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Hatton-Rockall Basin MPA

Status: Nature Conservation Marine Protected Area (Nature Conservation MPA)

Situated in a deep-water basin to the far west of Scotland, the Hatton-Rockall Basin MPA supports a range of species adapted to life in deep waters.


The Hatton-Rockall Basin MPA is situated in a deep-water basin to the far west of Scotland. Water depth at the site is over 1 km and the muddy sediments present support a range of species adapted to life at this depth.

The site is designated to protect unusual aggregations of deep-sea sponges, an OSPAR Threatened and/or Declining habitat. The MPA also includes protection for offshore deep-sea muds and a series of unique geological features known as polygonal faults. Polygonal faults are cracks in the seafloor, similar in appearance to those on a sun scorched desert. More detailed site information can be found in the Summary section below.

Map displaying the Hatton-Rockall Basin MPA boundary and associated protected feature data. Visit JNCC's MPA Mapper to further view and explore data for this MPA.

Map showing Hatton-Rockall Basin Marine Protected Area and linking to the MPA mapper


Legislation behind the designation: Marine and Coastal Access Act (2009)


Protected Features

Feature Feature Type
Deep-sea sponge aggregations Habitat
Offshore deep sea muds Habitat
Sediment drifts and polygonal faults representative of Hatton Bank (and adjacent sea floor) Key Geodiversity Area. Geomorphological

Specific information on the conservation objectives relating to this site is provided in the Conservation Advice section.

The acquisition of new data may result in updates to our knowledge on feature presence and extent within this site. The most up-to-date information is reflected on the map on this page and in JNCC’s MPA mapper and the evidence underpinning this can be viewed in the Monitoring and Evidence section.


Site Timeline

The diagram below is a summary of the key milestones involved in the selection and designation of Hatton-Rockall Basin MPA. More detail can be found in the Relevant Documentation section below.

November 2012
Site recommended to Marine Directorate.
Summer 2013
Site subject to formal public consultation.
July 2014
Site designated by Marine Directorate as a Nature Conservation MPA.


Relevant Documentation

The documents referred to below and any other historical documents relating to Hatton-Rockall Basin were produced during the selection and designation process and therefore may be out of date.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 Nature Conservation MPA site selection process is available on the JNCC's Nature Conservation MPA webpages.

These resources are available on JNCC's Resource Hub.



Last updated: October 2017

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 overview

The Hatton-Rockall Basin MPA is situated in a deep-water basin to the far west of Scotland. The site is located between Hatton Bank to the west and Rockall Bank to the east and water depth at the site is over 1 km. The site is designated to protect unusual aggregations of deep-sea sponges, an OSPAR Threatened and/or Declining habitat. Two different types of deep-sea sponge aggregations are known to be present; aggregations dominated by encrusting sponges and bird’s nest sponge (Pheronema carpenteri) fields. The bird’s nest sponge fields within the site are the only known examples to occur in UK waters. The encrusting sponge aggregation is typified by encrusting grey sponges living on boulders and mud substrata. Both types of deep-sea sponge aggregations act as biodiversity hotspots, with a range of other species associated with them. For the bird’s nest sponge fields, these include ascidians, formaniferans, polychaetes and burrowing anemones, while the encrusting sponge aggregations include anemones, ascidians, crinoids and ophiuroids. The seabed in the area is littered with spicules, spiny remnants of dead sponges, that inhibit the establishment of burrowing animals but allow surface-dwelling species to thrive. For example, beds of brittlestars are present, which live on the surface of the seabed, filtering food from passing currents.

Offshore deep sea mud habitat is predicted to be present throughout the Hatton-Rockall Basin MPA and is another of the site’s protected features. It is predicted that there are two different types of offshore deep-sea mud habitat in the MPA. The majority of it is believed to be "Atlantic mid bathyal mud and sandy mud", but this encompasses a patch of "Atlantic upper bathyal mud and sandy mud". There is little information on the level of biological diversity and composition of communities supported by the offshore deep-sea mud habitats in the MPA, however limited survey data support the presence of habitat that is dominated by different species of burrowing anemone as well as echinoderms such as starfish, sea cucumbers and sea urchins.

