Ponds - Habitat Action Plan 

Ref 2/H10 Habitat Action Plan 10
Plan Author: Norfolk Wildlife Trust
Plan Co-ordinator: Waterbodies Topic Group
Plan Leader: Environment Agency
Final Version 6 April 2010
Plan Duration: Five Years

Action Plan Summary

Current Status

National Status

  • Ponds declined in both number and quality during much of the last century as their economic functions ceased. There is no longer any real place today for ponds for watering farm horses, for clay for house building or for marling poor soil. Consequently, ponds have been filled in, built on or just simply neglected, often then becoming filled with scrub and silt.
  • Conversely, the number of ponds in Britain increased by approximately 11.1 per cent between 1998 and 2007, to an estimated total of 487,000 ponds in 2007; however, this was preceded by many decades of decline and at the same time, the quality of lowland ponds decreased (Countryside Survey 2007). The 1998 Lowland Pond Survey estimated that there were 228,900 ponds in lowland areas.
  • Ponds are widespread throughout the UK, but high-quality examples are now highly localised, especially in the lowlands. In certain areas, high quality ponds form particularly significant elements of the landscape, e.g. Cheshire Plain marl pits, the New Forest ponds, pingos of East Anglia, mid-Wales mawn pools, the North East Wales pond landscape, the forest and moorland pools of Speyside, dune slack pools, the machair pools in the Western Isles of Scotland, and examples of Habitats Directive Annex I pond habitats across Northern Ireland.
  • Ponds, for the purpose of UK BAP priority habitat classification, are defined as permanent and seasonal standing water bodies up to 2 ha in extent which meet one or more of the following criteria:
  • Habitats of international importance: Ponds that meet criteria under Annex I of the Habitats Directive.
  • Species of high conservation importance: Ponds supporting Red Data Book species, UK BAP species, species fully protected under the Wildlife and Countryside Act Schedule 5 and 8, Habitats Directive Annex II species, a Nationally Scarce wetland plant species, or three Nationally Scarce aquatic invertebrate species.
  • Exceptional assemblages of key biotic groups: Ponds supporting exceptional populations or numbers of key species, based on: (i) criteria specified in guidelines for the selection of biological SSSIs (currently amphibians and dragonflies only); and (ii) exceptionally rich sites for plants or invertebrates (i.e. supporting ≥30 wetland plant species or ≥50 aquatic macro-invertebrate species).
  • Ponds of high ecological quality as classified by the PSYM (the Predictive SYstem for Multimetrics): This is a method for assessing the biological quality of still waters in England and Wales. Plant species and / or invertebrate families are surveyed using a standard method; the PSYM model makes predictions for the site based on environmental data and using a minimally impaired pond dataset. Comparison of the predicted and observed data gives a percentage score for the pond's quality.
  • Other important ponds: Individual ponds or groups of ponds with a limited geographic distribution recognised as important because of their age, rarity of type or landscape context e.g. pingos, duneslack ponds, machair ponds.
  • Priority habitat ponds can be readily identified by standard survey techniques such as those developed for NVC, Common Standards Monitoring, the National Pond Survey or for specific species groups. It is recognised that most ponds will be well below the 2ha size.
  • Ponds will need to be distinguished from other existing priority habitat types. The general principle is that, where the standing water element is functionally a component of another priority habitat and that priority habitat definition takes account of the standing water element, then it should be treated as part of that habitat. For example: small water bodies within blanket bog should be considered as part of the blanket bog priority habitat, but ponds in heathland (which are not dealt with through the heathland HAP) should be considered under the pond priority habitat. Agreement has been reached with the lake HAP group that the pond priority habitat will cover most water bodies up to 2 ha while the lake priority habitat will cover most water bodies greater than 2ha. As with other potentially overlapping priority habitat types, a small proportion of cases will need to be individually assessed to decide how they are best dealt with.
  • Estimates, based on the relatively small pond data sets currently available, suggest that around 20 per cent of the c.400,000 ponds outside domestic curtilage in the UK might meet one or more of the above criteria.

