Natural England Conservation Advice for Marine Protected Areas
Portsmouth Harbour SPA

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: Solent EMS
Site name: Portsmouth Harbour SPA
Designation type: SPA
Site identification: UK9011051
Latest classification date: 28 February 1995
Qualifying features
(click to see site specific description):

General information on the site features:
You can find generic information on the qualifying species from the following websites: The generic information on the supporting habitats for the qualifying features is useful for understanding the qualifying features, and should be used in conjunction with the site specific information.
Designated area (ha): 1248.77
Moderation/boundary changes: Portsmouth Harbour was classified as a Special Protection Area on 28 February 1995. There have been no changes to the SPA boundary since the site was classified.
Component Sites of Special Scientific Interest (SSSI):
Overlapping Protected Areas:

Last updated: 13th September 2019

Background information and geography

Portsmouth Harbour is a large, industrialised estuary. Together with the adjacent Chichester and Langstone Harbours, it forms one of the most important sheltered intertidal areas on the south coast of England.

The harbour has been classified as a Special Protection Area (SPA) due to internationally and nationally important numbers of birds and specifically protects the following features: dark-bellied Brent goose; red-breasted merganser; dunlin; and black-tailed godwit.

Portsmouth Harbour SPA is composed of extensive intertidal mudflats and sandflats with seagrass beds, areas of saltmarsh, shallow coastal waters, coastal lagoons and coastal grazing marsh.

At low tide the extensive mudflats are exposed, the water drained by channels and creeks uniting to form a narrow exit into the Solent. There is comparatively little freshwater input to Portsmouth Harbour. The largest input is the River Wallington, which flows into Fareham Creek in the north-west of Portsmouth Harbour. The estuarine sediments support rich populations of intertidal invertebrates, which provide an important food source for overwintering birds.

There are approximately 77 ha of seagrass beds in Portsmouth Harbour, which are found mainly in the north-west of the harbour. These beds include both Zostera marina (found on the low shore) and Zostera noltii (on the upper to mid shore). The seagrass beds are amongst the most extensive in Britain and are an important food source for dark-bellied Brent goose. The saltmarsh areas are mainly comprised of cordgrass (Spartina) swards and provide feeding and roosting areas for overwintering birds.

Areas outside the SPA contain important supporting habitats for the birds that use the site, including coastal grazing marsh and agricultural land. Details of these can be found online, in particular via the Solent Wader and Brent Goose Strategy.

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.

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 aims of the Wild Birds Directive, by maintaining or restoring:
  • the extent and distribution of the habitats of the qualifying features
  • the structure and function of the habitats of the qualifying features
  • the supporting processes on which the habitats of the qualifying features rely
  • the populations of each of the qualifying features
  • the distribution of qualifying features 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: 14th September 2018


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: 14th September 2018


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


Close