A series of unique geological features known as polygonal faults are also included for protection within the site. Polygonal faults are cracks in the seafloor, similar in appearance to those on a sun scorched desert. Usually polygonal faulting occurs below the seafloor, but the faults in the Hatton-Rockall Basin are present on the surface of the seabed, making this a unique example of the feature. The hard edges of these cracks may facilitate the aggregations of deep-sea sponges by providing a suitable surface for settlement. Along with the polygonal faults, sediment drifts are also protected within the Hatton-Rockall Basin MPA, as it is a representative feature of the Hatton Bank (and adjacent sea floor) Key Geodiversity Area.

Site location: Co-ordinates for this Nature Conservation MPA can be found in the Designation Order listed in the Relevant Documentation section.

Site area: 1,256 km2which makes it larger than the county of Moray at 1,233 km2.

Site depth range: The depth of the MPA ranges from 1,080 m below sea-level to a maximum of 1,200 m below sea-level.

Charting Progress 2 Biogeographic Region: Atlantic North-West Approaches, Rockall Trough and Faroe-Shetland Channel.

Site boundary description: The site is a simple polygon drawn to include all verified records of deep-sea sponges within the entire Hatton-Rockall Basin. The boundary has also been drawn to incorporate significant areas of both types of offshore deep-sea muds present in the region.


Monitoring and Evidence

Last updated: November 2023

The full overview of the various data used to support site identification along with information on confidence in feature presence and extent is available in the Hatton-Rockall Basin MPA Data Confidence Assessment. JNCC will be adding relevant survey data for this MPA to its MPA Mapper in due course. Some of the data for this MPA have 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

  • Survey of Darwin Mounds and North West Rockall (2011) – The cruise was part of the MAREMAP initiative (UK Marine Environmental Mapping Programme) and was a collaboration of multiple organisations including JNCC, Plymouth University and the National Oceanography Centre. The main aim of the survey was to use acoustic and imagery data to perform benthic habitat mapping in relation to human activity. The survey identified bird’s nest sponge aggregations, encrusting sponge aggregations and offshore deep-sea mud habitats.
  • 2006 Strategic Environmental Assessment (SEA), JNCC RV Franklin Survey (2006) – The Strategic Environmental Assessment (SEA) surveys were commissioned by the Department of Trade and Industry (now Department for Energy and Climate Change (DECC)). These surveys, in which JNCC collaborated, collected multibeam and underwater imagery data from areas off the north and west coasts of Scotland. In 2006, the survey visited the polygonal faults in the site and recorded deep-sea sponge aggregations and mud habitats.


Data analysis reports

Analyses of data gathered as part of the surveys listed above, as well as other relevant data analysis products, are available via the following reports:

  • EUSeaMap – Provides supporting information on the presence and extent of sedimentary features from a predictive seabed habitat map of European waters.
  • Application of the OSPAR definition of deep-sea sponge aggregations (2014) – JNCC commissioned a contract to apply the OSPAR definition of deep-sea sponge aggregations to verify suspected records of the habitat in UK waters. Survey data from this site was included in that contract and supported with high confidence the presence of Pheronema carpentari fields and encrusting sponge dominated aggregation types of deep-sea sponge aggregations
  • Analysis of biological data from the JC60 survey (2014) – The data from the National Oceanography Centre, University of Plymouth and JNCC survey of Darwin Mounds and North West Rockall, were analysed and help support the presence of offshore deep-sea muds and deep-sea sponge aggregations in Hatton-Rockall Basin MPA.
  • Report of the identification of Key Geodiversity Areas in Scotland's seas (2013) – This report helped support information on the presence and extent of important geological/geomphological areas in Scotland’s seas, which includes The Hatton Bank (and adjacent sea floor) Key Geodiversity Area of relevance to this NCMPA.


