Abundance of non-native crabs in intertidal habitats of New England with natural and artificial structure

摘要: Marine habitats containing complex physical structure (e.g., crevices) can provide shelter from predation for benthic invertebrates. To examine effects of natural and artificial on the abundance intertidal juvenile crabs, 2 experiments were conducted in Kingston Bay, Massachusetts, USA, July to September, 2012. In first experiment, was manipulated a two-factor design that placed high 3 one-week periods test both substrate type (sand vs. rock) presence or absence (mesh grow-out bags used aquaculture, ∼0.5 m(2) with 62 mm(2) mesh openings). The Asian shore crab, Hemigrapsus sanguineus, small individuals green Carcinus maenas, observed only treatments rocks bag plus rocks. Most crabs (<6 mm carapace width) whereas H. sanguineus occurred wide range sizes. second levels oyster-shell established using muddy sand low zone: without shells, oyster live oysters. Replicate deployed weekly 7 weeks randomized complete block design. All collected C. maenas (1-15 width), numbers differed 6-fold among treatments, most present oysters (29.5 ± 10.6 m(-2) [mean S.D.]) fewest shells (4.9 3.7 m(-2)). Both (cobble rocks). attraction consisting plastic living could potentially impact aquaculture operations.