Britain’s biggest spider is thriving in East Anglia

Fen raft spider ENGSUS00120120920151221
Fen raft spider ENGSUS00120120920151221

A project to safeguard the future of Britain’s biggest spider by relocating some from a Suffolk fen was hailed a success on Halloween.

The fen raft spider was found in only two places in the UK: the Suffolk Wildlife Trust’s Redgrave and Lopham Fen and the Pevensey Levels in Sussex.

Such limited distribution meant they were in danger of extinction but a pioneering translocation project, headed by Dr Helen Smith , an ecologist contracted by Natural England under the Species Recovery Project, means the 7cm leg span spider can now be found at SWT’s Carlton Marshes and Castle Marshes and RSPB land close to Strumpshaw Fen in the Norfolk Broads.

More than 1,000 nursery webs were counted on SWT Carlton Marshes where Redfgrave and Lopham spiderlings were released five years ago.

Dr Smith said: “These large and beautiful spiders have really made these new sites home.

“This is a species that is clearly able to thrive in the Broadland grazing marshes that have been so carefully restored by conservation organisations in recent years.

“It’s already made a great start on colonising the area’s extensive ditch networks and, in the process, has taken a big step back from the brink.”

The RSPB said on Saturday: “With over 480 nursery webs counted this season (July-October), compared with 184 in 2014, this new population puts the spider in a much more secure position as a UK species.”

Fen raft spiders are semi-aquatic and detect prey by feeling vibrations on the water surface. They are the only European spider that eats vertebrates, catching small fish and tadpoles, yet they are fiercely protective mothers who carry sacks of 700 eggs with them until they hatch.