This is a static version of the conservation advice for this site, generated on 16/09/2019.
Please check the latest advice for this site at https://designatedsites.naturalengland.org.uk/
Natural England Conservation Advice for Marine Protected Areas
Isles of Scilly: Peninnis to Dry Ledge MCZ

Natural England guidance

This site collection contains Natural England’s conservation advice for this site. It fulfils Natural England’s responsibility under the Marine and Coastal Access Act 2009, to give advice on how to further the conservation objectives for the site, identify the activities that are capable of affecting the designated 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 MCZs
Site name: Isles of Scilly: Peninnis to Dry Ledge MCZ
Designation type: MCZ
Site identification: MCZ0008-08
Latest designation date: 31 May 2019
Designated features
(click to see site specific description):

Intertidal coarse sediment

Intertidal coarse sediment is found in 5 of the Isles of Scilly MCZs. The Isles of Scilly is unusual because it supports some areas of coarse sediment in sheltered conditions, without heavy tidal scour (Holme, 1983). A good example is the shore at Porth Hellick on St Mary's. Coarse sediment shores are generally exposed and fairly barren, but these conditions in Scilly mean that fairly diverse faunal communities can develop (Holme, 1983).

Intertidal coarse sediment is found in the sheltered bays on the St Mary's coastline: Old Town Bay, Porth Hellick and Pelistry Bay (Natural England (NE), 2013).


Intertidal mixed sediments

Intertidal mixed sediment habitat is uncommon and found at only a few sites in the UK (Natural England, 2014). In this MCZ a small area of this habitat is present on the St Mary's coastline (Natural England (NE), 2013).


Intertidal sand and muddy sand

Intertidal sand and muddy sand is present in 5 of the Isles of Scilly MCZs. This habitat is found in the sheltered bays on the St Mary's coastline: Old Town Bay, Porth Hellick and Pelistry Bay. Porth Hellick has a larger area of this habitat than the other 2 bays (Natural England (NE), 2013).


Intertidal under boulder communities

Intertidal underboulder habitat in the Isles of Scilly supports diverse communities, with a species composition which reflects the archipelago’s southerly location. The nationally rare orange peel bryozoan (Turbicellepora magnicostata) is a dominant species in Scilly, found nowhere else in the UK, and the usually subtidal featherstar Antedon bifida has been recorded here (Gall, 2011). Other nationally Rare species include the giant goby (Gobius cobitis) and Connemara clingfish (Lepadogaster candollei), whilst Scarce species include the cushion star (Asterina phylactica) and scarlet and gold star coral (Balanophyllia regia). UK Priority species often present are the stalked jellyfish (Lucernariopsis campanulata) and European eel (Anguilla Anguilla) (Gall, 2011).

This Priority habitat is found on sheltered to moderately exposed shores in the Isles of Scilly, with high exposure preventing community formation (Gall, 2011). Intertidal underboulder communities in this MCZ are focused around Old Town Bay, Porth Hellick and Pelistry Bay on the St Mary's coastline (Natural England (NE), 2013). Surveying of intertidal underboulder communities in the Isles of Scilly Special Area of Conservation was carried out in 2011, as part of the 'reef' feature. The communities surveyed were considered to be healthy and diverse.


Low energy intertidal rock

This habitat is present in 2 of the Isles of Scilly MCZ sites. Low energy intertidal rock is primarily found in Old Town Bay, with a small patch in Porth Hellick Bay (Natural England (NE), 2013).


Moderate energy intertidal rock

Moderate energy intertidal rock is found in 9 of the Isles of Scilly MCZ sites. This habitat is present along most of the St Mary’s coastline within the MCZ, with the exceptions of Old Town Bay, Porth Hellick and Pelistry Bay (Natural England (NE), 2013).


Spiny lobster (Palinurus elephas)

Spiny lobster is a designated feature in 9 of the 11 Isles of Scilly MCZ sites, all with a ‘recover' to favourable condition status. A UK Priority species for conservation, spiny lobster populations have seen national declines. This has been associated with the introduction of new fishing methods in the 1960’s (Goñi and Latrouite, 2005).

Adult spiny lobster inhabit complex rock and mixed sediment habitats in the Isles of Scilly, between depths of 20m and 90m, often in more exposed habitats (Holt and Kielly-Fletcher, 2016). Habitat use by juvenile spiny lobster is thought to differ from adults, but is poorly understood at present. Spiny lobster are mainly active during the night and are opportunistic feeders, eating a variety of molluscs, echinoderms and crustaceans. In the Atlantic they migrate onshore in spring before the reproductive season, moving offshore again by late autumn. Mating takes place in June-October, with females incubating carried eggs for 6-10 months until hatching occurs across March-June (Goñi and Latrouite, 2005).


