These plans are from the original UKBAP Tranches 1 and 2 (1995-1999)
For up-to-date information please visit The Biodiversity Action Reporting System (BARS)

Plans | Habitats | Saline lagoons

Habitat Action Plan

Saline lagoons

©Peter Wakely

Current Status

Lagoons in the UK are essentially bodies, natural or artificial, of salinewater partially separated from the adjacent sea. They retain a proportion of their seawater at low tide and may develop as brackish, full saline or hyper-saline water bodies.The largest lagoon in the UK is in excess of 800 ha (Loch of Stenness) although the restare much smaller and some may be less than 1 ha. Lagoons can contain a variety ofsubstrata, often soft sediments which in turn may support tasselweeds and stoneworts aswell as filamentous green and brown algae. In addition lagoons contain invertebratesrarely found elsewhere. They also provide important habitat for waterfowl, marshland birdsand seabirds. The flora and invertebrate fauna present can be divided into three maincomponents: those that are essentially freshwater in origin, those that aremarine/brackish species and those that are more specialist lagoonal species. The presenceof certain indigenous and specialist plants and animals make this habitat important to theUK's overall biodiversity.
There are several different types of lagoons, ranging from those separatedfrom the adjacent sea by a barrier of sand or shingle ('typical lagoons'), to thosearising as ponded waters in depressions on soft sedimentary shores, to those separated bya rocky sill or artificial construction such as a sea wall. Sea water exchange in lagoonsoccurs through a natural or man-modified channel or by percolation through, or overtoppingof, the barrier. The salinity of the systems is determined by various levels of freshwater input from ground or surface waters. The degree of separation and the nature of thematerial separating the lagoon from the sea are the basis for distinguishing severaldifferent physiographic types of lagoon.

Current factors affecting the habitat

The processes which lead to the natural development of some typesof lagoons are generally inhibited by human coastal activities. It is probable that theformation of new lagoons will not keep pace with the process of lagoon loss. Currentfactors affecting this habitat type are listed below.
Many lagoons, particularly in England and Wales, are naturally transient;salinity regimes change as succession leads to freshwater conditions and eventually tovegetation such as fen carr. Some formerly saline sites are now freshwater.
The bar-built sedimentary barriers of 'typical' coastal lagoons tend tonaturally move landwards with time. Lagoons behind them will eventually be in-filled asbar sediments approach the shore.
Pollution, in particular nutrient enrichment leading to eutrophication, canhave major detrimental effects. This may result from direct inputs to the lagoon or fromwater supply to the lagoon.
Artificial control of water (sea and fresh) to lagoons can have profoundinfluences on the habitat.
Many lagoons are often seen as candidates for infilling or land claim aspart of coastal development.
Some coastal defence works can prevent the movement of sediments along theshore and lead to a gradual loss of the natural coastal structures within which manycoastal lagoons are located.
The impact of coastal defences will be compounded by the effects of sealevel rise. One study in 1992 estimated that about 120 ha of coastal lagoons in England(10% of the existing resource in England) would be lost over the subsequent 20 years,mainly as a consequence of sea level rise.
Sea level rise may present opportunities for creation of new lagoonalhabitat where sea water inundates freshwater areas, including sites that were once coastallagoons.

Current Action

Legal status

In Great Britain 12 species of invertebrate and plant associatedwith lagoons are protected under the Wildlife and Countryside Act 1981. No lagoon speciesare listed for protection under the Wildlife (Northern Ireland) Order 1985.
Of the 177 lagoon sites surveyed in England, covering 1200 ha, just over50% occur within existing SSSIs and about 10% occur within NNRs and as many in LNRs. Fewerexamples are found in Wales where only between 5 and 10 lagoons are recognised followingrecent survey. 139 sites, covering about 3892 ha have been identified in Scotland, ofwhich 15% are SSSIs and less than 2% lie within NNRs. A preliminary study suggests thatthere may be 30 lagoonal habitat sites in Northern Ireland (of these only a few smallperched salt marsh pools are thought to be natural in origin). In Northern Ireland theywill all eventually fall within the ASSI/SPAs network.
Internationally important lagoons have been designated for their birdinterest as SPAs under the EC Birds Directive. Coastal lagoons are also listed as apriority habitat on Annex 1 of the EC Habitats Directive; the UK Government has identified10 candidate SACs under this Directive, some of which include several individual lagoonsites.

