Summary details for Argenna patula (Simon, 1874)

Distribution

Coastal from southwest Scotland southwards round to The Wash, but the majority of sites are in East Anglia and the Thames Estuary. The distribution is restricted by the number of suitable rivers, estuaries and saltmarshes. The species is widespread on the coasts of western Europe.

Habitat and ecology

Estuaries, saltmarsh. The spider occurs among strandline litter and under stones on the banks of tidal rivers or on estuaries and saltmarshes, and may be frequent where it occurs. Adults of both sexes are found in May and June, females until October.

Status

Apparently not scarce in suitable habitat, though limited by this.

Threats

Pollution on some rivers and the loss of saltmarsh to land reclamation may threaten the species at some sites. There has been a massive loss of saltmarsh on parts of the east coast where erosion has been attributed to relative sea level rise resulting from a combination of land falling following the retreat of the last Ice Age and sea rising due to global warming. In Essex typical losses of around 20% per estuary, with one site approaching 50%, have been reported over the fifteen-year period 1973-1988 and have continued unabated between 1988 and 1998.

Management and conservation

Retain strandline litter in soft-coast habitats. Managed realignment, including the controlled breaching of sea walls, may provide new areas of suitable habitat. Text based on Dawson, I.K., Harvey, P.R., Merrett, P. & Russell-Smith, A.R. (in prep.).