Norfolk Status

  • There is little information on the density, location or quality of ponds within Norfolk, and this needs to be collected and collated. (At the time of writing, the National Pond Monitoring network had only six ponds on file from Norfolk, all surveyed over a decade before).
  • Nonetheless, Norfolk has one of the most diverse ranges of habitats in Britain (see below), and one of the greatest varieties of pond characteristics occurring within it. Norfolk also contains a great number of ponds, with South Norfolk historically being one of the most pond-rich landscapes in England (Rackham 1986). In this area, the soil type is predominantly clay and there is a long history of clay abstraction. Clay was the primary building material for houses and farm buildings in south Norfolk. Clay was sourced locally to the new building, and as a result, many farms and homesteads have a pond in the pit which was left behind.
  • Across Norfolk, but primarily in the north and central parts, a great many ponds arise from former marl pits, where clay was dug for soil improvement.
  • Other ponds may have originated more naturally as dune slacks, pingos (both temporary ponds), fluctuating meres and isolated coastal reedbed ponds. Ponds have also been created through quarrying, the creation of moats, as medieval fish ponds, ornamental ponds, for livestock watering and as stone or brick pits. Within the Norfolk Broads, a range of ponds occurs within wet woodland.
  • Ponds provide habitats for a wide range of species, some of which are reliant on a series of ponds and associated habitat for survival; for example great crested newts. Species such as great crested newt and natterjack toad rely not just on ponds, but also on networks of ponds within suitable terrestrial habitats that are used for connectivity and hibernation.
  • Ponds are features that occur in many BAP habitats that are common within the wider landscape of Norfolk. These include:
  • Fens
  • Coastal sand dunes
  • Wet woodlands
  • Lowland calcareous grasslands
  • Lowland heathlands and dry acid grasslands
  • Lowland meadows and pastures
  • Lowland mixed deciduous woodlands
  • Lowland wood-pasture and parkland
  • UK and Norfolk BAP species associated with the Pond HAP include:
  • Pillwort Pilularia globulifera
  • Stonewort species e.g, Tolypella intricata & T. glomerata
  • Great crested newt Triturus cristatus
  • Water vole Arvicola terrestris,
  • Otter Lutra lutra
  • Natterjack toad Bufo calamita,
  • Shining ram's-horn snail Segmentina nitida
  • Crucian carp Carassius carassius
  • Data on the extent, species and quality of ponds in Norfolk is currently incomplete, although excellent records of great crested newt, natterjack toads, dragonflies and molluscs, among other species, have been collected by naturalists in recent years. In-depth surveys of ponds at Manor Farm in North Norfolk have been carried out by Dr Carl Sayer of University College London, colleagues from the University of East Anglia and others.
  • Ponds currently of note in Norfolk in the top PSYM categories (high, very high) include How Hill Turf Pond (1990) and Thompson Common Pingo 2 (1992), according to the National Pond Monitoring Network.
  • Of the ponds that do exist, many are in poor condition; as well as existing within BAP habitats, high numbers of ponds are isolated within arable fields and these are of variable quality. It should also be noted that some excellent ponds occur in improved pasture that is not of BAP quality. However, there are a great number of ponds that are of value to biodiversity in their present state and that value should be judged by assessments of all species, including plants, vertebrates and invertebrates utilising the pond; the value of ephemeral ponds, especially within clusters of ponds, should also be recognised. With this in mind, management advice should be largely site specific and rooted in survey work.