Management, research and guidance

Coastal groups are currently preparing shoreline managementplans for defined lengths of coast. The production of these plans will requireidentification of key habitats, including coastal lagoons, and confirmation of theirmanagement requirements.
Certain lagoons have an established research base and study group.

Action plan objectives and targets

Maintain the current area (c.5200 ha) of coastal saline lagoons.
Maintain the current number and distribution of coastal saline lagoons.
Maintain and improve, as necessary, the quality of coastal saline lagoons as measured by the retention of lagoonal specialist BAP Priority and Red Data Book species where these occur.
Create, by the year 2015, 120 ha of saline lagoon.

Proposed actions with lead agencies

Policy and legislation

Continue to take account of the coastal lagoon habitats in assessing the grant-aiding of coastal defence works. (ACTION: MAFF, NAW)
Identify abstractions known, or likely to be adversely affecting (through reduced freshwater flows) lagoonal habitats of nature conservation importance. Abstractions should be revoked or reduced where the review identifies this as necessary. (ACTION: EA, SEPA)
Review current marine aggregate extraction licences by 1997 as a means of assessing the combined impact of aggregate extraction on coastal processes relating to lagoons. This action is subject to the results of studies on the cumulative effects of individual aggregate extraction operations which are on-going. (ACTION: DETR, NAW)

Site safeguard and management

Continue notification of sites which meet the SSSI/ASSI guidelines ensuring that representation of the full range of lagoonal types is covered. (ACTION: CCW, EHS, NE, SNH)
Progress with the programme to designate lagoonal habitats as SPAs, Ramsar sites and SACs by 2004. (ACTION: DETR, NAW, SE)
Maintain and monitor the stable exchange of waters to and from lagoonal habitats as part of site management plans. (ACTION: CCW, EA, NE, SEPA, SNH)
Encourage the production of management plans for lagoonal sites especially SSSIs/ASSIs, NNRs, LNRs and NGO-owned nature reserves by 1998. These should include objectives for BAP priority species and may include objectives for all relevant Red Data Book species. Management objectives and actions for saline lagoons should be incorporated into broader management initiatives such as Local Environment Agency Plans and Estuary Management Plans. (ACTION: CCW, EHS, NE, SNH).
Contribute to the different stages of producing shoreline management plans (including guidance on their preparation) to ensure that processes relevant to coastal lagoons are taken into account (ACTION: CCW, EA, NE, Local Authorities, MAFF, WO).
In light of research results consider establishing a management scheme, or adapting existing schemes such as agri-environment schemes and managed realignment initiatives, to contribute to creating, by the year 2010, sufficient lagoonal habitat to offset losses of the last 50 years. This scheme should also contribute to maintaining the coastal lagoon and saline pond resource, despite losses due to sea level rise. (This is unlikely to be possible behind shingle bars/spits which should be preserved where possible as they are exceedingly rare structures in the UK). (ACTION: DETR, MAFF)
In so far as the legislation permits, the Government should take account of the potential benefits to lagoons when designating Nitrate Vulnerable Zones. (ACTION: DETR, NAW, SE)


Create a lagoons working group to define best management practices, lagoon creation and colonisation/re-introduction of characteristic species by 1996. (ACTION: CCW, NE, JNCC, MAFF, SNH)


Develop liaison within Europe to ensure best practice in lagoonal conservation is exchanged and developed. (ACTION: CCW, NE, JNCC, SNH)

Research and monitoring

Establish an inventory of all coastal lagoons currently of national and international importance by 1998. Where information is still inadequate, encourage surveys which assess the importance of lagoonal habitats. (ACTION: CCW, DETR, EHS, NE, JNCC, SE, SNH)
Consider the development of coastal geomorphological modelling techniques which could assist in an understanding of the retention and development of lagoonal and other habitats, and consider supporting an associated programme for the monitoring of sediment supply and movement where appropriate. (ACTION: MAFF, NAW, SE)
Assess the feasibility of using some derelict docks as sites for the creation of lagoons including for possible ex-situ conservation of threatened lagoonal species. (ACTION: CCW, NE, SNH)
Use saline lagoon habitat creation schemes to test methods and the approach for creating new habitat. Such opportunities may arise, for example, through coastal defence set-back and perhaps also land use by industry. (ACTION: CCW, NE, SNH)
Support research into the environmental requirements and other elements of the ecology and genetic viability of populations of certain key characterising lagoonal species. This would provide a sound basis for management. (ACTION: CCW, NE, SNH)

