Priority Pond criteria

The criteria used to identify ‘priority ponds’ under the UK Biodiversity Action Plan are listed below. We estimate that around 20% of the 500,000 or so ponds in the UK (excluding garden ponds) will meet one or more of the criteria. These waterbodies are, therefore, sites which should be given priority for protection for their wildlife interest.

1. Habitats of high conservation importance

Ponds that meet criteria under Annex 1 of the Habitats Directive, supporting the following habitat types: 3110 Oligotrophic waters containing very few minerals of sandy plains (Littorelletalia uniflorae), 3130 Oligotrophic to mesotrophic standing waters with vegetation of the Littorelletea uniflorae and/or Isoeto-Nanojuncetea, 3140 Hard oligo-mesotrophic waters with benthic vegetation of Chara spp, 3150 Natural eutrophic lakes with Magnopotamion or Hydrocharition – type vegetation, 3160 Natural dystrophic lakes and ponds, 3170 Mediterranean temporary ponds, 3180 Turloughs, 2190 Humid dune slacks, or 21A0 Machairs (in Ireland).  Read about the criteria here.

2. Ponds with species of high conservation importance

These are Red Data Book species, 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.

*Note that priority status originally required at least three Nationally Scarce invertebrate species to be present in a single season National Pond Survey 3-minute sample because of the frequency of several water beetle species formerly regarded as Nationally Scare. Following the Foster (2010) review of water beetle status (, it is now more appropriate to treat ponds with one Nationally Scarce species as priority habitats.

3. Ponds with exceptional populations or numbers of key species

This is based on

(i) criteria specified in guidelines for the selection of biological Sites of Special Scientific Interest (currently amphibians and dragonflies only)

(ii) exceptionally rich sites for plants or invertebrates (supporting 30 or more wetland plant species or 50 or more aquatic macroinvertebrate species).

For information about pond survey methods click here.

4. Ponds of high ecological quality

These are ponds classified in the top category for ecological quality (a score of 75% or more), as assessed by the standardised method for assessing the biological quality of still waters in England and Wales – the Predictive System for Multimetrics (PSYM).

5. Other important ponds

These are 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.