These tools cover methods for producing interim assessments of site features and their responses to pressures, as well as developing more robust indicators for determining condition of the features.

Every six years, Member States are required under Article 17 of the EU Habitats Directive to report on the Conservation Status of Annex I habitats and Annex II species on the Habitats Directive.  The assessments should consider the habitat or species both within the Natura 2000 network and in the wider sea.  The latest report was submitted by the UK in 2013 and provided a second assessment of the conservation status of relevant habitats and species within UK marine waters during 2007-2012. The next report is for the period 2013-2018 and is due in 2019; information on the condition of features within SACs will make a contribution to this report. 

The assessments of features within MPAs will also feed into six yearly reports on the state of the marine environment under the Marine Strategy Framework Directive (MSFD), which aims to achieve Good Environmental Status (GES) by 2020.




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