The fen raft spider was one of the first species to be included in English Nature's Species Recovery Programme. Since 1991 concerted efforts, including annual monitoring of population size, have been made to prevent extinction of the residual population at Redgrave and Lopham Fen. Efforts to increase the water supply in summer included the excavation of new pools, the deepening of existing pools and, most critically, the artificial irrigation of pools in the core of the spider's range. In dry years the spiders became completely confined to these irrigated pools. The vegetation around the pools was managed to maintain healthy growth of sedge and remove shading scrub. These measures helped to sustain the spider population until 1999 when the bore-hole that had drained the Fen was re-located and the natural hydrology restored. This was the culmination of a four-year programme of work, part-funded by the European LIFE fund, to restore conditions likely to favour recovery of the fen's internationally endangered plant communities. Although problems remain, particularly in re-establishing suitable vegetation over much of the fen and in controlling water quality, it is hoped that the spider population will be able to increase substantially over the next decade.
On the Pevensey Levels the fen raft spider population is much larger than at Redgrave and Lopham Fen. Although it is not regarded as endangered, regular monitoring will be undertaken to ensure that water quality and management at the site continue to favour the maintenance of a large population. Any species confined to just two localities is especially vulnerable to extinction. To reduce this risk, and help to ensure the future of the fen raft spider in the UK, English Nature aim to introduce the spiders to at least two other UK sites in the next ten years. DNA signatures will be used to examine the relationships between the UK populations and determine the most suitable material for these introductions.
Between 2010 and 2015, a translocation programme captive-reared spiderlings to reintroduce into sites in the Norfolk and Suffolk broads. These new populations are being carefully monitored to assess whether they are now self-sustaining.
The UK Biodiversity Action Plan
for this species is available at UK BAP