Additional relevant literature

References for further supporting scientific literature consulted during the identification of this site can be found in the Hatton-Rockall Basin MPA Data Confidence Assessment. Please be aware that although these sources contain information which is of interest in relation to this MPA, they do not necessarily represent the views of JNCC:

  • Oliver, G.P. and Drewery, J. (2013). New species of chemosymbiotic clams (Bivalvia: Vesicomyidae and Thyasiridae) from a putative ‘seep’ in Hatton-Rockall Basin, north-east Atlantic. Journal of the Marine Biological Association of the United Kingdom, 94: 389–403. – Describes two new species of bivalves which were discovered in The Hatton-Rockall Basin from around 1,180–1,200 m deep.


Knowledge gaps

As part of the UK Marine Monitoring and Assessment Strategy (UKMMAS), JNCC led the development of a UK Marine Biodiversity Monitoring Strategy, working with partners across the UK monitoring community. The Strategy spans UK territorial and offshore waters, focusing on biodiversity in the wider environment and within Marine Protected Areas.  Its aim is to implement efficient, integrated monitoring of marine biodiversity to provide the evidence needed for all the UK's policy drivers.

The Marine Directorate of Scottish Government, in partnership with JNCC and NatureScot, developed a Scottish Marine Protected Area (MPA) monitoring strategy. The Strategy spans Scottish territorial and offshore waters, focusing on biodiversity within Marine Protected Areas. The Strategy is supported by a series of annexes which provide more detail on monitoring methods, collaborative working, current monitoring and a two year forward look for MPA monitoring in Scottish waters.

The evidence collected during MPA monitoring surveys is used in combination with other available evidence to:

  • Enable assessment of condition of the features within sites;
  • Contribute to the 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.

More detail on offshore MPA monitoring can be found on the Offshore MPA monitoring webpage. A list of monitoring surveys and relevant reports can be found on the MPA monitoring survey reports webpage.

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


Conservation Advice

Last updated: March 2018

Updated formal conservation advice is now available for this MPA.  Further information on the approach used to develop this advice is available on our Conservation Advice webpages along with a Glossary of Terms used in JNCC's conservation advice and a short video explaining how to use the conservation advice packages. 

You must refer to this advice if you:

  • undertake an impact assessment for a plan or project that could impact the site;
  • provide information for such an assessment;
  • respond to specific measures to further the conservation objectives for the site; and 
  • consider the need to put new or additional management measures in place.

You may also find it useful to refer to this advice if you:

  • carry out any other activity that could impact the site.

We will engage with stakeholders to identify any lessons which JNCC can learn from customers who have used the advice, with a view to continuing to ensure it is fit-for-purpose.

The following table provides an overview of the components of the conservation advice, and provides hyperlinks to each of the products for this MPA. These elements together form JNCC’s formal conservation advice for this site and should be read in conjunction with each other. This updated advice replaces the previous Regulation 18 package for the site. This advice reflects the most up-to-date evidence held by JNCC (correct as of March 2018). 

Document Overview
Background Information Explains the purpose of the advice and when it must be referred to.

Conservation Objectives

Supplementary Advice on the Conservation Objectives (SACO)

The Conservation Objectives set out the broad ecological aims for the site. JNCC provides supplementary advice in the SACO which is essential reading to support interpretation of these conservation objectives.

You can use these documents to assess the impacts of your planned activity on the important attributes of the site.

Conservation Advice Statements

These statements provide a summary of the Supplementary Advice on the Conservation Objectives (SACO)

  • Site condition presents our up-to-date understanding of the condition of features within the site;
  • Conservation benefits which the site can provide, these help you understand what is important about the site and why it needs protecting; and
  • Conservation measures which JNCC considers are needed to support achievement of the conservation objectives. These provide clarity around measures needed to support restoration or maintenance of the feature(s) within the site.
Features, Activities, Sensitivities Tool (FeAST)

Provides an initial assessment of whether a proposed plan or project (or ongoing activity) may have an impact on a protected feature in the site.

FeAST identifies pressures associated with the most commonly occurring marine activities, and provides a detailed assessment of feature sensitivity to these pressures. A human activity is considered capable of affecting, other than insignificantly, a feature where the feature is known to be sensitive to associated pressures.

The sensitivity assessments provided in FeAST, should be used at an early stage of a plan or project when considering potential impacts of an activity.

These resources are available on JNCC's Resource Hub.



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