Objectives:The objective of the project was to collate available information on ponds in the Norfolk Coast AONB, prioritise ponds for restoration and undertake restoration work in conjunction with interested landowners. The aim of the initial phase was to collate currently available information on ponds in the AONB, identify where further information, survey or ground-truthing is required and make a provisional prioritisation of ponds on which to focus initial restoration work, based on a range of factors, in preparation for future work (survey / ground truthing and restoration).
Available information on ponds in the AONB past and present was collated from a variety of sources including UCL data holdings, data held by Norfolk Pond Project (NPP) partners and files held by key conservation landowners/land managers including the Holkham Estate, Norfolk Wildlife Trust, RSPB and The National Trust. In addition AONB pond species data were obtained from the Norfolk Biodiversity Information Service (NBIS).
GIS software was used to create a map containing multiple shapefiles showing all the known pond locations within the boundary of the Norfolk Coast AONB. Where possible, ponds, which have associated species records, were identified using the location data as provided by the data owner. Shapefiles were converted into compatible .kml files in order to upload them onto Google Maps, where a complete map could be viewed of all known pond locations and species data.
Three 5 x 5 km squares were randomly placed within the Norfolk Coast AONB boundary, using Google Earth Pro. High-resolution satellite imagery was used to locate any ponds that had not yet been identified on an Ordnance Survey (OS) map. The purpose of this exercise was to determine the error margin between identified ponds on OS maps and existing but unmapped ponds. In total, 204 known ponds (from the datasets queried) lie within the boundaries of the 5 x 5 km ground truthing squares. An additional 37 ponds were located within these squares using high-resolution satellite imagery, increasing the total number of identified ponds by a moderate 18%. This result implies that, although a significant number of ponds had already been identified prior to this exercise, the number of additional ponds subsequentlyidentified following desk-based ground truthing is large enough to justify more comprehensive, field based ground-truthing of the Norfolk Coast AONB. Although analysis of satellite imagery is a useful approach, it is recommended that ground-truthing should be completed in the field, using local knowledge, in order to ensure full coverage of sites within the Norfolk Coast AONB. Field ground truthing would also be useful where the GIS and satellite data make it difficult to differentiate between 'duplicates' ponds and those ponds that are very very close neighbours (e.g. where there is high tree coverage)
A total of 1307 ponds were identified following the data exercise. Pond type was broken down into a number of categories, including field ponds, gravel pit ponds, hedgerow ponds, estate lakes, woodland ponds and ghost ponds. Field pond and hedgerow pond were the most common types. Thus, from across the data sources we were able to obtain pond information from, 94 were characterised by species data. The table (below) summarises the number of ponds with data for different species groups.
|Species||Number of Ponds|
|Great Crested Newt||47|
The data generated show that there is a real paucity of species data available relative to the number of ponds. This highlights;
Currently the species data available for ponds in the AONB are scant/sporadic being largely limited to records for individual species with only a few ponds subjected to multi-species surveys. Nonetheless, there are large numbers of ponds in the AONB (1307 identified in this study) and it is clear that several key pond species are present which would benefit from future conservation work.
Farmland pond restoration. To date, pond management and restoration has received little attention in the AONB. Nonetheless, one flagship project, conducted at the landscape-scale where several overgrown ponds are managed to reduce terrestrialisation, might help to inspire future work.
There would be huge benefits associated with focused pond creation within the AONB. This could take three major angles;