Current factors affecting the habitat

  • Pond density across the country has reduced as a result of the infilling of ponds. Ponds are dynamic systems and this loss of a landscape network may lead to a lesser diversity of wildlife as ponds become more isolated from one another. The loss of terrestrial habitats and buffer zones associated with ponds in areas of intensive land use can have an impact on the biodiversity in the pond. The resulting increased isolation of ponds from other ponds may have important implications for biodiversity at the landscape scale, as several species may need a network of ponds for their long-term survival.
  • Development is one major cause of the loss of pond sites. Historically, infilling has been one of the largest causes of pond loss in Norfolk, although this has probably slowed in recent years. In the latter half of the twentieth century, as ponds lost their economic value, they were often filled as part of farming practice. However, between 1990 and 1996, there was a high turnover of ponds, with an estimated 17,000 ponds lost but an estimated 15,000 new ponds made (Lowland Pond Survey 1998).
  • Direct loss of ponds can occur through residential/industrial development and road improvement (widening of roads and junctions). With both Norwich and Thetford named as growth points, there will be a significant rise in development in Norfolk over the next 20-30 years, much of which will need to be situated on greenfield sites. It is therefore important, now more than ever, that domestic gardens, urban parks, allotments and ponds be managed sympathetically for wildlife and biodiversity, in order to try and ameliorate the effects of this development as much as possible.
  • Ponds are vulnerable to pollution because their small size restricts their ability to dilute pollutants. Pollution, both chemical and organic, is known to critically damage pond wildlife and creates many management problems. Ponds can be detrimentally damaged in areas of intense arable land use, suffering from nutrient enrichment as a result of runoff from fertilised fields. Runoff from roads (including silt, salt and oil), septic tanks and industrial units will also have a deleterious influence on ponds
  • Non - native species such as Australian swamp stonecrop Crassula helmsii, floating pennywort Hydrocotyle ranunculoides , goldfish Carassius auratus, least duckweed Lemna minuta and parrot's feather Myriophyllum aquaticum can displace native species and may bring about detrimental habitat change.
  • Poor management of ponds has in many cases led to their decline. Today, ponds are viewed to be of little monetary value so are frequently neglected, often leading to succession and terrestrialisation. In other cases, a lack of knowledge about appropriate management can lead to ponds becoming damaged through detrimental actions such as over-deepening and the inappropriate stocking of plants or fauna. In arable settings, ponds may not only be isolated and lack a terrestrial buffer, but also, ploughing close to them can also cause over-steeping of the sides and siltation; many ponds in arable settings are also surrounded by scrub, often contributing to decline by causing shading and a build up of leaf matter. Neglect of banks, especially when grazing ceases, frequently leads to scrub development and willow growth within the pond. However, it should be noted that some apparently neglected ponds and many ephemeral ponds are of great interest for biodiversity and that survey work is vital to inform management decisions.
  • Fishery management is often not wholly appropriate for wider biodiversity, as the ponds are managed for sport species rather than for native ones and such ponds may suffer high levels of disturbance.
  • The loss of ponds from a natural habitat will have considerable effects on species diversity, and the populations of species within that habitat.

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Current Action in Norfolk

Legal

  • Most ponds are only protected by virtue of their protected species, or in association with other BAP habitats. The legal status of the great crested newt, natterjack toad and water vole offers protection for ponds.
  • Norfolk County Council's Ecologist comments on all Norfolk County Council highways improvement schemes, where the scheme has potential to impact directly or indirectly on a pond or watercourse.
  • Ponds are a priority consideration when commenting on planning applications and restoration schemes for Minerals, Waste and Highway Planning.

Management, research and guidance

  • Norfolk County Council provides pond management advice and its Countryside Conservation Grant Scheme provides some funding for the restoration of private ponds.
  • The Norfolk Non-native Species Initiative was launched in 2008 to promote the prevention, control and eradication of invasive, alien species.
  • The Norfolk County Wildlife Site (CWS) system takes into account the quality of ponds present within them when the designation is placed and encompasses criteria for the selection of ponds as CWS.
  • Higher Level Stewardship (HLS) includes grant aid for pond creation and restoration as part of larger HLS schemes.
  • Natural England's target for waterbodies within SSSIs states that ponds should be in good condition by 2010.
  • The National Trust is using 'ecological restoration techniques' to restore shallow ponds (The National Trust, 2009).
  • The Broads Authority’s Lake Restoration Strategy includes waterbodies less than 5ha in size. Work to restore and manage ponds, including turf ponds, also takes place within the Broads; this includes mud pumping and fish removal, advice to landowners and awareness raising/training.
  • Pond Conservation's Important Areas for Ponds (IAP) project aims to identify ponds of high biodiversity importance within geographical areas that support large numbers of high quality ponds. Conservation will be focused on the most valuable sites, either of National or European importance according to species assemblages. Pond Conservation's National Pond Monitoring Network assesses the ecological quality of ponds in Britain and monitors long term trends in pond numbers and biodiversity by collating existing pond survey data and co-ordinating future survey work. It also promotes the use of standardised survey techniques, particularly the PSYM method for assessing pond ecological quality and provides training in this method. Pond Conservation's Million Ponds Project aims to create an extensive network of new ponds across the UK. Ultimately, the aim is to reverse a century of pond loss, ensuring that once again the UK has over one million countryside ponds. For further information on all these initiatives, see www.pondconservation.org.uk.
  • Norfolk Wildlife Trust's Pingo Mapping Project (NWT, 2009) mapped and assessed the condition of pingo sites across Norfolk. A similar NWT audit of parishes in South Norfolk in 2004 recorded ponds in selected parishes and also developed methods for mapping and identifying ponds.
  • On behalf of the Norfolk Biodiversity Partnership, a study was carried out in 2008 of non-Broads lakes in Norfolk by the Environmental Change Research Centre (University College London). This sought to compile existing ecological knowledge for freshwater lakes (0.5 ha and greater) outside the Broads, and to identify sites that would be worthy of surveys to identify their conservation potential (Hughes, Sayer and Davidson, 2008).
  • Research on ponds and crucian carp in North Norfolk has also recently been carried out by CEFAS and UCL (Sayer et al, in prep).
  • Despite the positive action taking place, ponds and their associated biodiversity appear to be under-recorded in Norfolk. There remains an outstanding need for further research into the location and value of ponds, their biodiversity and the priorities for targeting advice, restoration/re-creation and habitat linkage.

