Darwin Mounds MPA

 

Status: Special Area of Conservation (SAC)

 

Darwin Mounds SAC lies at the north end of the Rockall Trough located approximately 160 km north west of Cape Wrath, Scotland, with depths between 710-1129m.

 

The site contains an extensive area of sandy mounds, each capped with multiple thickets of cold-water corals. Unlike most cold-water corals which attach to hard-surfaces, at this site the corals is growing on sand. The thickets of coral range in size from one to several metres in diameter and support many other species, such as starfish, sponges and large populations of xenophyophores. Xenophyophores are the world’s largest single celled organisms and are only found in deep-sea environments. They provide shelter for a range of small sea creatures, many of which are prey for larger species, and act as an elevated perch for filter feeders such as brittlestars.

 

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

 

Map displaying MPA boundary and

associated protected feature data.

Visit the JNCC MPA Mapper to further

view and explore data for this MPA.

 

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

* For the latest Annex I habitat resource figures, please see the link to the latest Habitats Directive Article 17 reporting in the Assessment tab.

 

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 at the top of the page and in JNCCs MPA mapper, with the evidence underpinning available in the Evidence tab.

 

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. These pressures are associated with activities taking place within or in close proximity to a protected site. Specific information on the conservation objectives relating to this SAC is provided in the Conservation Advice tab.


Site Timeline

The diagram below summarises the key milestones involved in the selection and designation of Darwin Mounds SAC.  More detail can be found within the Relevant Documentation.


Relevant Documentation

The documents referred to below and any other historical documents relating to Darwin Mounds SAC 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 Darwin Mounds SAC, and will reflect any additional information gathered since these documents were produced. Information about the SAC site selection process is also available on the JNCC SAC pages.

 




Summary

 

Last updated: October 2017

 

Information for this site summary was adapted from the SAC selection assessment and incorporates any further information gathered since this document was produced. Please refer to this document for further details and information sources.

 

Site overview: The Darwin Mounds is located approximately 160km north-west of Cape Wrath, Scotland at the north end of the Rockall Trough. The site consists of a large number of coral topped ‘sand volcanoes’ composed of sand overlying mud. The individual mounds are up to 75m wide and 5m high and are morphologically unique in UK waters. The mounds themselves are unusual geological features that are thought to have been formed by fluid expulsion from the seabed. The mounds are most elevated to the north of the site and diminish in height to the south. There are two denser regions of mounds in the north-east and north-west of the site. The north-east field of the Darwin Mounds measures approximately 13km by 9km and contains approximately 150 mounds, whereas the north-west field measures approximately 13km by 4km and contains approximately 75 mounds.

 

The mounds in the northern part of the site showed an acoustic signature of a “tail” which generally lies to the south west of the mound feature consisting of elongate to oval patches up to 500m long. The 'tail' feature of the mounds is thought to be unique globally. The tails are not topographically distinct from the surrounding seabed but are covered with a fine veneer of sand. They support substantial numbers of the xenophyophore, Syringammina fragilissima (a single celled organism that can grow up to 20cm in diameter), in densities greater than the surrounding seabed.

 

On the majority of the mounds there are also multiple colonies of Lophelia pertusa growing, which in many cases have formed thickets which arise from the surface of the mound. This site was the first observed record of cold-water coral reefs growing on sand at the time of discovery. Like the topography of the mounds, the frequency of coral communities diminishes towards the south of the mound field. Although the reef habitat on top of the mounds is formed primarily from Lophelia pertusa another cold-water coral, Madrepora oculata, is also present. The thickets of cold-water corals provide a habitat for echiuran worms, brittlestars, brisingiid starfish and sponges. Various fish have been observed among the mounds, but not at higher densities than the wider environment.

 

Within the Atlantic north-west approaches, Rockall Trough and Faroe-Shetland Channel Regional Sea where Darwin Mounds SAC is situated, there are three other SACs designated for the presence of Annex I reef: Anton Dohrn SAC, North West Rockall Bank SAC and East Rockall Bank SAC. Each site represents different types of Annex I reef. On the edge of the adjacent Scottish continental shelf regional sea Wyville Thomson Ridge SAC on the edge of the adjacent Scottish continental shelf regional sea is also designated for Annex I reef. The tail feature observed on mounds in the northern part of the Darwin Mounds site is thought to be globally unique from a geological perspective. Further detail on the evidence for this SAC can be found on the Evidence tab.

 

Site location:  Coordinates for this SAC can be found in the standard data form listed in the relevant documentation.

Site area:  1,377 km2, a similar size to the Brecon Beacons National Park (1,344 km2)

Site depth range:  710 – 1,129m.

