ABSTRACT
Settlement of echinoderm larvae was measured using artificial collectors at three sites in the rocky subtidal zone (10 m depth) on the Atlantic coast of Nova Scotia. Each site consisted of two adjacent habitats: a sea urchin (Strongylocentrotus droehachiensis) dominated barren ground and a kelp bed (Laminaria spp.). Suspended collectors made of 0.05 m2 panels of plastic turf were deployed at two heights, 0.2 m and 2 m above the bottom in each habitat, and sampled bi-weekly between June and November 1992. A recently metamorphosed ophiuroid was the most abundant species and showed a distinct settlement pulse in late July at each site. During this pulse, there were significant differences in the number of ophiuroid settlers both between habitats within sites and among sites. At two of the sites, there were significantly lower numbers of settlers in collectors near the bottom in the kelp than in the barren ground. In two of the sites, the numbers of settlers in collectors suspended 2 m above the bottom also was lower over kelp beds than over the barren grounds. Reduced settlement of echinoderm larvae in kelp beds may result from higher post-settlement mortality in kelp beds or lower supply of larvae due to hydrodynamic factors.
