Stow-cum-Quy Fen is a little known, yet outstandingly important Site of Special Scientific Interest (SSSI) in Cambridgeshire – not far from National Trust’s famous Wicken Fen.

The site is home to a variety of ponds, some of which are Coprolite pits; large elongate pools that were excavated in the late 19^th Century in order to mine mineral deposits which were used as fertiliser. Coprolite mining was a boom industry in Cambridgeshire and brought great riches to this area. The mineral deposits were originally thought to be dinosaur dung but recent research reveals that the phosphate rich seams were more likely to have comprised of the remains of marine molluscs, deposited during the Jurassic. Other ponds on Quy Fen are likely to be stock watering ponds, with further ponds created more recently.

The ponds are largely free from pollution and contain a remarkable range of freshwater life like the rare Clustered Stonewort Tolypellla glomorata, uncommon wetland plants like Lesser Water-plantain Baldellia ranunculoides, Water Violet Hottonia palustris and Fringed Water-lily Nymphoides peltata. Sadly our surveys for wetland plants failed to relocate any bladderworts (Utricularia sp.) which are  sensitive carnivorous submerged water plants, previously recorded at Quy Fen and mentioned on the SSSI notification. The site also provides important breeding ponds for Common toad, is home to a wide range of dragonflies and water beetles, and also supports a population of water vole.

The Flagship Ponds project has supported the site managers by funding a much needed survey of all ponds for wetland plants and invertebrates, this information will be used as a baseline to inform management and track how rare species are responding. Our work also engaged with local Bottisham Village College, students testing the nutrient status of the ponds and surrounding ditches and drains. The water testing highlighted that Quy Fen is particularly important in the context of an otherwise intensively farmed landscape where water is often polluted.