Table 1.

Comparison of densities (mean ± standard error) of benthic epifaunal and infaunal taxa, and total amphipods and bivalves, across treatments, grouped by order or roughly equivalent clade. The core (area of 15.7 cm2 by 10 cm deep) was sieved through a 500 μm mesh sieve. Annelids were excluded from analysis due to their poor preservation. Letters in parentheses: (i) for introduced or (n) for native.

SpeciesNo CageC. maenasH. oregonensisPartial CageFull Cage
Amphipoda
Ampithoe valida (i)  1.8 (0.7)  3.4 (2.2)  0.4 (0.4)  3.2 (1.1)  1.5 (1.0)
Corophiidae spp.  0.1 (0.1)  0.0 (0.0)  0.0 (0.0)  0.0 (0.0)  0.3 (0.3)
Grandidierella japonica (i)14.5 (2.8)  5.3 (1.6)  6.4 (2.6)11.7 (2.1)18.5 (4.6)
Monocorophium acherusicum (i)  1.4 (1.1)  0.0 (0.0)  0.0 (0.0)  0.0 (0.0)  0.0 (0.0)
Monocorophium spp.  1.6 (1.1)  1.7 (1.6)  0.2 (0.2)  1.5 (0.5)  0.8 (0.5)
Sinocorophium c.f. alienense (i)  2.8 (3.6)  1.1 (2.2)  4.8 (7.0)  4.2 (8.3)  2.3 (1.7)
Cumacea
Nippoleucon hinumensis (i)  6.9 (3.3)  1.9 (0.9)  1.0 (0.5)  6.3 (3.5)  7.8 (3.5)
Bivalvia
Gemma gemma (i)  3.4 (2.0)  3.4 (1.4)  1.0 (0.6)  2.5 (0.7)  1.0 (0.4)
Potamocorbula amurensis (i)  3.5 (1.4)  1.1 (0.5)  5.0 (3.0)  1.8 (2.4)  6.3 (1.0)
Limecola balthica (i)  0.1 (0.1)  0.1 (0.1)  0.0 (0.0)  0.0 (0.0)  0.0 (0.0)
Isopoda
Gnorisphaeroma oregonensis (n)  0.0 (0.0)  1.1 (1.1)  0.2 (0.2)  0.7 (0.7)  0.0 (0.0)
Ostracoda
Osctracoda spp.  0.5 (0.4)  0.3 (0.2)  0.4 (0.2)  1.0 (0.5)  0.5 (0.5)
Cephalaspidea
Haminoea c.f. vesicula (n)  0.4 (0.2)  0.0 (0.0)  0.0 (0.0)  0.0 (0.0)  0.0 (0.0)
Tanaidacea
Sinelobus c.f. stanfordi (i)  4.6 (2.9)  0.0 (0.0)  0.2 (0.2)  0.2 (0.2)  0.0 (0.0)
Total amphipods22.1 (3.4)11.6 (5.3)11.8 (2.3)21.8 (4.1)23.3 (5.8)
Total bivalves  7.0 (2.9)  4.7 (1.5)  6.0 (3.6)  4.3 (1.5)  7.3 (3.4)