Communications and publicity

Raise public awareness by increasing links between schools, colleges and universities and local estuarine sites by providing educational resources and training on the interpretation of saline lagoonal habitats. (ACTION: DETR, NAW, SE)


The successful implementation of the action plan will have resourceimplications for both the private and public sectors. The data in Table 1 below provide apreliminary estimate of the likely resource costs to the public sector in the years 1997,2000 and 2010.
The data are based on targets whereby 700 hectares of lagoon habitat will beappropriately maintained and enhanced through to 2010. The figure of 700ha is provided forillustration and does not supercede any of the targets included in Section 4.
Habitat Type: Saline lagoons (£000 per annum)
Area to be maintained and enhanced (Ha) 1997 2000 2010
700 800 1,500 600
7. Key references
Bamber, R.N. 1997. Assessment of saline lagoons within Special Areas of Conservation.English Nature Research Report No. 235, English Nature, Peterborough.
Bamber, R.N. 1999. Assessment of saline lagoon resource in Wales. NaturalHistory Museum, London (ECM Report No. 646/99).
Sections on lagoons in Coastal Directories Series, eg:
Bamber, R.N. & Barnes, R.S.K. 1998. Chapter 3.4 Coastal Lagoons. In: C.F. Robson, S.S.Kaznowska, J.P. Doody, N.C. Davidson & A.L. Buck eds. Coasts and seas of the UnitedKingdom. Region 8 - Sussex: Rye Bay to Chichester Harbour. Coastal Directories Series,Joint Nature Conservation Committee, Peterborough.
Barnes R.S.K.1994. The brackish-water fauna of northwest Europe. An identificationguide to brackish-water habitats, ecology and macrofauna for field workers, naturalistsand students. Cambridge University Press, Cambridge.
Covey, R., Fortune, F., Nichols, D. & Thorpe, K. 1998. Marine NatureConservation Review Sectors 3, 4, 12, 13 & 15. Lagoons in mainland Scotland and the Inner Hebrides: area summaries. Coasts and seas of the United Kingdom MNCR Series,Joint Nature Conservation Committee, Peterborough.
Downie, A.J. 1996. Saline lagoons and lagoon-like saline ponds in England.English Nature Science No. 29, English Nature, Peterborough.
Pye, K. & French, P.W. 1993. Targets for coastal re-creation. English NatureScience No. 13, English Nature, Peterborough.
Smith, B.P. & Laffoley, D. 1992. Saline lagoons and lagoon-like habitats.English Nature Science No. 6, English Nature, Peterborough.

Thorpe, K. 1998. Marine Nature Conservation Review Sectors 1 & 2. Lagoons inShetland and Orkney: area summaries. Coasts and seas of the United Kingdom MNCRSeries, Joint Nature Conservation Committee, Peterborough.

Thorpe, K., Dalkin, M.J., Fortune, F. & Nichols, D.M. 1998. Marine NatureConservation Review Sector 14. Lagoons in the Outer Hebrides: area summaries. Coastsand seas of the United Kingdom MNCR Series, Joint Nature Conservation Committee,Peterborough.

Annex to thesaline lagoons habitat action plan: species

1. Background

1.1A number of species found only, or predominantly, in saline lagoons are listedas priority species under the UK Biodiversity Action Plan. The species considered to beassociated with saline lagoons are:

starlet sea anemone Nematostella vectensis

Ivell`s sea anemone Edwardsia ivelli

lagoon sandworm Armandia cirrhosa

the hydroid Clavopsella navis

lagoon sand shrimp Gammarus insensibilis

the lagoon seaslug Tenellia adspersa

Baltic stonewort Chara baltica

bearded stonewort Chara canescens

foxtail stonewort Lamprothamnium papulosum

bird`s nest stonewort Tolypella nidifica.

