Suffolk Wildlife Trust’s Grove Farm Nature Reserve is situated in the Black Bourn Valley, not far from Bury St. Edmunds.

The site initially covered 62ha of mixed arable, woodland and marshland with 11 neglected farm ponds. Today the reserve has expanded to 89ha and with funding from Freshwater Habitats Trust’s (then called Pond Conservation) Million Ponds Project in 2010, nine new ponds were created, bringing the total to 20 ponds. In 2011 the nationally scarce Tassel Stonewort Tolypella intricata was recorded at the site, found in a recently managed farm pond.

The record of Tassel Stonewort was one of the reasons Grove Farm is included in the Flagship Ponds project – an opportunity to learn more about, and help to protect this rare species. The project funded a comprehensive survey of ponds by national stonewort recorder, Nick Stewart, to survey 18 new or restored ponds on the reserve. After considerable ‘fossicking’ Nick was triumphant and found a small fragment of the Tassel Stonewort, confirming the 2011 record! He went on to find another Nationally Scarce stonewort: Tolypella glomerata (Clustered Stonewort) and three other relatively common species in early succession newly created ponds: Chara vulgaris (Common Stonewort), Chara virgata (Delicate Stonewort) and Chara globularis (Fragile Stonewort).  The discovery of five stoneworts in one site qualifies it as one of Plantlife’s Important Stonewort Areas.

The Flagship Ponds project worked with the reserve staff and volunteers to trial a translocation of Tassel Stonewort to other waterbodies on the reserve. Many of the ponds are in the early stages of succession so this was an ideal time to test this technique. Receptor ponds were selected on criteria such as water levels, level of cattle access and poaching (management that Tassel Stonewort favours), and amount of competition by other aquatic and emergent species. On 3rd October 2017 a large bucketful of clay and thin layer of surface organic matter was taken from two points at the donor pond (where the stonewort had historically been seen – as oospores are thought to be able to lie dormant for up to 100 years or so, and where it was found in 2017) at a depth of 60cm, and through thick masses of Broadleaved Pondweed which was then removed, leaving just mud in the bucket. Photos were taken and a translocation form was completed at each of the four recipient ponds indicating aspects that might help draw conclusions on the stonewort’s favoured habitat features.

Will it translocate at all and if so, will it do so in the livestock hoof prints or the seasonally dry ‘mini-ponds’ that mimic ditches where it occurs elsewhere in Suffolk? Will it tolerate turbid water, or dense vegetation cover like its donor pond? At this point we simply don’t know! We will return to monitor the stonewort’s progress this year… and in the years to come, helping to build up evidence of how to conserve this rare species.

Location: Suffolk

Accessibility: Some Flagship Pond sites are accessible to the public, and some are not. If in doubt, consult maps for rights of way, look online for site information, or contact the site manager, and follow any instructions on site. It is up to you to check whether you require permission to visit and access the ponds on a site.

Site owners/managers: Suffolk Wildlife Trust