Natural England Conservation Advice for Marine Protected Areas
Isles of Scilly Complex SAC

Natural England guidance

This site collection contains Natural England's conservation advice for this site. It fulfils Natural England’s responsibility under the Conservation of Habitats and Species Regulations 2017 (as amended), to give advice on how to further the conservation objectives for the site, identify the activities that are capable of affecting the qualifying features and the processes which they are dependent upon.

Natural England's conservation advice for this site is made up of a number of components. You will need to consider: Additional information for consideration:

Site information

Overarching site: Isles of Scilly Complex SAC
Site name: Isles of Scilly Complex SAC
Designation type: SAC
Site identification: UK0013694
Latest designation date: 20 May 2004
Qualifying features
(click to see site specific description):

General information on the site features:
The generic information on the qualifying features is useful for understanding the qualifying features, and should be used in conjunction with the site specific information.
Designated area (ha): 26849
Component Sites of Special Scientific Interest (SSSI):
Overlapping Protected Areas:

Last updated: 15th March 2019

Background information and geography

The Isles of Scilly are a granite archipelago situated approximately 28 miles off the south west coast of Cornwall, renowned for their pristine marine environment and diverse fauna. Due to the archipelago’s southerly location, lack of coastal influences and range of exposures, species assemblages here are different from the mainland UK. A range of warmer water species are noticeably more prevalent on Scilly (Barne et al., 1996). The Isles of Scilly Special Area of Conservation (SAC) encompasses all of the main islands and outlying rocky islets and protects a range of habitats. Rocky reefs in Scilly stretch from the intertidal to deep circalittoral reefs and are recognised for the diversity of species they support. These include corals, sponges, seaweeds and bryozoans. The nationally rare orange peel bryozoan Turbicellepora magnicostata is found on intertidal rock in the Isles of Scilly, but nowhere else in the UK (Selley et al., 2014). Priority species for conservation on the reefs include pink sea fans Eunicella verrucosa, sea fan anemones Amphianthus dohrnii and sunset cup corals Leptopsammia pruvoti (Gall, 2011) (Lewis et al., 2008).

Extensive intertidal sandflats are present in the shallow water between the islands and again support a wide range of species, including some not often found in the intertidal. The largest of these sandflats is found off the south-east coast of St Martins. These sandflats often extend into the subtidal, where they support extensive and well-studied Zostera marina seagrass beds, and diverse subtidal sediment communities.

In addition to habitats the Isles of Scilly SAC is designated for supporting a sizeable population of grey seals Halichoerus grypus, which are present all year round and shore dock Rumex rupestris on a number of the islands.

The Isles of Scilly SAC overlaps with 10 of the 11 more recently designated Marine Conservation Zones (MCZs). The MCZs complement the SAC designation by offering protection to species and habitats that are not protected by the SAC. These include specific intertidal rock and sediment habitats, spiny lobster Palinurus elephas and two species of stalked jellyfish Calvadosia campanulata and Haliclystus auricular. There is also an SPA in Scilly, designated for breeding seabirds.

Site maps

Use the MAGIC website to see site maps, including habitats, species and other marine designations.

These maps are based on best available evidence, there are some caveats associated with the maps on MAGIC.

There are some instances where the feature, subfeature or supporting habitat name varies on MAGIC from the conservation advice. The alternative names are listed on

The dynamic nature of habitat features and supporting habitats for mobile species is illustrated where data is available, as new evidence becomes available these maps will be updated with our current knowledge of their known extent.

Conservation objectives

The site’s conservation objectives apply to the site and the individual species and/or assemblage of species for which the site has been classified (the "Qualifying features" listed above).

The objectives are to ensure that, subject to natural change, the integrity of the site is maintained or restored as appropriate, and that the site contributes to achieving the Favourable Conservation Status of its qualifying features, by maintaining or restoring:
  • the extent and distribution of qualifying natural habitats and habitats of the qualifying species
  • the structure and function (including typical species) of qualifying natural habitats
  • the structure and function of the habitats of the qualifying species
  • the supporting processes on which qualifying natural habitats and the habitats of qualifying species rely
  • the populations of each of the qualifying species
  • the distribution of qualifying species within the site

Qualifying features

Refer to the site information table above for the list of features within this site.

This should be read in conjunction with the accompanying supplementary advice section, which provides more detailed information to help achieve the objectives set out above, including which attributes should be maintained and which restored.

The conservation objectives apply under the Habitats Regulations, and must be considered during a Habitats Regulation Assessment, including an Appropriate Assessment.

The conservation objectives and accompanying supplementary advice provide a framework to inform the management and measures needed to conserve or restore the European site, and the prevention of deterioration and significant disturbance of its qualifying features.

Where the objectives are met, the site will be considered to show a high level of integrity, and to be contributing to achieving the aims of the Habitats Regulations.

Supplementary Advice on Conservation Objectives

See supplementary advice on conservation objectives for this site, which aim to describe the range of ecological attributes that are most likely to contribute to a site’s overall integrity.

Last updated: 13th September 2019

Advice on Operations

See the advice on operations for this site to view information on the sensitivity of features in this site to the pressures exerted by different activities.

Last updated: 13th March 2020

Advice on Seasonality

See the advice on seasonality for this site, to view the months in which each mobile feature occurs in this site.

Last updated: 15th March 2019

Feature Condition

In 2016, Natural England trialled and rolled out a new Marine Protected Area (MPA) condition assessment methodology that provides robust results and information on the condition of marine features designated within MPAs in England. With guidance from National teams and using all available evidence and condition monitoring data, Area Teams conduct these assessments following a standardised approach that assesses if the feature and sub feature conservation targets set for each MPA have been met.

To date, condition assessments have been completed for a number of features in a range of marine Special Areas of Conservation (SACs) by the National and Area Teams. Further marine habitat features in SACs and other MPAs will continue to be assessed in the future. The new method can now also be applied to complete habitat and species condition assessments for other MPAs in England, whilst still meeting the different processes in place to report on the results of condition of features in Marine Conservation Zones (MCZs) and Special Protection Areas (SPAs). Different processes are currently in place to decide and report on the condition of non-marine habitat and species features of SACs.

The main part of the assessment process is directly undertaken and stored here on Natural England’s Designated Sites View. The details for the most recent assessments of this site can be found here.

Management measures

If you are carrying out an environmental assessment, planning an operation or assessing an operation or proposal, it is important to consult with the following organisations where applicable. To find out if any management measures, byelaws or other restrictions apply to your activity see the management measure page or you can use the following links for more information.

The Marine Management Organisation license, regulate and plan marine activities in the seas around England and Wales so that they’re carried out in a sustainable way.
Environment Agency are responsible for regulating major industry and waste, water quality and resources, fisheries, inland river, estuary and harbour navigations, conservation and ecology.
Offshore Petroleum Regulator for the Environment and Decommissioning (OPRED) regulates oil and gas, CCS and gas storage activities in the marine environment.

Further information

For further information relating to this designated site you can refer to the following resources:
Site specific information: Other information:
For further information about this site contact: Natural England enquiries Telephone: 0300 060 3900. Email: