The Fen Raft Spider Dolomedes plantarius occurs at only two sites in the UK, and at one of these, Redgrave and Lopham Fen National Nature Reserve on the Suffolk/Norfolk border, it has been the subject of well-publicised conservation action. Helen Smith has analysed the information on spider distribution and numbers at the site in relation to this conservation action (Biol. Conserv. 95: 153-164). The site was affected by water absraction from a borehole, exacerbated by droughts, which led to its drying out. Major changes in vegetation occured, particularly scrub encroachment and a decline in the fen, which is dominated by Great Fen-sedge Cladium mariscus.