Ground-living spiders (Araneae) at polluted sites in the Subarctic

Spiders were studied around the Pechenganikel smelter combine, Kola Peninsula, north-western Russia. The average spider density was 6-fold greater and the density of Linyphiidae specimens 11.5-fold higher at slightly polluted sites, compared with heavily polluted sites. Altogether, 18 species from 10 families were found at heavily polluted sites, the theridiid Robertus scoticus clearly dominating (23.3 % of identifiable specimens), also Neon reticulatus (9.6 %), Thanatus formicinus (9.6 %) and Xysticus audax (8.2 %) were abundant. The most numerous among 58 species found at slightly polluted sites were Tapinocyba pallens (18.5 %), Robertus scoticus (13.7 %), Maso sundevalli (9.5 %) and Alopecosa aculeata (8.2 %). The family Linyphiidae dominated at slightly polluted sites, 64 % of species and 60 % of individuals; compared with heavily polluted sites, 23 % and 38 % respectively.