Stalked jellyfish (Calvadosia cruxmelitensis)

In May 2019, this feature was designated within the Marine Conservation Zone (MCZ). Natural England is in the process of developing Conservation Advice for this feature, which will be added here in due course. In the absence of the site specific description, please refer to the ‘general information on the site features’ below.


Stalked jellyfish (Haliclystus spp)

Haliclystus auricula is a UK Priority Species for conservation and has undergone national declines. The species is found on western coasts of the UK (Neal, 2007) and has a conservation objective of ‘maintain in favourable condition’ in the Isles of Scilly MCZ.

This species is small, 2 – 2.5cm in height (Neal, 2007). Unlike more familiar jellyfish species they do not have a free swimming medusa stage, but instead live attached to seagrass and seaweed fronds throughout their life (Lobelle et al., 2013). H.auricula is a predator, using stinging cells on its tentacles to catch invertebrates from the water column, mainly tiny crustaceans such as copepods (Zagal, 2004).

Stalked jellyfish Haliclystus spp. have been identified in the lower intertidal and shallow water in Higher Town and Peninnis to Dry Ledge MCZs (Natural England (NE), 2013).


General information on the site features:
The general information on the designated features from the MCZ features catalogue is useful for understanding the designated features, and should be used in conjunction with the site specific information.
Designated area (ha): 330
Moderation/boundary changes: The site was designated on 12 December 2013. Stalked jellyfish (Calvadosia cruxmelitensis) was added as a protected feature on 31 May 2019.
Overlapping Protected Areas:

Last updated: 13th September 2019

Background information and geography

The Isles of Scilly are an archipelago situated approximately 28 miles off the south west coast of Cornwall, renowned for their pristine marine environment and diverse fauna. There are 11 MCZs in the Isles of Scilly, covering an area of approximately 30km2 in total.

Peninnis to Dry Ledge MCZ is situated towards the east of the main Scilly archipelago. The MCZ encompasses the whole south east coast of St Mary's, including a wide range of intertidal habitat, and supports diverse under boulder communities. In deeper water rocky reefs provide habitat for diverse communities, including sponges, anthozoans, hydroids and bryozoans (Irving and Northern, 2012). A large number of UK priority species are found at this site, including pink sea fans (Eunicella verrucosa), sea fan anemones (Amphianthus dohrnii), sunset cup coral (Leptopsammi pruvoti) and spiny lobster (Palinurus elephas) on subtidal rocky substrate (Lieberknecht et al., 2011). Stalked jellyfish (Calvadosia campanulata and Haliclystus auricula) are also found here and giant gobies (Gobius cobitus) and ocean quahog (Arctica islandica) have been recorded (Lieberknecht et al., 2011).

Peninnis to Dry Ledge MCZ overlaps with the Isles of Scilly Special Area of Conservation (SAC). The SAC is designated to protect the archipelago’s intertidal mudflats and sandflats, sandbanks, rocky reefs, shore dock (Rumex rupestris) and grey seals (Halichoerus grypus). The MCZ adds to this by protecting specific intertidal rock and sediment habitats, spiny lobster and stalked jellyfish (Haliclystus auricula and Calvadosia cruxmelitensis).

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.

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 Marine Conservation Zone and the individual habitats and species for which the site has been designated.

The conservation objective of each of the zones is that the protected habitats and species:

  1. Are maintained in favourable condition
  2. Are brought into favourable condition if they are not already in favourable condition

For each protected habitat favourable conditions means that within a zone:

  1. Its extent is stable or increasing
  2. Its structure and functions, its quality, and the composition of its characteristic biological communities (including diversity and abundance of species forming part of, or inhabiting the habitat) are sufficient to ensure that its condition remains healthy and does not deteriorate.

Any temporary deterioration in condition is to be disregarded if the habitat is sufficiently healthy and resilient to enable its recovery.

For each species of marine fauna, favourable condition means that a population within a zone is supported in numbers which enable it to thrive, by maintaining:

  1. The quality and quantity of its habitat
  2. The number, age and sex ratio of its population

Any temporary reduction in number of a species is to be disregarded if the population is sufficiently thriving and resilient to enable its recovery.

Any alteration to a feature brought about entirely by natural processes is to be disregarded when determining whether a protected feature is in favourable condition.

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

Designated features:

  • Intertidal coarse sediment
  • Intertidal mixed sediments
  • Intertidal sand and muddy sand
  • Intertidal under boulder communities
  • Low energy intertidal rock
  • Moderate energy intertidal rock
  • Spiny lobster (Palinurus elephas)
  • Stalked jellyfish (Calvadosia cruxmelitensis)
  • Stalked jellyfish (Haliclystus spp)


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 September 2019


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: 20th March 2017


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: enquiries@naturalengland.org.uk




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