Essex Specialities. 4: the spider Baryphyma duffeyi
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pressures and rising sea levels. Many of the Thames Marshes have been reclaimed for industrial
development, with the extensive use of vertical concrete -capped iron pilings along the waterfront
leaving very little salt marsh (Merrett in Bratton 1991). With the abandonment of older industrial
sites next to the Thames, there is now enormous pressure from initiatives such as the 'Thames
Gateway' to redevelop, often for high value riverside housing. It seems unlikely that the importance
of small areas of fragile salt marsh will be adequately taken into account. Sea levels around Essex
are rising relative to the land by some 6mm a year, a combination of the land sinking following the
retreat of the last Ice Age and sea level rise as a result of global warming. This is causing erosion of
salt marshes and at the present rate most of the habitat will have been lost within a few decades.
Managed realignment, where traditional hard sea defences are replaced by softer, more responsive
and natural defensive beaches or the sea is allowed to reform salt marshes inland of the existing
defensive wall, is a contentious approach to manage the coastline sustainably (Gibson 2000). There
are some projects under way but the approach is unlikely to help along much of the Thames.
Baryphyma duffeyi should therefore probably now be considered nationally vulnerable.
Figure 3. photograph of Baryphyma duffeyi male © P.R. Harvey
Acknowledgements
I would like to thank the other members of the Essex Spider Group (David Carr, Ken Hill and Ray
Ruffell) for their help and encouragement in surveying the spiders of Essex and Eric Philp for
providing details of Kent records of Baryphyma duffeyi.
Essex Naturalist (New Series) 17 (2000)