1.2Given the intimate association of the listed species with their lagoonalhabitat, and therefore between threats, actions and management for such species and thehabitat, it is considered appropriate to link the species with the saline lagoons habitataction plan. Consequently, all of the species (except the two anemone species for whichspecies action plans have already been published) are addressed through species statementsrather than being subject to individual species action plans. It is considered that thegroup steering the implementation of the habitat action plan will also address the speciesconcerned. It should be noted, however, that two species - Chara canescens and C.baltica - are also known from freshwater sites; this fact is reflected in the speciesstatements. The lagoons HAP does not encompass such sites and therefore these speciescannot be addressed solely by the saline lagoons HAP steering group.

1.3It should be noted that actions implemented for the saline lagoon habitatand for the species named here will also benefit other lagoon fauna and flora including anumber of other rare and/or specialist lagoonal species, eg Gammarus chevreuxi and Hydrobianeglecta.

2. Objectives for the species

2.1The objectives for the habitat will by default contribute to protection andconservation of the species with the exception of where they occur outside of salinelagoons. The following additional objectives apply to all the species

Maintain, and where appropriate enhance, existing populations and, whereappropriate, restore populations at former sites.

Maintain the range and number of sites including, where appropriate,through introduction to adjacent localities where existing localities become unsuitable.

3. Proposed action

Most of the actions listed for the habitat apply to the species and include anumber that are species-specific. The following additional generic actions should benoted.

Promote surveys to determine the full extent of each species including atformer localities. (ACTION: CCW, EHS, NE, SNH)

Ensure management and monitoring of relevant sites takes account of thespecies listed, and that species-related objectives and actions in management plans areacted on. (ACTION: CCW, EA, EHS, NE, SEPA, SNH)

Where appropriate, ensure habitat creation initiatives, including in thevicinity of present and former localities, take into account the requirements of thespecies. (ACTION: CCW, EHS, NE, LAs, SNH)

Where appropriate, determine the feasibility of former localities for thereintroduction of particular species. (ACTION: CCW, EHS, NE, LAs, SNH)

Where appropriate, consider further species-specific policy or legislativemeasures. (ACTION: CCW, DETR, DoNEI, EHS, NE, JNCC, NAW, SE, SNH)

Pass relevant information gathered during survey and monitoring to JNCC orBRC for incorporating into national databases. (ACTION: CCW, EHS, NE, SNH)

Provide information periodically to WCMC on the UK status of species tocontribute to up-to-date global red lists. (ACTION: JNCC)

Use the species as appropriate to raise awareness about saline lagoonhabitat conservation and management. (ACTION: CCW, DETR, EHS, NE, NAW, SE, SNH)

Key references

Local implementation

The following LBAPs are working on Saline lagoons:

Coastal Biodiversity Partnership Coastal Biodiversity Partnership Coastal Biodiversity Partnership Coastal Biodiversity Partnership Coastal Biodiversity Partnership Coastal Biodiversity Partnership Coastal Biodiversity Partnership Coastal Biodiversity Partnership Falkirk Area Biodiversity Action Plan Falkirk Area Biodiversity Action Plan Vale of Glamorgan Local Biodiversity Action Plan Isle of Wight Local Biodiversity Action Plan Teignbridge BAP Working for the Wealth of Wildlife - Anglesey's Local Biodiversity Action Plan A Local Biodiversity Plan for Pembrokeshire A Local Biodiversity Plan for Pembrokeshire A Local Biodiversity Plan for Pembrokeshire A Local Biodiversity Plan for Pembrokeshire Action for Wildlife in Nottinghamshire Dorset Biodiversity Initiative Cornwall’s Biodiversity vol 1, 2 and 3 Essex Biodiversity Partnership From Rio to Sussex, action for biodiversity Suffolk Local Biodiversity Action Plan Hampshire Biodiversity Partnership Working for Wildlife; the Northumberland Biodiversity Action Plan Norfolk Biodiversity Action Plan Norfolk Biodiversity Action Plan Lincolnshire Biodiversity Action Plan Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute Local Biodiversity Action Plan for Argyll and Bute

Publication details

Originally published in: Biodiversity: The UK Steering Group Report - Volume II: Action Plans (December 1995, Tranche 1, Vol 2, p233)
© Joint Nature Conservation Committee 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010