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Action Plan Objectives and Targets

National

  • Identify where high quality pond sites are and what features characterise them using PSYM (the Predictive SYstem for Multimetrics) This system uses a number of aquatic plant and invertebrates measurements combined to give a value that represents the waterbody's overall quality.
  • Maintain a net number of high quality pond sites as identified using the PSYM. There will inevitably be some turn-over in high quality sites (i.e. some will be lost, and some gained). In addressing this, and other targets, particular emphasis should be placed on maintaining functional pond networks, maintaining water quality and species meta-populations.
  • Maintain the quality of flagship pond sites, a sub-set of approximately 1% of high quality ponds, ensuring they are monitored and that their quality is maintained ensuring these flagship sites do not degrade. These can also be used as 'example' ponds, demonstrating 'best practice' techniques for land owners.
  • Restore pond sites that are below high quality status to deliver Species Action Plan targets.
  • Targets for pond restoration are based on ultimately restoring c1,000 sites/year; however the target is staggered, starting at 50 sites/year, then rising progressively by 50 sites/year until the target of 1,000 sites/year is reached in 2022.
  • Create new pond sites of high quality potential thus creating a new network of ponds with clean water and high biodiversity potential. New ponds often have a high conservation value (Lowland Pond Survey 1998).Target ponds should be located in a wide range of landscape types to maximise regional biodiversity. Their creation should not damage the value of existing sites or areas. Creation of (a) pond mosaics/complexes, (b) new ponds that increase landscape connectivity or form protective networks, and c) new sites that are targeted to support pond SAP species is particularly encouraged. Ponds cannot be counted against this target if they are created as mitigation for destruction of existing high quality ponds.
  • The definition of 'high quality potential' has yet to be agreed at a national level. However, a provisional definition is 'ponds located in areas where they drain a semi-natural surface-water catchment and are unlikely to be significantly impacted by man after use (e.g. in appropriately stocked with fish)'.

Norfolk

Action Plan Objectives

  • Establish a more accurate figure for the extent, location and condition of ponds in Norfolk.
  • Maintain the existing resource of ponds in the county.
  • Promote and support the appropriate restoration of existing ponds and the creation of new ponds in locations that will benefit biodiversity.
  • Develop and extend provision of management advice and awareness of the biodiversity value of ponds.

Action Plan Targets

  • Maintain the existing resource of ponds in the county through advisory work, protection under the land use planning system and increased promotion of the importance of ponds.

Advisory work should include developing the concept of 'flagship' pond networks as examples of best practice and as education facilities. Advice should also include education/training for advisors and landowners, and should address the need to reduce the negative effects of fragmentation, by ensuring the buffering of existing sites, developing ecological networks and linking existing sites.

Advice should also recognise the need for survey work into species utilising ponds, to ensure that management work is not detrimental to biodiversity and the development of any generic advice needs to stress the need for survey wherever possible. Advisors may require training in survey methods in order to better evaluate the biodiversity of ponds and discussion about the problems of balancing the needs of different taxa may need to be debated as part of this.

  • Restore 30 ponds a year in order to improve their wildlife value. At least 50 per cent of the restored/re-established area should be adjacent to existing lowland meadow/pasture or other semi-natural habitat.
  • Re-establish or create five ponds of high wildlife value a year, avoiding damage to existing BAP habitats. New pond sites of high quality potential should be part of creating a new network of ponds with clean water and high biodiversity potential. Any new creation should not damage the value of existing sites or areas. Ponds cannot be counted against this target if they are created as mitigation for destruction of existing high quality ponds.

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