Charting Progress 2 Biogeographic Region: Atlantic North-West approaches, Rockall Trough and Faroe-Shetland Channel. A small part of the site extends into the Scottish continental shelf biogeographic region.

 

Site boundary description

The boundary of the Darwin Mounds SAC is a simple polygon, fully enclosing the minimum area necessary to ensure protection of the Annex I feature. The boundary has been aligned with the area permanently closed to bottom trawling through the European Commission common fisheries policy (EC Regulation 602/2004).

As bottom trawling is a significant threat to the interest feature the proposed boundary includes a margin to ensure its protection. The maximum depth of water around the feature is 1,000-1,100m. Fishing vessels which are bottom trawling in the region need a minimum towline length of twice the depth of water in which they are fishing. Assuming a ratio of 2:1 fishing warp length to depth, the proposed boundary is defined to include a margin of 2,200m from the cold-water coral reefs.

 

Evidence

 

Last updated: October 2017

 

For a full overview of the data used to support site identification along with information on confidence in feature presence and extent see the Darwin Mounds SAC selection assessment. Data for this SAC have been primarily collected through JNCC-funded or collaborative surveys with other data obtained through other data sourcing.  The data gathered provide direct evidence confirming the presence of the protected features within the site. Additional survey data will be added to JNCCs MPA mapper in due course.

 

Survey and data gathering

  • Survey of Darwin Mounds and North West Rockall (2011)
    JNCC collaborated with the National Oceanography Centre and Plymouth University to carry out habitat mapping to assess the status of different benthic habitats in relation to human activities, especially deep-sea bottom trawling. Acoustic and underwater imagery data were collected.
  • RRS Charles Darwin Cruise 123C3-4 (2000)
    The cruise formed part of the continuing AMES undertaken by the National Oceanography Centre in waters to the north and west of Scotland. Seabed samples and underwater imagery were collected to study environmental parameters and benthic communities.
  • RRS Charles Darwin cruise 119C leg B (1999)
    The cruise was undertaken by the National Oceanography Centre and expanded on the work undertaken on the AFEN Atlantic Margin Environmental Survey (AMES). The cruise collected acoustic maps of the seafloor, along with photographic and video observations. Where possible, seabed samples were also collected to analyse selected environmental parameters.
  • Atlantic Frontier Environmental Network Survey (1998)
    The Atlantic Frontier Environment Network (AFEN; including JNCC) commissioned a survey to map and sample the seabed to the north and west of Scotland, allocated for oil and gas exploration in 1997. The aim of the survey was to provide the shape and texture of the seabed, the fauna and the physical processes affecting them, both of today and over the last 10-15,000 years. The Darwin Mounds were discovered on this cruise.

 

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


Additional relevant literature
References for further supporting scientific literature consulted during the identification of this site can be found in the site selection 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:

  • Huvenne V.A.I., Bett B.J., Masson D.G., Le Bas T.P. and Wheeler A.J. (2016) Effectiveness of a deep-sea cold-water coral Marine Protected Area, following eight years of fisheries closure. Biological Conservation, 200: 60–69.
  • Masson, D.G., Bett, B.J., Billett, D.S.M., Jacobs, C.L., Wheeler, A.J. and Wynn, R.B., (2003) The origin of deep-water, coral-topped mounds in the northern Rockall Trough, Northeast Atlantic. Marine Geology, 194: 159-180.
  • Bett, B.J. (2001) UK Atlantic Margin Environmental Survey: Introduction and overview of bathyal benthic ecology. Continental Shelf Research, 21: 917-956.
  • Bett, B.J., Billett, D.S.M., Masson, D.G., Tyler, P.A. et al. (2001) RRS Discovery Cruise 248: 07 Jul-10 Aug 2000. A multidisciplinary study of the environment and ecology of deep-water coral ecosystems and associated seabed facies and features (The Darwin Mounds, Porcupine Bank and Porcupine Seabight). National Oceanography Centre Cruise Report 36: 108. This cruise formed part of the work done by the National Oceanography Centre for the EU funded Atlantic Coral Ecosystem Study and ECOMOUND projects. These projects  investigated the geological processes underlying the formation of the Darwin Mounds, and studied the biology and ecology of cold water coral reefs.

 

Knowledge gaps
If you are aware of any additional data or relevant scientific papers for this site not listed here, please contact JNCC.

 

Conservation Advice

 

Last updated: June 2017

 

Conservation objectives set out the desired state for the protected feature(s) of an MPA. The conservation objectives for the protected feature within the Darwin Mounds SAC have been set based on current knowledge of the condition of the protected feature. Further information on feature condition and conservation objectives is provided in the Darwin Mounds conservation objectives and advice on operations document.

 

This information is useful if you are:

  • Preparing habitats regulations assessments 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; and/or
  • Developing, proposing or assessing an activity, plan or project that may affect the site.

 

The conservation objective for the Annex I reef at Darwin Mounds is: Subject to natural change, restore the reef back to favourable condition, such that the:

  • natural environmental quality is restored;
  • natural environmental processes are maintained; and
  • extent, physical structure, diversity, community structure and typical species representative of biogenic cold-water coral reef in the Atlantic North-West approaches, Rockall Trough and Faroe-Shetland Channel, 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 the Darwin Mounds SAC 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 the marine life information network (MarLIN).

JNCC also provides a list of activities occurring within the site and information on activity management 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 the 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 MarLINs 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; or
  • An authority responsible for putting management measures in place.

 

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

 

Activities and Management

 

Last updated: October 2017

 

Management status: Progressing towards being well managed

 

Information about the long-term recovery of cold-water coral populations is scarce but fisheries management measures are in place. Continued protection of the Darwin Mounds area combined with regular monitoring is necessary to obtain further insights in these processes (Howell et al 2014).

  1. The documentation of appropriate management information - conservation objectives, advice on activities capable of affecting the protected features of a site, and spatial information on the presence and extent of the protected features of a site.
  2. The implementation of management measures - management actions considered necessary to achieve the conservation objectives of a site.
  3. Site condition monitoring programmes – collecting the information necessary to determine progress towards a sites conservation objectives.
  4. Assessment of progress towards conservation objectives – using available information to infer whether or not a site is moving towards or has achieved its conservation objectives.
  • The conservation objectives and advice on activities capable of affecting the conservation status of the protected feature of this site are available under the conservation advice tab.
  • JNCC are in the process of improving our MPA conservation advice packages. Further information is available on our conservation advice pages.
  • Spatial information on the presence and extent of the protected feature of this MPA is available via JNCCs MPA mapper.
  • JNCC are in the process of developing downloadable MPA data packages where appropriate permissions to share datasets are in place.

 

Licensable activities

  • Whilst ‘licensable’ activities such as oil and gas exploration and production do not take place within Darwin Mounds SAC at present, any future proposals would have to comply with Article 6 (3) of the EU Habitats Directive 1992, which is transposed into UK law by the offshore Marine Conservation (Natural Habitats& c.) Regulations 2007 (as amended).
  • Our conservation advice supports the consents process by setting out the conservation objectives for the protected feature of this MPA and advice on activities that may result in pressures to which the protected feature is considered sensitive.
  • Further information on JNCCs role in the provision of advice for licensed activities in the UK offshore area is available on JNCCs offshore industries advice webpage

 

Site condition monitoring

Fishing vessel monitoring data is used to monitor compliance with the management measure in place. A baseline condition monitoring survey was undertaken in 2011 (reported in Howell et al 2014). Further information is provided in the Monitoring tab.

 

Assessment of progress towards conservation objectives

No long-term condition monitoring data is available to determine whether the MPA is moving towards or has reached its conservation objectives. Howell et al (2014) suggest that ecosystem recovery is still a long way off, as no signs of coral recolonisation and limited coral regrowth were recorded in damaged areas after eight years of closure to bottom-contacting fishing gear (since 2004). Further information is provided in the Assessment tab.

 

Monitoring

 

Last updated: October 2017

 

JNCC is currently leading on the development of a strategy for biodiversity monitoring across all UK waters, to include SAC monitoring. For SACs, 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 the 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 SAC will be provided when it becomes available.

 

Assessment

 

Last updated: October 2017

 

Assessments of the condition of designated features in offshore MPAs are required to report against our legal obligations. Ideally these assessments are based on observed data, and then measured against targets for predefined indicators. However, for MPAs in offshore waters the appropriate information is not always available particularly for seabed habitats, which are the main type of designated features within offshore MPAs. 

 

To address these challenges, JNCC has been an active partner in developing new approaches and tools for the assessment of habitats and species for a variety of national and international status reports. 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. The reports include the second cycle of the conservation status assessment reports under the EU Habitats Directive, Charting Progress 2 and the OSPAR Quality Status Report. 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 assessments, and contribute to the monitoring of marine biodiversity in UK waters.

 

Every six years, member states are also 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.  These assessments will also feed into six yearly reports on the state of the marine environment under the Marine Strategy Framework Directive, which aims to achieve good environmental status by 2020.

 

 

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